GNU COBOL Programmer’s Guide For Version 2.1 [23NOV2013] Gary L. Cutler (cutlergl@gmail.com). This manual documents GNU COBOL 2.1, 23NOV2013 build. GNU-COBOL Copyright 2002-2007 Keisuke Nishida Copyright 2007-2012 Roger While Copyright 2013-2013 Ron Norman (RWCS for GNU COBOL) Document Copyright 2009-2014 Gary L. Cutler Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License [FDL], Version 1.3 or any later version published by the Free Software Foundation; with Invariant Section ”Introduction”, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled ”GNU Free Documentation License”. GNU COBOL 2.1 [23NOV2013] Programmer’s Guide i Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.1. Additional Reference Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2. Introducing COBOL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 1.2.1. Why YOU Should Learn COBOL . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.2.2. Programmer Productivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1.3. So What is GNU COBOL?. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1.3.1. Language Reserved Words . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.3.2. User-Defined Words . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 1.3.3. Case Insensitivity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 1.3.4. Readability of Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 1.3.5. Divisions Organize Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 1.3.6. Copybooks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 1.3.7. Structured Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 1.3.8. Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 1.3.9. Table Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 1.3.10. Sorting and Merging Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 1.3.11. String Manipulation Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 1.3.12. Screen Formatting Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 1.3.12.1. A Sample Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 1.3.12.2. Color Palette and Video Attributes. . . . . . . . . . . . . . . . . . 20 1.3.13. Report Writer Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 1.3.14. Data Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 1.3.15. Syntax Diagram Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 1.3.16. Format of Program Source Lines . . . . . . . . . . . . . . . . . . . . . . . . . 26 1.3.17. Program Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 1.3.18. Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 1.3.19. Literals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 1.3.19.1. Numeric Literals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 1.3.19.2. Alphanumeric Literals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 1.3.19.3. Figurative Constants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 1.3.20. Punctuation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 1.3.21. LENGTH OF. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 1.3.22. Interfacing to Other Environments . . . . . . . . . . . . . . . . . . . . . . . 37 2. CDF - Compiler Directing Facility . . . . . . . . . . . 39 2.1. COPY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 2.2. REPLACE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 2.3. >>DEFINE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 2.4. >>IF. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 2.5. >>SET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 2.6. >>SOURCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 2.7. >>TURN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 3 June 2014 Contents ii GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 3. IDENTIFICATION DIVISION . . . . . . . . . . . . . . . 53 4. ENVIRONMENT DIVISION . . . . . . . . . . . . . . . . . 55 4.1. CONFIGURATION SECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 4.1.1. SOURCE-COMPUTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 4.1.2. OBJECT-COMPUTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 4.1.3. REPOSITORY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 4.1.4. SPECIAL-NAMES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62 4.1.4.1. Alphabet-Name-Clause . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 4.1.4.2. Class-Definition-Clause . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 4.1.4.3. Switch-Definition-Clause . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 4.1.4.4. Symbolic-Characters-Clause . . . . . . . . . . . . . . . . . . . . . . . . . . 71 4.2. INPUT-OUTPUT SECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 4.2.1. SELECT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 4.2.1.1. ORGANIZATION SEQUENTIAL . . . . . . . . . . . . . . . . . . . . 78 4.2.1.2. ORGANIZATION LINE SEQUENTIAL. . . . . . . . . . . . . . 80 4.2.1.3. ORGANIZATION RELATIVE . . . . . . . . . . . . . . . . . . . . . . . 82 4.2.1.4. ORGANIZATION INDEXED . . . . . . . . . . . . . . . . . . . . . . . . 84 4.2.2. MULTIPLE FILE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 4.2.3. SAME RECORD AREA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 5. DATA DIVISION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 5.1. Data Definition Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 5.2. FILE SECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93 5.2.1. File/Sort-Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 5.2.2. FILE-SECTION-Data-Item . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 5.3. WORKING-STORAGE SECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 5.4. LOCAL-STORAGE SECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 5.5. LINKAGE SECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104 5.6. REPORT SECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 5.6.1. Report Group Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111 5.6.2. REPORT SECTION Data Items . . . . . . . . . . . . . . . . . . . . . . . . . 113 5.7. SCREEN SECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115 5.8. Special Data Items . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 5.8.1. 01-Level Constants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 5.8.2. 66-Level Data Items . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121 5.8.3. 77-Level Data Items . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122 5.8.4. 78-Level Data Items . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 5.8.5. 88-Level Data Items . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124 5.9. Data Description Clauses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 5.9.1. ANY LENGTH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 5.9.2. AUTO. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 5.9.3. AUTO-SKIP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 5.9.4. AUTOTERMINATE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128 5.9.5. BACKGROUND-COLOR. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 5.9.6. BASED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130 Contents 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide iii 5.9.7. BEEP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131 5.9.8. BELL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132 5.9.9. BLANK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 5.9.10. BLANK WHEN ZERO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134 5.9.11. BLINK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 5.9.12. COLUMN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 5.9.13. CONSTANT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138 5.9.14. EMPTY-CHECK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 139 5.9.15. ERASE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 5.9.16. EXTERNAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141 5.9.17. FALSE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142 5.9.18. FOREGROUND-COLOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143 5.9.19. FROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144 5.9.20. FULL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145 5.9.21. GLOBAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 5.9.22. GROUP INDICATE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 5.9.23. HIGHLIGHT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148 5.9.24. JUSTIFIED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 5.9.25. LEFTLINE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151 5.9.26. LENGTH-CHECK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152 5.9.27. LINE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153 5.9.28. LOWLIGHT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155 5.9.29. NEXT GROUP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156 5.9.30. NO-ECHO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 5.9.31. OCCURS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158 5.9.32. OVERLINE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161 5.9.33. PICTURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162 5.9.34. PRESENT WHEN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170 5.9.35. PROMPT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171 5.9.36. REDEFINES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172 5.9.37. RENAMES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173 5.9.38. REQUIRED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174 5.9.39. REVERSE-VIDEO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 175 5.9.40. SECURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176 5.9.41. SIGN IS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177 5.9.42. SOURCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178 5.9.43. SUM OF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179 5.9.44. SYNCRONIZED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181 5.9.45. TO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183 5.9.46. TYPE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184 5.9.47. UNDERLINE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185 5.9.48. USAGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186 5.9.49. USING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196 5.9.50. VALUE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197 3 June 2014 Contents iv GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 6. PROCEDURE DIVISION . . . . . . . . . . . . . . . . . . . 201 6.1. PROCEDURE DIVISION USING . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202 6.2. PROCEDURE DIVISION CHAINING . . . . . . . . . . . . . . . . . . . . . . . . 204 6.3. PROCEDURE DIVISION RETURNING . . . . . . . . . . . . . . . . . . . . . 206 6.4. PROCEDURE DIVISION Sections and Paragraphs . . . . . . . . . . . 207 6.5. DECLARATIVES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208 6.6. Table References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211 6.7. Qualification of Data Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212 6.8. Reference Modifiers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 6.9. Arithmetic Expressions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215 6.10. Conditional Expressions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218 6.10.1. Condition Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218 6.10.2. Class Conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219 6.10.3. Sign Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221 6.10.4. Switch-Status Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222 6.10.5. Relation Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 223 6.10.6. Combined Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225 6.10.7. Negated Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 226 6.11. Use of Periods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227 6.12. Use of VERB/END-VERB Constructs . . . . . . . . . . . . . . . . . . . . . . . 229 6.13. Concurrent Access to Files. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231 6.13.1. File Sharing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231 6.13.2. Record Locking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233 6.14. Common Clauses on Executable Statements . . . . . . . . . . . . . . . . . 235 6.14.1. AT END + NOT AT END . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235 6.14.2. CORRESPONDING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 236 6.14.3. INVALID KEY + NOT INVALID KEY . . . . . . . . . . . . . . . . 238 6.14.4. ON EXCEPTION + NOT ON EXCEPTION . . . . . . . . . . . 238 6.14.5. ON OVERFLOW + NOT ON OVERFLOW . . . . . . . . . . . . 239 6.14.6. ON SIZE ERROR + NOT ON SIZE ERROR . . . . . . . . . . . 239 6.14.7. ROUNDED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240 6.15. Special Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243 6.16. Intrinsic Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245 6.16.1. ABS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246 6.16.2. ACOS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247 6.16.3. ANNUITY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248 6.16.4. ASIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249 6.16.5. ATAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250 6.16.6. BYTE-LENGTH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251 6.16.7. CHAR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252 6.16.8. COMBINED-DATETIME . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253 6.16.9. CONCATENATE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 254 6.16.10. COS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 255 6.16.11. CURRENCY-SYMBOL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256 6.16.12. CURRENT-DATE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257 6.16.13. DATE-OF-INTEGER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258 6.16.14. DATE-TO-YYYYMMDD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 259 Contents 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide v 6.16.15. DAY-OF-INTEGER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260 6.16.16. DAY-TO-YYYYDDD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261 6.16.17. E . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 262 6.16.18. EXCEPTION-FILE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263 6.16.19. EXCEPTION-LOCATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264 6.16.20. EXCEPTION-STATEMENT . . . . . . . . . . . . . . . . . . . . . . . . . . 265 6.16.21. EXCEPTION-STATUS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266 6.16.22. EXP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268 6.16.23. EXP10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 269 6.16.24. FACTORIAL. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270 6.16.25. FRACTION-PART . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 271 6.16.26. HIGHEST-ALGEBRAIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 272 6.16.27. INTEGER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273 6.16.28. INTEGER-OF-DATE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274 6.16.29. INTEGER-OF-DAY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 275 6.16.30. INTEGER-PART . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 276 6.16.31. LENGTH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 277 6.16.32. LENGTH-AN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 278 6.16.33. LOCALE-COMPARE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279 6.16.34. LOCALE-DATE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 280 6.16.35. LOCALE-TIME . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 281 6.16.36. LOCALE-TIME-FROM-SECONDS . . . . . . . . . . . . . . . . . . . . 282 6.16.37. LOG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 283 6.16.38. LOG10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284 6.16.39. LOWER-CASE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 285 6.16.40. LOWEST-ALGEBRAIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286 6.16.41. MAX. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 287 6.16.42. MEAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288 6.16.43. MEDIAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289 6.16.44. MIDRANGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290 6.16.45. MIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291 6.16.46. MOD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 292 6.16.47. MODULE-CALLER-ID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293 6.16.48. MODULE-DATE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294 6.16.49. MODULE-FORMATTED-DATE . . . . . . . . . . . . . . . . . . . . . . 295 6.16.50. MODULE-ID. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296 6.16.55. MODULE-PATH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297 6.16.52. MODULE-SOURCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 298 6.16.53. MODULE-TIME . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 299 6.16.54. MONETARY-DECIMAL-POINT . . . . . . . . . . . . . . . . . . . . . . 300 6.16.55. MONETARY-THOUSANDS-SEPARATOR . . . . . . . . . . . . 301 6.16.56. NUMERIC-DECIMAL-POINT . . . . . . . . . . . . . . . . . . . . . . . . 302 6.16.57. NUMERIC-THOUSANDS-SEPARATOR . . . . . . . . . . . . . . 303 6.16.58. NUMVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 304 6.16.59. NUMVAL-C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 305 6.16.60. NUMVAL-F . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 306 6.16.61. ORD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 307 6.16.62. ORD-MAX . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308 3 June 2014 Contents vi GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 6.16.63. ORD-MIN. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309 6.16.64. PI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310 6.16.65. PRESENT-VALUE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311 6.16.66. RANDOM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312 6.16.67. RANGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314 6.16.68. REM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 315 6.16.69. REVERSE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 316 6.16.70. SECONDS-FROM-FORMATTED-TIME . . . . . . . . . . . . . . 317 6.16.71. SECONDS-PAST-MIDNIGHT. . . . . . . . . . . . . . . . . . . . . . . . . 318 6.16.72. SIGN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 319 6.16.73. SIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320 6.16.74. SQRT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 321 6.16.75. STANDARD-DEVIATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322 6.16.76. STORED-CHAR-LENGTH. . . . . . . . . . . . . . . . . . . . . . . . . . . . 323 6.16.77. SUBSTITUTE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324 6.16.78. SUBSTITUTE-CASE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325 6.16.79. SUM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326 6.16.80. TAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327 6.16.81. TEST-DATE-YYYYMMDD . . . . . . . . . . . . . . . . . . . . . . . . . . . 328 6.16.82. TEST-DAY-YYYYDDD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329 6.16.83. TEST-NUMVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330 6.16.84. TEST-NUMVAL-C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331 6.16.85. TEST-NUMVAL-F . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332 6.16.86. TRIM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333 6.16.87. UPPER-CASE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334 6.16.88. VARIANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335 6.16.89. WHEN-COMPILED. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336 6.16.90. YEAR-TO-YYYY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 337 6.17. GNU COBOL Statements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 338 6.17.1. ACCEPT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 338 6.17.1.1. ACCEPT FROM CONSOLE . . . . . . . . . . . . . . . . . . . . . . 338 6.17.1.2. ACCEPT FROM COMMAND-LINE. . . . . . . . . . . . . . . 339 6.17.1.3. ACCEPT FROM ENVIRONMENT . . . . . . . . . . . . . . . . 341 6.17.1.4. ACCEPT screen-data-item . . . . . . . . . . . . . . . . . . . . . . . . . 342 6.17.1.5. ACCEPT FROM DATE/TIME . . . . . . . . . . . . . . . . . . . . 347 6.17.1.6. ACCEPT FROM Screen-Info . . . . . . . . . . . . . . . . . . . . . . 348 6.17.1.7. ACCEPT FROM Runtime-Info . . . . . . . . . . . . . . . . . . . . 349 6.17.2. ADD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350 6.17.2.1. ADD TO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350 6.17.2.2. ADD GIVING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 352 6.17.2.3. ADD CORRESPONDING . . . . . . . . . . . . . . . . . . . . . . . . . 354 6.17.3. ALLOCATE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 356 6.17.4. ALTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 358 6.17.5. CALL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 359 6.17.6. CANCEL. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 363 6.17.7. CLOSE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 364 6.17.8. COMMIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365 6.17.9. COMPUTE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 366 Contents 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide vii 6.17.10. CONTINUE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 368 6.17.11. DELETE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 369 6.17.12. DISPLAY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 370 6.17.12.1. DISPLAY UPON device . . . . . . . . . . . . . . . . . . . . . . . . . . 370 6.17.12.2. DISPLAY UPON COMMAND-LINE . . . . . . . . . . . . . 372 6.17.12.3. DISPLAY UPON ENVIRONMENT-NAME . . . . . . . 373 6.17.12.4. DISPLAY screen-data-item . . . . . . . . . . . . . . . . . . . . . . . 374 6.17.13. DIVIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 376 6.17.13.1. DIVIDE INTO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 376 6.17.13.2. DIVIDE INTO GIVING . . . . . . . . . . . . . . . . . . . . . . . . . . 378 6.17.13.3. DIVIDE BY GIVING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 380 6.17.14. ENTRY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 382 6.17.15. EVALUATE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 383 6.17.16. EXIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 387 6.17.17. FREE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 390 6.17.18. GENERATE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 391 6.17.19. GOBACK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 393 6.17.20. GO TO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 394 6.17.20.1. Simple GO TO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 394 6.17.20.2. GO TO DEPENDING ON. . . . . . . . . . . . . . . . . . . . . . . . 395 6.17.21. IF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 397 6.17.22. INITIALIZE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 399 6.17.23. INITIATE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 404 6.17.24. INSPECT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 405 6.17.25. MERGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 411 6.17.26. MOVE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 414 6.17.26.1. Simple MOVE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 414 6.17.26.2. MOVE CORRESPONDING . . . . . . . . . . . . . . . . . . . . . . 415 6.17.27. MULTIPLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 416 6.17.27.1. MULTIPLY BY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 416 6.17.27.2. MULTIPLY GIVING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 418 6.17.28. OPEN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 420 6.17.29. PERFORM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 422 6.17.29.1. Procedural PERFORM . . . . . . . . . . . . . . . . . . . . . . . . . . . 422 6.17.29.2. Inline PERFORM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 424 6.17.29.3. VARYING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 425 6.17.30. READ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428 6.17.30.1. Sequential READ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 428 6.17.30.2. Random READ. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 430 6.17.31. READY TRACE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 433 6.17.32. RELEASE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 434 6.17.33. RESET TRACE. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 435 6.17.34. RETURN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 436 6.17.35. REWRITE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 437 6.17.36. ROLLBACK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 439 6.17.37. SEARCH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 440 6.17.38. SEARCH ALL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 442 6.17.39. SET. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 445 3 June 2014 Contents viii GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 6.17.39.1. SET ENVIRONMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . 445 6.17.39.2. SET Program-Pointer. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 446 6.17.39.3. SET ADDRESS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 447 6.17.39.4. SET Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 448 6.17.39.5. SET UP/DOWN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 449 6.17.39.6. SET Condition Name . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 450 6.17.39.7. SET Switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 451 6.17.39.8. SET ATTRIBUTE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 452 6.17.40. SORT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 453 6.17.40.1. File-Based SORT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 453 6.17.40.2. Table SORT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 457 6.17.41. START . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 459 6.17.42. STOP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 461 6.17.43. STRING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 463 6.17.44. SUBTRACT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 465 6.17.44.1. SUBTRACT FROM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 465 6.17.44.2. SUBTRACT GIVING . . . . . . . . . . . . . . . . . . . . . . . . . . . . 467 6.17.44.3. SUBTRACT CORRESPONDING . . . . . . . . . . . . . . . . 469 6.17.45. SUPPRESS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 471 6.17.46. TERMINATE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 472 6.17.47. TRANSFORM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 473 6.17.48. UNLOCK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 474 6.17.49. UNSTRING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 475 6.17.50. WRITE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 479 7. Report Writer Usage Notes . . . . . . . . . . . . . . . . . . 483 7.1. RWCS Lexicon . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 483 7.2. The Anatomy of a Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 484 7.3. The Anatomy of a Report Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 485 7.4. How RWCS Builds Report Pages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 486 7.5. Control Hierarchy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 488 7.6. An Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 490 7.6.1. Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 490 7.6.2. Program . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 492 7.6.3. Generated Report Pages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 497 7.7. Control Hierarchy (Revisited) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 503 7.8. Turning PHYSICAL Page Formatting Into LOGICAL Formatting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 506 Contents 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide ix 8. Interfacing With The OS . . . . . . . . . . . . . . . . . . . . . 509 8.1. Compiling Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 509 8.1.1. cobc - The GNU COBOL Compiler . . . . . . . . . . . . . . . . . . . . . . 509 8.1.2. Compilation Time Environment Variables . . . . . . . . . . . . . . . . 514 8.1.3. Locating Copybooks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 515 8.1.4. Compiler Configuration Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 516 8.2. Running Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 519 8.2.1. Direct Execution. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 519 8.2.2. Executing Dynamically-Loadable Libraries . . . . . . . . . . . . . . . 520 8.2.2.1. cobcrun - Command-line Execution . . . . . . . . . . . . . . . . . 520 8.2.2.2. Dynamically Loaded Subprograms . . . . . . . . . . . . . . . . . . 521 8.2.3. Run Time Environment Variables . . . . . . . . . . . . . . . . . . . . . . . . 522 8.2.4. Program Arguments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 524 8.3. Built-In System Subroutines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 525 8.3.1. C$CALLEDBY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 526 8.3.2. C$CHDIR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 526 8.3.3. C$COPY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 527 8.3.4. C$DELETE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 527 8.3.5. C$FILEINFO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 527 8.3.6. C$GETPID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 528 8.3.7. C$JUSTIFY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 528 8.3.8. C$MAKEDIR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 529 8.3.9. C$NARG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 529 8.3.10. C$PARAMSIZE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 530 8.3.11. C$PRINTABLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 530 8.3.12. C$SLEEP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 530 8.3.13. C$TOLOWER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 531 8.3.14. C$TOUPPER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 531 8.3.15. CBL AND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 531 8.3.16. CBL CHANGE DIR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 532 8.3.17. CBL CHECK FILE EXIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . 532 8.3.18. CBL CLOSE FILE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 533 8.3.19. CBL COPY FILE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 533 8.3.20. CBL CREATE DIR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 534 8.3.21. CBL CREATE FILE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 534 8.3.22. CBL DELETE DIR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 535 8.3.23. CBL DELETE FILE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 535 8.3.24. CBL EQ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 536 8.3.25. CBL ERROR PROC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 536 8.3.26. CBL EXIT PROC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 538 8.3.27. CBL FLUSH FILE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 540 8.3.28. CBL GET CSR POS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 540 8.3.29. CBL GET CURRENT DIR . . . . . . . . . . . . . . . . . . . . . . . . . . . . 541 8.3.30. CBL GET SCR SIZE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 541 8.3.31. CBL IMP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 542 8.3.32. CBL NIMP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 543 8.3.33. CBL NOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 543 3 June 2014 Contents x GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 8.3.34. CBL NOT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 544 8.3.35. CBL OC NANOSLEEP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 544 8.3.36. CBL OPEN FILE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 545 8.3.37. CBL OR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 545 8.3.38. CBL READ FILE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 546 8.3.39. CBL RENAME FILE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 546 8.3.40. CBL TOLOWER. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 547 8.3.41. CBL TOUPPER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 547 8.3.42. CBL WRITE FILE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 548 8.3.43. CBL XOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 548 8.3.44. SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 549 8.3.45. X"91" . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 550 8.3.46. X"E4" . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 551 8.3.47. X"E5" . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 551 8.3.48. X"F4" . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 551 8.3.49. X"F5" . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 552 8.4. Binary Truncation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 552 9. Sub-Programming . . . . . . . . . . . . . . . . . . . . . . . . . . . . 557 9.1. Subprogram Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 557 9.2. Independent vs Contained vs Nested Subprograms . . . . . . . . . . . . 557 9.3. Alternate Entry Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 559 9.4. Dynamic vs Static Subprograms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 559 9.5. Subprogram Execution Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 561 9.5.1. Subroutine Execution Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 561 9.5.2. User-Defined Function Execution Flow . . . . . . . . . . . . . . . . . . . 563 9.6. Sharing Data Between Calling and Called Programs . . . . . . . . . . . 565 9.5.1. Subprogram Arguments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 565 9.6.1.1. Calling Program Considerations . . . . . . . . . . . . . . . . . . . . . 565 9.6.1.2. Called Program Considerations. . . . . . . . . . . . . . . . . . . . . . 566 9.6.2. GLOBAL Data Items . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 567 9.6.3. EXTERNAL Data Items . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 567 9.7. Recursive Subprograms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 568 9.8. Combining GNU COBOL and C Programs . . . . . . . . . . . . . . . . . . . . 571 9.9.1. GNU COBOL Run-Time Library Requirements . . . . . . . . . . 571 9.9.2. String Allocation Differences Between GNU COBOL and C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 572 9.9.3. Matching C Data Types with GNU COBOL USAGEs . . . . 573 9.9.4. GNU COBOL Main Programs CALLing C Subprograms . . 574 9.9.5. C Main Programs Calling GNU COBOL Subprograms . . . 575 Contents 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide xi 10. Programming Style Suggestions . . . . . . . . . . . . 579 10.1. Marking Changes in Programs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 579 10.2. Data Item Coding and Naming Conventions . . . . . . . . . . . . . . . . . 579 10.3. Table Subscripting versus Table Indexing . . . . . . . . . . . . . . . . . . . . 582 10.4. Copybook Naming Conventions and Usage . . . . . . . . . . . . . . . . . . . 584 10.5. PROCEDURE DIVISION Sections Versus Paragraphs . . . . . . . 585 10.6. COMPUTE Versus ADD-SUBTRACT-MULTIPLY-DIVIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 586 Appendix A - Glossary of Terms . . . . . . . . . . . . . . . 589 Appendix B - Reserved Word List . . . . . . . . . . . . . 599 Appendix C - GNU Free Documentation License . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 603 Appendix D - Summary of Document Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 611 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 615 3 June 2014 Contents GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 1 1. Introduction This document describes the syntax, semantics and usage of the COBOL programming lan- guage as implemented by the current version of GNU COBOL, formerly known as Open- COBOL. The principal developers of GNU COBOL are Keisuke Nishida and Roger While. They may be contacted through the GNU COBOL website – sourceforge.net/projects/open-cobol. This document was intended to serve as a full-function reference and user’s guide suitable for both those readers learning COBOL for the first time as well as those already familiar with some dialect of the COBOL language. 1.1. Additional Reference Sources For those wishing to learn COBOL for the first time, I can strongly recommend the following resources. If you like to hold a book in your hands, I strongly recommend "Murach’s Structured COBOL", by Mike Murach, Anne Prince and Raul Menendez (2000) - ISBN 9781890774059. Mike Murach and his various writing partners have been writing outstanding COBOL text- books for decades, and this text is no exception. It’s an excellent book for those familiar with the concepts of programming in other languages, but unfamiliar with COBOL. Would you prefer a web-based tutorial? Try the University of Limerick (Ireland) COBOL web site - ‘http://www.csis.ul.ie/cobol/’. 1.2. Introducing COBOL If you already know a programming language, and that language isn’t COBOL, chances are that language is Java, C or C++. You will find COBOL a much different programming language than those; sometimes those differences are a good thing and sometimes they aren’t. The thing to remember about COBOL is this — it was designed to solve business problems. COBOL, first introduced to the programming public in 1959, was the very first programming language to become standardized (in 1960). This meant that a standard-compliant COBOL program written on computer "A" made by company "B" would be able to be compiled and executed on computer "X" made by company "Y" with very few, if any, changes. This may not seem like such a big deal today, but it was a radical departure from all programming languages that came before it and even many that came after it. The name COBOL actually says it all — COBOL is an acronym that stands for "(CO)mmon (B)usiness (O)riented (L)anguage". Note the fact that the word "common" comes before all others. The word "business" is a close second. Therein lies the key to COBOL’s success. 3 June 2014 Chapter 1 - Introduction 2 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 1.2.1. Why YOU Should Learn COBOL Despite statements from industry "insiders", the COBOL programming language is not dead, even though newer and so-called "modern" languages like Java, C#, .NET, Ruby on Rails and so on appear to have become the languages of choice in the Information Technology world. These languages have become popular because they address the following desired requirements for "modern" programming: 1. They conform to the principles of Object-Oriented Programming (OOP). This is desired for one major reason — it facilitates "code reusability", thus improving the productivity of programmers by allowing them to re-use previously written (and debugged) code in new applications. For one reason or another, COBOL is perceived as being weak in this regard. It isn’t (especially today), as we’ll see in the next section, but perception is important. 2. Those languages aren’t limited to mainframe computers, as COBOL is perceived to be. Some, like .NET and Ruby, aren’t even available on mainframes. The "modern" pro- gramming languages were designed and intended for use on the full variety of computer platforms, from shirt-pocket computers (i.e. smartphones) up to the most massive of supercomputers. There are several excellent commercially available COBOL implementations available for non-mainframe systems (Micro Focus COBOL, AccuCOBOL, NetCOBOL and Elas- tic COBOL, just to name a few), including Windows and UNIX/Linux systems. These aren’t cheap, however. 3. Universities love the "Modern" languages. In the U.S., 73% of colleges lack even one COBOL course on their curricula. COBOL, it appears, is no longer "cool" enough for students to fill a classroom. Just because COBOL doesn’t traditionally support objects, classes, and the like doesn’t mean that its "procedural" approach to computing isn’t valuable — after all, it runs 70% of the worlds business transactions, and does so: • Using programs that, for the most part, are much more self-documenting than would be the case with any other programming language. • Effortlessly providing arithmetic accuracy to 31 digits, with performance approaching that of well-written assembly-language programs. Don’t think this isn’t critically im- portant to banks, investment houses and any business interested in tracking revenues, expenses and profits (duh - like ALL of them). • Integrating well with non-COBOL infrastructures such as XML, SOA, MQ, almost any DBMS, Transaction Processing platforms, Queue-Management facilities and other programming languages. • By running on almost as many different computing platforms as Java can. You can’t run COBOL programs in your smartphone, but desktops, workstations, midframes/servers, mainframes and supercomputers are all fair game. Chapter 1 - Introduction 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 3 Today’s IT managers and business leaders are faced with a challenging dilemma — how do you maintain the enourmous COBOL codebase that is still running their businesses when academia has all but abandoned the language they need their people to use to keep the wheels rolling? The problem is compounded by the fact that those programmers that are skilled in COBOL are retiring and taking their knowledge with them. In some markets, this appears to be having an inflationary effect on the cost of resources (COBOL programmers) whose supply is becoming smaller and smaller. The pressure to update applications to make use of more up-to-date graphical user interfaces is also perceived as a reason to abandon COBOL in favor of GUI-friendly languages such as Java. Businesses are addressing the COBOL challenge in different ways: 1. By undertaking so-called "modernization projects", where existing applications are either rewritten in "modern" languages or replaced outright with purchased packages. Most of these businesses are using such activities as an excuse to abandon "expensive" mainframes in favor of (presumably) less-expensive "open systems" (midframe/server) solutions. Many times these businesses are finding the cost of the system/networking engineering, operational management and monitoring and risk management (i.e. disaster recovery) infrastructures necessary to support truly mission-critical applications to be so high that the "less-expensive" solution really isn’t; in these cases the mainframe may remain the best option, thus leaving COBOL in play and businesses seeking another solution for at least part of their application base. 2. Training their own COBOL programmers. Since colleges, universities and technical schools have lost interest in doing so, many businesses have undertaken the task of "growing their own" new crop of COBOL programmers. Fear of being pidgeon-holed into a niche technology is a factor inhibiting many of today’s programmers from will- ingly volunteering for such training. 3. By moving the user-interface onto the desktop; such efforts involve running modern- language front-end clients on user desktops (or laptops or smartphones, etc.) with COBOL programs provideing server functionality on mainframe or midframe platforms, providing all the database and file "heavy lifting" on the back-end. Solutions like this provide users with the user-interfaces they want/need while still leveraging COBOL’s strengths on (possibly) downsized legacy mainframe or midframe systems. It’s probably a true that an IT professional can no longer afford to allow COBOL to be the only wrench in their toolbox, but with a massive codebase still in production now and for the foreseeable future, adding COBOL to a multi-lingual curriculum vitae (CV) and/or resume (yes — they ARE different) is not a bad thing at all. Knowing COBOL as well as the language du-jour will make you the smartest person in the room when the discussion of migrating the current "legacy" environment to a "modern" implementation comes around. You’ll find COBOL an easy language to learn and a FAR EASIER language to master than many of the "modern" languages. 3 June 2014 Chapter 1 - Introduction 4 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide The whole reason you’re reading this is that you’ve discovered GNU COBOL — another implementation of COBOL in addition to those mentioned earlier. The distinguishing characteristic of GNU COBOL versus those others is that GNU COBOL is open-source and therefore FREE. It is community-enhanced and community-supported. Later in this document (see [So What is GNU COBOL?], page 5), you’ll begin to learn more about this COBOL implementation’s capabilities. 1.2.2. Programmer Productivity Throughout the history of computer programming, the search for new ways to improve of the productivity of programmers has been a major consideration. Other than hobbyists, programming is an activity performed for money, and businesses abhor spending anything more than is absolutely necessary; even government agencies try to spend as little money on projects as is absolutely necessary. The amount of programming necessary to accomplish a given task — including rework needed by any errors found during testing (testing is sometimes jokingly defined as: "that time during which an application is actually in production, allowing users to discover the problems") is the measure of programmer productivity. Anything that reduces that effort will therefore reduce the time spent in such activities therefore reducing the expense of same. When the expense of programming is reduced, programmer productivity is increased. Sometimes the quest for improved programmer productivity (and therefore reduced pro- gramming expense) has taken the form of introducing new features in programming lan- guages, or even new languages altogether. Sometimes it has resulted in new ways of using the existing languages. While many technological and procedural developments have made evolutionary improve- ments to programmer productivity, each of the following three events has been responsible for revolutionary improvements: • The development of so-called "higher-level" programming languages that enable a pro- grammer to specify in a single statement of the language an action that would have required many more separate statements in a prior programming language. The stan- dardization of such languages, making them usable on a wide variety of computers and operating systems, was a key aspect of this development. COBOL was a pioneering de- velopment in this area, being a direct descendant of the very first higher-level language (FLOW-MATIC, developed by US Naval Lieutenant Grace Hopper) and the first to become standardized. • The establishment of programming techniques that make programs easier to read and therefore easier to understand. Not only do such techniques reduce the amount of rework necessary simply to make a program work as designed, but they also reduce the amount of time a programmer needs to study an existing program in order how to best adapt it to changing business requirements. The foremost development in this area was structured programming. Introduced in the late 1970s, this approach to programming spawned new programming languages (PASCAL, ALGOL, PL/1 and so forth) designed around it. With the ANSI85 standard, COBOL embraced the principles espoused Chapter 1 - Introduction 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 5 by structured programming mavens as well as any of the languages designed strictly around it. • The establishment of programming techniques AND the introduction of programming language capabilities to facilitate the reusability of program code. Anything that sup- ports code reusability can have a profound impact to the amount of time it takes to In recent develop new applications or to make significant changes to existing ones. years, object-oriented programming (OOP) has been the industry "poster child" for code reusability. By enabling program logic and the data structures that logic manip- ulates to be encapsulated into easily stored and retrieved (and therefore "reusable") modules called classes, the object-oriented languages such as Java, C++ and C# have become the favorites of academia. Since students are being trained in these languages and only these, by and large, it’s no surprise that — today — object-oriented program- ming languages are the darlings of the industry. The reality is, however, that good programmers have been practicing code reusability for more than a half-century. Up until recently, COBOL programmers have had some of the best code reusability tools available — they’ve been doing it with copybooks and subprograms rather than classes, methods and attributes but the net results have been similar. With the COBOL2002 standard and proposed COBOL20xx standard, the COBOL programming language has become just as "object-oriented" as the "mod- ern" languages, while preserving the ability to support, modify, compile and execute "legacy" COBOL programs as well. While GNU COBOL supports few of the OOP programming constructs defined by the COBOL2002 and COBOL20xx standards, it supports every aspect of the ANSI85 standard and therefore fully meets the needs of points #1 and #2, above. With it’s supported feature set (see [So What is GNU COBOL?], page 5), it provides significant programmer productivity capabilities. 1.3. So What is GNU COBOL? GNU COBOL is an open source COBOL compiler and runtime environment, written using the C programming language. GNU COBOL is typically distributed in source-code form, and must then be built for your computer’s operating system using the system’s C compiler and loader. While originally developed for the UNIX and Linux operating systems, GNU COBOL has also been successfully built for OSX computers or Windows computers utilizing the UNIX-emulation features of such tools as Cygwin and MinGW. The MinGW approach is a personal favorite with the author of this manual because it creates a GNU COBOL compiler and runtime library that require only a single MinGW DLL to be available for the GNU COBOL compiler, runtime library and user programs. That DLL is freely distributable under the terms of the GNU General Public License. A MinGW build of GNU COBOL fits easily on and runs from a 128MB flash drive with no need to install any software onto the Windows computer that will be using it. Some functionality of the language, dealing with the sharing of files between concurrently executing GNU COBOL programs and record locking on certain types of files, is sacrificed however as the underlying 3 June 2014 Chapter 1 - Introduction 6 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide operating system routines needed to implement them aren’t available to Windows and aren’t provided by MinGW. GNU COBOL has also been built as a truly native Windows application utilizing Mi- crosoft’s freely-downloadable Visual Studio Express package to provide the C compiler and linker/loader. This approach does not lend itself well to a "portable" distribution. The GNU COBOL compiler generates C code from your COBOL programs; that C code is then automatically compiled and linked using your system’s C compiler (typically, but not limited to, "gcc"). GNU COBOL fully supports much of the ANSI85 standard for COBOL (the only ma- jor exclusion is the Communications Module) and also supports some of the components of the COBOL2002 standard, such as the "SCREEN SECTION" (see [SCREEN SECTION], page 115), table-based "SORT" (see [Table SORT], page 457) and user-defined functions. 1.3.1. Language Reserved Words COBOL programs consist of a sequence of words and symbols. Words, which consist of sequences of letters (upper- and/or lower-case), digits, dashes ("-") and/or underscores (" ") may have a pre-defined, specific, meaning to the compiler or may be invented by the programmer for his/her purposes. The GNU COBOL language specification defines over 700 ’Reserved Words’ — words to which the compiler assigns a special meaning. Programmers may use a reserved word as part of a word they are creating themselves, but may not create their own word as an exact duplicate (without regard to case) of a COBOL reserved word. See [Appendix B - Reserved Word List], page 599, for a complete list of GNU COBOL reserved words. 1.3.2. User-Defined Words When you write GNU COBOL programs, you’ll need to create a variety of words to represent various aspects of the program, the program’s data and the external environment in which the program will run. This will include internal names by which data files will be referenced, data item names and names of executable logic procedures. User-defined words may be composed from the characters "A" through "Z" (upper- and/or lower-case), "0" through "9", dash ("-") and underscore (" "). User-defined words may neither start nor end with hyphen or underscore characters. Other programming language provide the programmer with a similar capability of creat- ing their own words (names) for parts of a program; COBOL is somewhat unusual when compared to other languages in that user-defined words may start with a digit. With the exception of logic procedure names, which may consist entirely of nothing but digits, user-defined words must contain at least one letter. Chapter 1 - Introduction 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 7 1.3.3. Case Insensitivity All COBOL implementations allow the use of both upper and lowercase letters in program coding. GNU COBOL is completely insensitive to the case used when writing reserved words or user-defined names. Thus, "AAAAA", "aaaaa", "Aaaaa" and "AaAaA" are all the same word as far as GNU COBOL is concerned. The only time the case used does matter is within quoted character strings, where character values will be exactly as coded. By convention throughout this document, COBOL reserved words will be shown entirely in UPPERCASE while those words that were created by a programmer will be represented by tokens in mixed or lower case. This isn’t a bad practice to use in actual programs, as it leads to programs where it is much easier to distinguish reserved words from user-defined ones! 1.3.4. Readability of Programs The most vociferous critics of COBOL frequently focus on the wordiness of the language, often citing the case of a so-called "Hello World" program as the "proof" that COBOL is so much more tedious to program in than more "modern" languages. This tedium is cited as such a significant impact to programmer productivity that, in their opinions, COBOL can’t go away quickly enough. Here are two different "Hello World" applications — one written in Java and the second in GNU COBOL. First, the Java version: Class HelloWorld { public static void main(String[] args) { System.out.println("Hello World!"); } } And here is the same program, written in GNU COBOL: IDENTIFICATION DIVISION. PROGRAM-ID. HelloWorld. PROCEDURE DIVISION. DISPLAY "Hello World!". Both of the above programs could have been written on a single line, if desired, and both languages allow a programmer to use (or not use) indentation as they see fit to improve program readability. Sounds like a tie so far. Let’s look at how much more "wordy" COBOL is than Java. Count the characters in the two programs. The Java program has 95 (not counting carriage returns and any indenta- tion). The COBOL program has 89 (again, not counting carriage returns and indentation)! Technically, it could have been only 65 because the "IDENTIFICATION DIVISION." header 3 June 2014 Chapter 1 - Introduction 8 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide is actually optional. Clearly, "Hello World" doesn’t look any more concise in Java than it does in COBOL. Let’s look at a different problem. Surely a program that asks a user to input a positive integer, generates the sum of all positive integers from 1 to that number and then prints the result will be MUCH shorter and MUCH easier to understand when coded in Java than in COBOL, right? You can be the judge. First, the Java version: import java.util.Scanner; public class sumofintegers { public static void main(String[] arg) { System.out.println("Enter a positive integer"); Scanner scan=new Scanner(System.in); int n=scan.nextInt(); int sum=0; for (int i=1;i<=n;i++) { sum+=i; } System.out.println("The sum is "+sum); } } And now for the COBOL version: IDENTIFICATION DIVISION. PROGRAM-ID. SumOfIntegers. DATA DIVISION. WORKING-STORAGE SECTION. BINARY-LONG. 01 n 01 i BINARY-LONG. 01 sum BINARY-LONG VALUE 0. PROCEDURE DIVISION. DISPLAY "Enter a positive integer" ACCEPT n PERFORM VARYING i FROM 1 BY 1 UNTIL i > n ADD i TO sum END-PERFORM DISPLAY "The sum is " sum. My familiarity with COBOL may be prejudicing my opinion, but it doesn’t appear to me In case you’re interested in that the Java code is any simpler than the COBOL code. character counts, the Java code comes in at 278 (not counting indentation characters). The COBOL code is 298 (274 without the "IDENTIFICATION DIVISION." header). Despite what you’ve seen here, the more complex the programming logic being implemented, the more concise the Java code will appear to be, even compared to 2002-standard COBOL. Chapter 1 - Introduction 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 9 That conciseness comes with a price though — program code readability. Java (or C or C++ or C#) programs are generally intelligible only to trained programmers. COBOL programs can, however, be quite understandable by non-programmers. This is actually a side-effect of the "wordiness" of the language, where COBOL statements use natural English words to describe their actions. This inherent readability has come in handy many times throughout my career when I’ve had to learn obscure business (or legal) processes by reading the COBOL program code that supports them. The "modern" languages, like Java, also have their own "boilerplate" infrastructure overhead that must be coded in order to write the logic that is necessary in the program. the "public static void main(String[] arg)" and "import Take java.util.Scanner;" statements. The critics tend to forget about this when they criticize COBOL for it’s structural "overhead". example for When it first was developed, COBOL’s easily-readable syntax made it profoundly different from anything that had been seen before. For the first time, it was possible to specify logic in a manner that was — at least to some extent — comprehensible even to non-programmers. Take for example, the following code written in FORTRAN — a language developed only a year before COBOL: EXT = PRICE * IQTY INVTOT = INVTOT + EXT With its original limitation on the length of variable names (one- to six-character names comprised of a letter followed by up to five letters and/or digits), it’s implicit rule that variable were automatically created as real (floating-point) unless their name started with a letter in the range I-N, and its use of algebraic notation to express actions being taken, FORTRAN wasn’t a particularly readable language, even for programmers. Compare this with the equivalent COBOL code: MULTIPLY price BY quantity GIVING extended-amount ADD extended-amount TO invoice-total Clearly, even a non-programmer could at least conceptually understand what was going on! Over time, languages like FORTRAN evolved more robust variable names, and COBOL introduced a more formula-based syntactical capability for arithmetic operations, but FOR- TRAN was never as readable as COBOL. Because of its inherent readability, I would MUCH rather be handed an assignment to make significant changes to a COBOL program about which I know nothing than to be asked to do the same with a C, C++, C# or Java program. Those that argue that it is too boring / wasteful / time-consuming / insulting (pick one) to have to code a COBOL program "from scratch" are clearly ignorant of the following facts: • Many systems have program-development tools available to ease the task of coding programs; those tools that concentrate on COBOL are capable of providing templates for much of the "overhead" verbiage of any program. . . 3 June 2014 Chapter 1 - Introduction 10 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide • Good programmers have — for decades — maintained their own skeleton "template" programs for a variety of program types; simply load a template into a text editor and you’ve got a good start to the program. . . • Legend has it that there’s actually only been ONE program ever written in COBOL, and all programs ever "written" thereafter were simply derivatives of that one. Although this is clearly intended as a (probably) bad joke, it is nevertheless close to the very simple truth that many programers"reuse" existing COBOL programs when creating new ones. There’s certainly nothing preventing this from happening with programs written in other languages, but it does seem to happen more in COBOL shops. It’s ironic that "code reusability" is one of the arguments used to justify the existence of the "modern" languages. 1.3.5. Divisions Organize Programs COBOL programs are structured into four major areas of coding, each with its own purpose. These four areas are known as divisions. Each division may consist of a variety of sections and each section consists of one or more paragraphs. A paragraph consists of sentences, each of which consists of one or more statements. This hierarchical structure of program components standardizes the composition of all COBOL programs. Much of this manual describes the various divisions, sections, para- graphs and statements that may comprise any COBOL program. 1.3.6. Copybooks A ’Copybook ’ is a segment of program code that may be utilized by multiple programs simply by having those programs use the "COPY" statement (see [COPY], page 40) to import that code. This code may define files, data structures or procedural code. Today’s current programming languages have a statement (usually, this statement is named "import", "include" or "#include") that performs this same function. What makes the COBOL copybook feature different than the "include" facility in newer languages, however, is the fact that the "COPY" statement can edit the imported source code as it is being copied. This capability makes copybook libraries extremely valuable to making code reusable. 1.3.7. Structured Data A contiguous area of storage within the memory space of a program that may be refer- enced, by name, in a COBOL program is referred to as a ’Data Item’. Other programming languages use the term variable, property or attribute to describe the same thing. COBOL introduced the concept of structured data. The principle of structured data in COBOL is based on the idea of being able to group related and contiguously-allocated data items together into a single aggregate data item, called a ’Group Item’. For example, a 35-character ’Employee-Name’ group item might consist of a 20-character ’Last-Name’ followed by a 14-character ’First-Name’ and a 1-character ’Middle-Initial’. Chapter 1 - Introduction 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 11 A data item that isn’t itself formed from other data items is referred to in COBOL as an ’Elementary Item’. In the previous example, ’Last-Name’, ’First-Name’ and ’Middle-Initial’ are all elementary items. 1.3.8. Files One of COBOLs strengths is the wide variety of data files it is capable of accessing. GNU COBOL programs, like those created with other COBOL implementations, need to have the structure of any files they will be reading and/or writing described to them. The highest- level characteristic of a file’s structure is defined by specifying the organization of the file, as follows: "ORGANIZATION LINE SEQUENTIAL" These are files with the simplest of all internal structures. Their contents are structured simply as a series of identically- or differently-sized data records, each terminated by a special end-of-record delimiter character. An ASCII line- feed character (hexadecimal 0A) is the end-of-record delimiter character used by any UNIX or pseudo-UNIX (MinGW, Cygwin, OSX) GNU COBOL build. A truly native Windows build would use a carriage-return, line-feed (hexadecimal 0D0A) sequence. Records must be read from or written to these files in a purely sequential manner. The only way to read (or write) record number 100 would be to have read (or written) records number 1 thru 99 first. When the file is written to by a GNU COBOL program, the delimiter sequence will be automatically appended to each data record as it is written to the file. A "WRITE" (see [WRITE], page 479) to this type of file will be done as if a "BEFORE ADVANCING 1 LINE" clause were specified on the "WRITE", if no "ADVANCING" clause is coded. When the file is read, the GNU COBOL runtime system will strip the trailing delimiter sequence from each record. The data will be padded (on the right) with spaces if the data just read is shorter than the area described for data records in the program. If the data is too long, it will be truncated and the excess will be lost. These files should not be defined to contain any exact binary data fields because the contents of those fields could inadvertently have the end-of-record sequence as part of their values — this would confuse the runtime system when reading the file, and it would interpret that value as an actual end-of-record sequence. "LINE ADVANCING" These are files with an internal structure similar to that of a line sequential file. These files are defined (without an explicit "ORGANIZATION" specification) using the "LINE ADVANCING" clause on their "SELECT" statement (see [SELECT], page 73). 3 June 2014 Chapter 1 - Introduction 12 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide When this kind of file is written to by a GNU COBOL program, an end-of- record delimiter sequence will be automatically added to each data record as it is written to the file. A "WRITE" to this type of file will be done as if an "AFTER ADVANCING 1 LINE" clause were specified on the "WRITE", if no "ADVANCING" clause is coded. Like line sequential files, these files should not be defined to contain any exact binary data fields because the contents of those fields could inadvertently have the end-of-record sequence as part of their values — this would confuse the runtime system when reading the file, and it would interpret that value as an actual end-of-record sequence. "ORGANIZATION SEQUENTIAL" These files also have a simple internal structure. Their contents are structured simply as an arbitrarily-long sequence of data characters. This sequence of characters will be treated as a series of fixed-length records simply by logically splitting the sequence of characters up into fixed-length segments, each as long as the maximum record size defined in the program. There are no special end- of-record delimiter characters in the file and when the file is written to by a GNU COBOL program, no delimiter sequence is appended to the data. Records in this type of file are all the same physical length, except possibly for the very last record in the file, which may be shorter than the others. If variable-length logical records are defined to the program, the space occupied by each physical record in the file will occupy the space described by the longest record description in the program. So, if a file contains 1275 characters of data, and a program defines the struc- ture of that file as containing 100-character records, then the file contents will consist of twelve (12) 100-character records with a final record containing only 75 characters. It would appear that it should be possible to locate and process any record in the file directly simply by calculating its starting character position based upon the program-defined record size. Even so, however, records must be still be read or written to these files in a purely sequential manner. The only way to read (or write) record number 100 would be to have read (or written) records number 1 thru 99 first. When the file is read, the data is transferred into the program exactly as it exists in the file. In the event that a short record is read as the very last record, that record will be padded (to the right) with spaces. Care must be taken that programs reading such a file describe records whose length is exactly the same as that used by the program that created the file. For example, the following shows the contents of a "SEQUENTIAL" file created by a program that wrote five 6-character records to it. The "A", "B", . . . values reflect the records that were written to the file: Chapter 1 - Introduction 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 13 ‘AAAAAABBBBBBCCCCCCDDDDDDEEEEEE’ Now, assume that another program reads this file, but describes 10-character records rather than 6. Here are the records that program will read: ‘AAAAAABBBB’ ‘BBCCCCCCDD’ ‘DDDDEEEEEE’ There may be times where this is exactly what you were looking for. More often than not, however, this is not desirable behavior. Suggestion: use a copybook to describe the record layouts of any file; this guarantees that multiple programs accessing that file will "see" the same record sizes and layouts by coding a "COPY" statement (see [COPY], page 40) to import the record layout(s) rather than hand-coding them. These files can contain exact binary data fields. This is possible because — since there is no character sequence that constitutes an end-of-record delimiter — the contents of record fields are irrelevant to the reading process. "ORGANIZATION RELATIVE" The contents of these files consist of a series of fixed-length data records prefixed with a four-byte record header. The record header contains the length of the data, in bytes. The byte-count does not include the four-byte record header. Records in this type of file are all the same physical length. If variable-length logical records are defined to the program, the space occupied by each physical record in the file will occupy the maximum possible space, and the logical record length field will contaoin the number of bytes of data in the record that are actually in use. This file organization was defined to accommodate either sequential or random processing. With a "RELATIVE" file, it is possible to read or write record 100 directly, without having to have first read or written records 1-99. The GNU COBOL runtime system uses the program-defined maximum record size to calculate a relative byte position in the file where the record header and data begin, and then transfers the necessary data to or from the program. When the file is written by a GNU COBOL program, no delimiter sequence is appended to the data, but a record-length field is added to the beginning of each physical record. When the file is read, the data is transferred into the program exactly as it exists in the file. Care must be taken that programs reading such a file describe records whose length is exactly the same as that used by the programs that created the file. It won’t end well if the GNU COBOL runtime library interprets a four-byte 3 June 2014 Chapter 1 - Introduction 14 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide ASCII character string as a record length when it transfers data from the file into the program! Suggestion: use a copybook to describe the record layouts of any file; this guarantees that multiple programs accessing that file will "see" the same record sizes and layouts by coding a "COPY" statement (see [COPY], page 40) to import the record layout(s) rather than hand-coding them. These files can contain exact binary data fields. The contents of record fields are irrelevant to the reading process as there is no end-of-record delimiter. "ORGANIZATION INDEXED" This is the most advanced file structure available to GNU COBOL programs. It’s not possible to describe the physical structure of such files because that structure will vary depending upon which advanced file-management facility was included into the GNU COBOL build you will be using (Berkeley Database [BDB], VBISAM, etc.). We will — instead — discuss the logical structure of the file. There will be multiple structures stored for an "INDEXED" file. The first will be a data component, which may be thought of as being similar to the internal structure of a relative file. Data records may not, however, be directly accessed by their record number as would be the case with a relative file, nor may they be processed sequentially by their physical sequence in the file. The remaining structures will be one or more index components. An index component is a data structure that (somehow) enables the contents of a field, called a primary key, within each data record (a customer number, an employee number, a product code, a name, etc.) to be converted to a record number so that the data record for any given primary key value can be directly read, written and/or deleted. Additionally, the index data structure is defined in such a manner as to allow the file to be processed sequentially, record-by-record, in ascending sequence of the primary key field values. Whether this index structure exists as a binary-searchable tree structure (btree), an elaborate hash structure or something else is pretty much irrelevant to the programmer — the behavior of the structure will be as it was just described. The actual mechanism used will depend upon the advanced file-management package was included into your GNU COBOL implementation when it was built. The runtime system will not allow two records to be written to an indexed file with the same primary key value. The capability exists for an additional field to be defined as what is known as an alternate key. Alternate key fields behave just like primary keys, allowing both direct and sequential access to record data based upon the alternate key field values, with one exception. That exception is the fact that alternate keys may be allowed to have duplicate values, depending upon how the alternate key field is described to the GNU COBOL compiler. Chapter 1 - Introduction 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 15 There may be any number of alternate keys, but each key field comes with a disk space penalty as well as an execution time penalty. As the number of alternate key fields increases, it will take longer and longer to write and/or modify records in the file. These files can contain exact binary data fields. The contents of record fields are irrelevant to the reading process as there is no end-of-record delimiter. All files are initially described to a GNU COBOL program using a "SELECT" statement (see [SELECT], page 73). In addition to defining a name by which the file will be referenced within the program, the "SELECT" statement will specify the name and path by which the file will be known to the operating system along with its organization, locking and sharing attributes. A file description in the "FILE SECTION" (see [FILE SECTION], page 93) will define the structure of records within the file, including whether or not variable-length records are possible and — if so — what the minimum and maximum length might be. In addition, the file description entry can specify file I/O block sizes. 1.3.9. Table Handling Other programming languages have arrays, COBOL has tables. They’re basically the same thing. There are two special statements that exist in the COBOL language — "SEARCH" (see [SEARCH], page 440) and "SEARCH ALL" (see [SEARCH ALL], page 442) — that make finding data in a table easy. The first can search a table sequentially, stopping only when either a table entry matching one of any number of search conditions is found, or when all table entries have been checked against the search criteria and none matched any of those criteria. The second can perform an extremely fast search against a table sorted by and searched against a key field contained in each table entry. The algorithm used for such a search is a binary search (also known as a half-interval search). This algorithm ensures that only a small number of entries in the table need to be checked in order to find a desired entry or to determine that the desired entry doesn’t exist in the table. The larger the table, the more effective this search becomes. For example, a binary search of a table containing 32,768 entries will be able to locate a particular entry or determine the entry doesn’t exist by looking at no more than fifteen (15) entries! The algorithm is explained in detail in the documentation of the "SEARCH ALL" statement (see [SEARCH ALL], page 442). Finally, COBOL has the ability to perform in-place sorts of the data that is found in a table. 1.3.10. Sorting and Merging Data The COBOL language includes a powerful "SORT" statement (see [SORT], page 453) that can sort large amounts of data according to arbitrarily complex key structures. This data may originate from within the program or may be contained in one or more external files. 3 June 2014 Chapter 1 - Introduction 16 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide The sorted data may be written automatically to one or more output files or may be processed, record-by-record in the sorted sequence. A companion statement — "MERGE" (see [MERGE], page 411) — can combine the contents of multiple files together, provided those files are all pre-sorted in a similar manner according to the same key structure. The resulting output will consist of the contents of all of the input files, merged together and sequenced according to the common key structure(s). The output generated by a "MERGE" statement may be written automatically to one or more output files or may be processed internally by the program. A special form of the "SORT" statement also exists just to sort the data that resides in a table. This is particularly useful if you wish to use "SEARCH ALL" against the table. 1.3.11. String Manipulation Features There have been programming languages designed specifically for the processing of text strings, and there have been programming languages designed for the sole purpose of per- forming high-powered numerical computations. Most programming languages fall some- where in the middle. COBOL is no exception, although it does include some very powerful string manipulation capabilities; GNU COBOL actually has even more string-manipulation capabilities than many other COBOL implementations. The following summarizes GNU COBOL’s string- processing capabilities: Concatenate two or more strings: • "CONCATENATE" intrinsic function (see [CONCATENATE], page 254). • "STRING" statement (see [STRING], page 463). Conversion of a numeric time or date to a formatted character string: • "LOCALE-TIME" intrinsic function (see [LOCALE-TIME], page 281). • "LOCALE-DATE" intrinsic function (see [LOCALE-DATE], page 280). Convert a binary value to its corresponding character in the program’s characterset: • "CHAR" intrinsic function (see [CHAR], page 252). Add 1 to argument before invoking the function; the description of the "CHAR" intrinsic function presents a technique utilizing the "MOVE" statement that will accomplish the same thing without the need of adding 1 to the numeric argument value first. Convert a character string to lower-case: • "LOWER-CASE" intrinsic function (see [LOWER-CASE], page 285). • "C$TOLOWER" built-in system subroutine (see [C$TOLOWER], page 531). Chapter 1 - Introduction 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 17 • "CBL_TOLOWER" built-in system subroutine (see [CBL TOLOWER], page 547). Convert a character string to upper-case: • "UPPER-CASE" intrinsic function (see [UPPER-CASE], page 334). • "C$TOUPPER" built-in system subroutine (see [C$TOUPPER], page 531). • "CBL_TOUPPER" built-in system subroutine (see [CBL TOUPPER], page 547). Convert a character string to only printable characters: • "C$PRINTABLE" built-in system subroutine (see [C$PRINTABLE], page 530). Convert a character to its numeric value in the program’s characterset: • "ORD" intrinsic function (see [ORD], page 307). Subtract 1 from the result; the descrip- tion of the "ORD" intrinsic function presents a technique utilizing the "MOVE" statement that will accomplish the same thing without the need of adding 1 to the numeric ar- gument value first. Count occurrences of substrings in a larger string: • "INSPECT" statement (see [INSPECT], page 405) with the "TALLYING" clause. Decode a formatted numeric string back to a numeric value: • "NUMVAL" intrinsic function (see [NUMVAL], page 304). • "NUMVAL-C" intrinsic function (see [NUMVAL-C], page 305). Determine the length of a string or data-item capable of storing strings: • "LENGTH" intrinsic function (see [LENGTH], page 277). • "BYTE-LENGTH" intrinsic function (see [BYTE-LENGTH], page 251). Extract a substring from a string based on its starting character position and length: • Use of a reference modifier on the string field - See [Reference Modifiers], page 213. Format a numeric item for output, including thousands-separators ("," in the USA), cur- rency symbols ("$" in the USA), decimal points, credit/Debit Symbols, Leading Or Trailing Sign Characters: • "MOVE" statement (see [MOVE], page 414) with picture-symbol editing applied to the receiving field: Justification (left, right or centered) of a string field: 3 June 2014 Chapter 1 - Introduction 18 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide • "C$JUSTIFY" built-in system subroutine (see [C$JUSTIFY], page 528). Monoalphabetic substitution of one or more characters in a string with different characters: • "INSPECT" statement (see [INSPECT], page 405) with the "CONVERTING". • "TRANSFORM" statement (see [TRANSFORM], page 473). • "SUBSTITUTE" intrinsic function (see [SUBSTITUTE], page 324). • "SUBSTITUTE-CASE" intrinsic function (see [SUBSTITUTE-CASE], page 325). Parse a string, breaking it up into substrings based upon one or more delimiting character sequences1: • "UNSTRING" statement (see [UNSTRING], page 475). Removal of leading or trailing spaces from a string: • "TRIM" intrinsic function (see [TRIM], page 333). Substitution of a single substring with another of the same length, based upon the sub- strings starting character position and length: • "MOVE" statement (see [MOVE], page 414) with a reference modifier on the "receiving" field (see [Reference Modifiers], page 213). Substitution of one or more substrings in a string with replacement substrings of the same length, regardless of where they occur: • "INSPECT" statement (see [INSPECT], page 405) with a "REPLACING" clause. • "SUBSTITUTE" intrinsic function (see [SUBSTITUTE], page 324). • "SUBSTITUTE-CASE" intrinsic function (see [SUBSTITUTE-CASE], page 325). Substitution of one or more substrings in a string with replacement substrings of a poten- tially different length, regardless of where they occur: • "SUBSTITUTE" intrinsic function (see [SUBSTITUTE], page 324). • "SUBSTITUTE-CASE" intrinsic function (see [SUBSTITUTE-CASE], page 325). 1.3.12. Screen Formatting Features The COBOL2002 standard formalizes extensions to the COBOL language that allow for the definition and processing of text-based screens, as is a typical function on mainframe and 1 These delimiters may be single characters, multiple-character strings or multiple consecutive occurrences of either Chapter 1 - Introduction 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 19 midframe computers as well as on many point-of-sale (i.e. "cash register") systems. GNU COBOL implements virtually all the screen-handling features described by COBOL2002. These features allow fields to be displayed at specific row/column positions, various colors and video attributes to be assigned to screen fields and the pressing of specific function keys (F1, F2, . . . ) to be detectable. All of this takes place through the auspices of the "SCREEN SECTION" (see [SCREEN SECTION], page 115) and special formats of the "ACCEPT" state- ment (see [ACCEPT], page 338) and the "DISPLAY" statement (see [DISPLAY], page 370). The COBOL2002 standard, and therefore GNU COBOL, only covers textual user interface (TUI) screens (those comprised of ASCII characters presented using a variety of visual attributes) and not the more-advanced graphical user interface (GUI) screen design and processing capabilities built into most modern operating systems. There are subroutine- based packages available that can do full GUI presentation — most of which may be called by GNU COBOL programs, with a moderate research time investment (Tcl/Tk, for example) — but none are currently included with GNU COBOL. 1.3.12.1. A Sample Screen A Sample Screen Produced by a GNU COBOL Program: The above screen was produced by the GNU COBOL Interactive Compiler, or GCic. See the "GNU COBOL Sample Programs (gnucobsp)" documentation for the source code to this program. 3 June 2014 Chapter 1 - Introduction 20 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide Screens are defined in the screen section of the data division. Once defined, screens are used at run-time via the "ACCEPT" and "DISPLAY" statements. 1.3.12.2. Color Palette and Video Attributes GNU COBOL supports the following visual attribute specifications in the "SCREEN SECTION" (see [SCREEN SECTION], page 115): Color Eight (8) different colors may be specified for both the background (screen) and foreground (text) color of any row/column position on the screen. Colors are specified by number, although a copybook supplied with all GNU COBOL distributions ("screenio.cpy") defines COB-COLOR-xxxxxx names for the var- ious colors so they may be specified as a more meaningful name rather than a number. The eight colors, by number, with the constant nams defined in screenio.cpy, are as follows: 0. Black: COB-COLOR-BLACK 1. Blue: COB-COLOR-BLUE 2. Green: COB-COLOR-GREEN 3. Cyan (Turquoise): COB-COLOR-CYAN 4. Red: COB-COLOR-RED 5. Magenta: COB-COLOR-MAGENTA 6. Yellow: COB-COLOR-YELLOW 7. White: COB-COLOR-WHITE Text Brightness There are three possible brightness levels supported for text — lowlight (dim), normal and highlight (bright). Not all GNU COBOL implementations will support all three (some treat lowlight the same as normal). The deciding factor as to whether two or three levels are supported lies with the version of the "curses" package that is being used. This is a utility screen-IO package that is included into the GNU COBOL run-time library when the GNU COBOL software is built. As a general rule of thumb, Windows implementations support two levels while Unix ones support all three. Blinking This too is a video feature that is dependent upon the "curses" package built into your version of GNU COBOL. If blinking is enabled in that package, text displayed in fields defined in the screen section as being blinking will endlessly Chapter 1 - Introduction 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 21 cycle between the brightest possible setting (highlight) and an "invisible" set- ting where the text color matches that of the field background color. A Windows build, which generally uses the "pcurses" package, will uses a brighter-than- normal background color to signify "blinking". Reverse Video This video attribute simply swaps the foreground and background colors and display options. Field Outlining It is possible, if supported by the "curses" package being used, to draw borders on the top, left and/or bottom edges of a field. Secure Input If desired, screen fields used as input fields may defined as "secure" fields, where each input character (regardless of what was actually typed) will appear as an asterisk (*) character. The actual character whose key was pressed will still be stored into the field in the program, however. This is very useful for password or account number fields. Prompt Character Input fields may have any character used as a fill character. These fill characters provide a visual indication of the size of the input field, and will automatically be transformed into spaces when the input field is propcessed by the program. If no such character is defined for an input field, an underscore (" ") will be assumed. The following is a sample of the GNU COBOL color Palette, showing all possible combina- tions of the various video attributes. This example was prepared on a Macintosh running OSX Mavericks (10.9). Blinking works — the screen snapshot shows things in mid blink, when the text and background colors are momentarily the same. Unfortunately, only two screen intensities are available (like Windows, the "lowlight" setting is the same as the default). 3 June 2014 Chapter 1 - Introduction 22 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide The GNU COBOL Color Palette and Video Options:: The rows of each block are numbered with the background color while columns are numbered with the foreground color. See Section “Colors” in GNU COBOL Sample Programs, for a source and cross-reference listing of the program (Colors.cbl) that produced the above screen. 1.3.13. Report Writer Features GNU COBOL includes an implementation of the Report Writer Control System, or RWCS. This is a standardized, optional add-on feature to the COBOL language which automates much of the mechanics involved in the generation of printed reports by: 1. Controlling the pagination of reports, including: A. The automatic production of a one-time notice on the first page of the report (report heading). B. The production of zero or more header lines at the top of every page of the report (page heading). C. The production of zero or more footer lines at the bottom of every page of the report (page footing). Chapter 1 - Introduction 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 23 D. The automatic numbering of printed pages. E. The formatting of those report lines that make up the main body of the report (detail). F. Full awareness of where the "pen" is about to "write" on the current page, auto- matically forcing an eject to a new page, along with the automatic generation of a page footer to close the old page and/or a page header to begin the new one. G. The production of a one-time notice at the end of the last page of a report (report footing). 2. Performing special reporting actions based upon the fact that the data being used to generate the report has been sorted according to one or more key fields: A. Automatically suppressing the presentation of one or more fields of data from the detail group when the value(s) of the field(s) duplicate those of the previously generated detail group. Fields such as these are referred to as group-indicate fields. B. Automatically causing suppressed detail group-indicate fields to re-appear should a detail group be printed on a new page. C. Recognizing when control fields on the report — fields tied to those that were used as "SORT" statement (see [SORT], page 453) keys — have changed. This is known as a control break. The RWCS can automatically perform the following reporting actions when a control break occurs: • Producing a footer, known as a control footing after the detail lines that shared the same old value for the control field. • Producing a header, known as a control heading before the detail lines that share the same new value for the control field. 3. Perform data summarization, as follows: A. Automatically generating subtotals in control and/or report footings, summarizing values of any fields in the detail group. B. Automatically generating crossfoot totals in detail groups. These would be sums of two or more values presented in the detail group. The "REPORT SECTION" (see [REPORT SECTION], page 107) documentation explores the description of reports and the "PROCEDURE DIVISION" (see [PROCEDURE DIVISION], page 201) chapter documents the various language statements that actually produce re- ports. Before reading these, you might find it helpful to read [Report Writer Usage Notes], page 483, which is dedicated to putting the pieces together for you. 1.3.14. Data Initialization There are three ways in which data division data gets initialized. 1. When a program or subprogram is first executed, much of the data in it’s data division will be initialized as follows: 3 June 2014 Chapter 1 - Introduction 24 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide • Alphanumeric and alphabetic (i.e. text) data items will be initialized to "SPACES". • Numeric data items will be initialized to a value of "ZERO". • Data items with an explicit "VALUE" (see [VALUE], page 197) clause in their definition will be initialized to that specific value. The various sections of the data division each have their own rules as to when the actions described above will occur — consult the documentation on those sections for additional information. These default initialization rules can vary quite substantially from one COBOL imple- mentation to another. For example, it is quite common for data division storage to be initialized to all binary zeros except for those data items where "VALUE" clauses are present. Take care when working with applications originally developed for an- other COBOL implementation to ensure that GNU COBOL’s default initialization rules won’t prove disruptive. 2. A programmer may use the "INITIALIZE" statement (see [INITIALIZE], page 399) to intitialize any group or elementary data item at any time. This statement provides far more initialization options than just the simple rules stated above. 3. When the "ALLOCATE" statement (see [ALLOCATE], page 356) statement is used to allocate a data item or to simply allocate an area of storage of a size specified on the "ALLOCATE", that allocation may occur with or without initialization, as per the programmer’s needs. 1.3.15. Syntax Diagram Conventions Syntax of the GNU COBOL language will be described in special "syntax diagrams" using the following syntactical-description techniques: MANDATORY-RESERVED-WORD ~~~~~~~~~~~~~~~~~~~~~~~ Reserved words of the COBOL language will appear in UPPERCASE. When they appear underlined, as this one is, they are required reserved words. OPTIONAL-RESERVED-WORD When reserved words appear without underlining, as this one is, they are op- tional; such reserved words are available in the language syntax merely to im- prove readability — their presence or absence has no effect upon the program. ABBREVIATION ~~~~ When only a portion of a reserved word is underlined, it indicates that the word may either be coded in its full form or may be abbreviated to the portion that is underlined. Chapter 1 - Introduction 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 25 substitutable-items Generic terms representing user-defined substitutable items will be shown en- tirely in lowercase in syntax diagrams. When such items are referenced in text, they will appear as . Complex-Syntax-Clause Items appearing in Mixed Case within a syntax diagram represent complex clauses of other syntax elements that may appear in that position. Some COBOL syntax gets quite complicated, and using a convention such as this significantly reduces the complexity of a syntax diagram. When such items are referenced in text, they will appear as <>. [ ] | { xxxxxx } { yyyyyy } { zzzzzz } | xxxxxx | | yyyyyy | | zzzzzz | ... Square bracket metacharacters on syntax diagrams document language syntax that is optional. The [] characters themselves should not be coded. If a syntax diagram contains "a [b] c", the "a" and "c" syntax elements are mandatory but the "b" element is optional. Vertical bar metacharacters on syntax diagrams document simple choices. The | character itself should not be coded. If a syntax diagram contains "a|b|c", exactly one of the items "a", "b" or "c" must be selected. A vertical list of items, bounded by multiple brace characters, is another way of signifying a choice between a series of items where exactly one item must be selected. This form is used to show choices when one or more of the selections is more complex than just a single word, or when there are too many choices to present horizontally with "|" metacharacters. A vertical list of items, bounded by multiple vertical bar characters, signifies a choice between a series of items where one or more of the choices could be selected. The ... metacharacter sequence signifies that the syntax element immediately preceeding it may be repeated. The ... sequence itself should not be coded. If a syntax diagram contains "a b... c", syntax element "a" must be followed 3 June 2014 Chapter 1 - Introduction GNU COBOL 2.1 [23NOV2013] Programmer’s Guide by at least one "b" element (possibly more) and the entire sequence must be terminated by a "c" syntax element. 26 { } The braces ({}) metacharacters may be used to group a sequence of syntax ele- ments together so that they may be treated as a single entity. The {} characters themselves should not be coded. These are typically used in combination with the "|" or "..." metacharacters. $*^()-+=:"’<,>./ Any of these characters appearing within a syntax diagram are to be interpreted literally, and are characters that must be coded — where allowed — in the statement whose format is being described. Note that a "." character is a literal character that must be coded on a statement whereas a "..." symbol is the metacharacter sequence described above. 1.3.16. Format of Program Source Lines Prior to the COBOL2002 standard, source statements in COBOL programs were structured around 80-column punched cards. This means that each source line in a COBOL program consisted of five different "areas", defined by their column number(s). As of the COBOL2002 standard, a second mode now exists for COBOL source code state- ments — in this mode of operation, COBOL statements may each be up to 255 characters long, with no specific requirements as to what should appear in which columns. Of course, in keeping with the long-standing COBOL tradition of maintaining backwards compatibility with older standards, programmers (and, of course, compliant COBOL com- pilers) are capable of working in either mode. It is even possible to switch back and forth in the same program. The terms ’Fixed Format Mode’ and ’Free Format Mode’ are used to refer to these two modes of source code formatting. The GNU COBOL compiler (cobc) supports both of these source line format modes, de- faulting to Fixed Format Mode lacking any other information. The compiler can be instructed to operate in either mode in any of the following four ways: 1. Using a compiler option switch — use the "-fixed" switch to start in Fixed Format Mode (remember that this is the default) or the "-free" switch to start in Free Format Mode. 2. You may use the "SOURCEFORMAT AS FIXED" and "SOURCEFORMAT AS FREE" clauses of the ">>SET" CDF directive (see [>>SET], page 49) within your source code to switch to Fixed or Free Format Mode, respectively. 3. You may use the ">>FORMAT IS FIXED" and "FORMAT IS FREE" clauses of the ">>DEFINE" CDF directive (see [>>DEFINE], page 45) within your source code to switch to Fixed or Free Format Mode, respectively. Chapter 1 - Introduction 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 27 4. You may use the ">>SOURCE" CDF directive (see [>>SOURCE], page 50) to switch to Free Format Mode (">>SOURCE FORMAT IS FREE") or Fixed Format Mode (">>SOURCE FORMAT IS FIXED". Using methods 2-4 above, you may switch back and forth between the two formats at will. The last three options above are all equivalent; all three are supported by GNU COBOL so that source code compatibility may be maintained with a wide variety of other COBOL implementations. With all three, if the compiler is currently in Fixed Format Mode, the ">>" must begin in column 8 or beyond, provided no part of the directive extends past column 72. If the compiler is currently in Free Format Mode, the ">>" may appear in any column, provided no part of the directive extends past column 255. Depending upon which source format mode the compiler is in, you will need to follow various rules for the format mode currently in effect. These rules are presented in the upcoming paragraphs. The following discussion presents the various components of every GNU COBOL source line record when the compiler is operating in Fixed Format Mode. Remember that this is the default mode for the GNU COBOL compiler. 1-6 - Sequence Number Area Historically, back in the days when punched-cards were used to submit COBOL program source to a COBOL compiler, this part of a COBOL statement was reserved for a six-digit sequence number. While the contents of this area are ignored by COBOL compilers, it existed so that a program actually punched on 80-character cards could — if the card deck were dropped on the floor — be run through a card sorter machine and restored to it’s proper sequence. Of course, this isn’t necessary today; if truth be told, it hasn’t been necessary for a long time. See [Marking Changes in Programs], page 579, for discussion of a valuable use to which the sequence number area may be put today. 7 - Indicator Area Column 7 serves as an indicator in which one of five possible values will appear — space, "D" (or "d"), "-" (dash), "/" or "*". The meanings of these characters are as follows: space D/d No special meaning — this is the normal character that will appear in this area. 3 June 2014 Chapter 1 - Introduction 28 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide * / - The line contains a valid GNU COBOL statement that is normally treated as a comment unless the program is being compiled in de- bugging mode. The line is a comment. The line is a comment that will also force a page eject in the com- pilation listing. While GNU COBOL will honor such a line as a comment, it will not form-feed any generated listing. The line is a continuation of the previous line. These are needed only when an alphanumeric literal (quoted character string), re- served word or user-defined word are being split across lines. 8-11 - Area "A" Language DIVISION, SECTION and paragraph section headers must begin in Area A, as must the level numbers 01, 77 in data description entries and the "FD" and "SD" file and SORT description headers. 12-72 - Area "B" All other COBOL programming language components are coded in these columns. 73-80 - Program Name Area This is another obsolete area of COBOL statements. This part of every state- ment also hails back to the day when programs were punched on cards; it was expected that the name of the program (or at least the first 8 characters of it) would be punched here so that — if a dropped COBOL source deck contained more than one program — that handy card sorter machine could be used to first separate the cards by program name and then sort them by sequence number. Today’s COBOL compilers (including GNU COBOL) simply ignore anything past column 72. See [Marking Changes in Programs], page 579, for discussion of a valuable use to which the program name area may be put today. Chapter 1 - Introduction 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 29 1.3.17. Program Structure (cid:11) (cid:10) Complete GNU COBOL Program Syntax (cid:8) (cid:9) [ IDENTIFICATION DIVISION. ] ~~~~~~~~~~~~~~~~~~~~~~~ PROGRAM-ID|FUNCTION-ID. name-1 [ Program-Options ] . ~~~~~~~~~~ ~~~~~~~~~~~ [ ENVIRONMENT DIVISION. ] ~~~~~~~~~~~ ~~~~~~~~ [ CONFIGURATION SECTION. ] ~~~~~~~~~~~~~ ~~~~~~~ [ SOURCE-COMPUTER. ~~~~~~~~~~~~~~~ [ OBJECT-COMPUTER. ~~~~~~~~~~~~~~~ [ REPOSITORY. ~~~~~~~~~~ [ SPECIAL-NAMES. ~~~~~~~~~~~~~ [ INPUT-OUTPUT SECTION. ] ~~~~~~~~~~~~ ~~~~~~~ [ FILE-CONTROL. ~~~~~~~~~~~~ [ I-O-CONTROL. ~~~~~~~~~~~ [ DATA DIVISION. ] ~~~~~~~~~~~~~ [ FILE SECTION. ~~~~~~~~~~~~ Compilation-Computer-Specification . ] Execution-Computer-Specification . ] Function-Specification... . ] Program-Configuration-Specification . ] General-File-Description... . ] File-Buffering-Specification... . ] . . . ] ] ] Detailed-File-Description... Subprogram-Argument-Description... . ] [ WORKING-STORAGE SECTION. Permanent-Data-Definition... ~~~~~~~~~~~~~~~ ~~~~~~~ [ LOCAL-STORAGE SECTION. ~~~~~~~~~~~~~ ~~~~~~~ Temporary-Data-Definition... [ LINKAGE SECTION. ~~~~~~~ ~~~~~~~ [ REPORT SECTION. ~~~~~~ ~~~~~~~ [ SCREEN SECTION. ~~~~~~ ~~~~~~~ PROCEDURE DIVISION [ { USING Subprogram-Argument... ~~~~~~~~~ ~~~~~~~~ Screen-Layout-Definition... Report-Description... . ] { ~~~~~ { CHAINING Main-Program-Argument... . ] } ] } } ~~~~~~~~ 3 June 2014 Chapter 1 - Introduction 30 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide [ DECLARATIVES. ] ~~~~~~~~~~~~ [ RETURNING identifier-1 ] . ~~~~~~~~~ [ Event-Handler-Routine... . [ END DECLARATIVES. ] ~~~ ~~~~~~~~~~~~ General-Program-Logic ] [ Nested-Subprogram... [ END PROGRAM|FUNCTION name-1 ] ] ~~~ ~~~~~~~ ~~~~~~~~ ———————————————————————————————————————— Each program consists of up to four ’Divisions’ (major groupings of sections, paragraphs and descriptive or procedural coding that all relate to a common purpose), named Identification, Environment, Data and Procedure. 1. Not all divisions are needed in every program, but they must be specified in the order shown when they are used. 2. The following points pertain to the identification division • The "IDENTIFICATION DIVISION." header is always optional. 3. The following points pertain to the environment division: • If both optional sections of this division are coded, they must be coded in the sequence shown. • Each of these sections paragraphs ("SOURCE-COMPUTER" and "OBJECT-COMPUTER", Each of these paragraphs serves a specific purpose. If no code is required for the purpose one of the paragraphs serves, the entire paragraph may be omitted. specific example). consists series for of of a • If none of the paragraphs within one of the sections are coded, the section header itself may be omitted. • The paragraphs within each section may only be coded in that section, but may be coded in any order. • If none of the sections within the environment division are coded, the "ENVIRONMENT DIVISION." header itself may be omitted. 4. The following points pertain to the data division: • The data division consists of six optional sections — when used, those sections must be coded in the order shown in the syntax diagram. • Each of these sections consists of code which serves a specific purpose. If no code is required for the purpose one of those sections serves, the entire section, including it’s header, may be omitted. Chapter 1 - Introduction 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 31 • If none of the sections within the data division are coded (a highly unlikely, but theoretically possible circumstance), the "DATA DIVISION." header itself may be omitted. 5. The following points pertain to the procedure division: • As with the other divisions, the procedure division may consist of sections and those sections may — in turn — consist of paragraphs. Unlike the other divisions, however, section and paragraph names are defined by the programmer, and there may not be any defined at all if the programmer so wishes. • Each Event-Handler-Routine will be a separate section devoted to trapping a par- ticular run-time event. If there are no such sections coded, the "DECLARATIVES." and "END DECLARATIVES." lines may be omitted. 6. A single file of COBOL source code may contain: • A portion of a program; these files are known as copybooks • A single program. In this case, the "END PROGRAM" or "END FUNCTION" statement is optional. • Multiple programs, separated from one another by "END PROGRAM" or "END FUNCTION" statements. The final program in such a source code file need not have an "END PROGRAM" or "END FUNCTION" statement. 7. Subprogram "B" may be nested inside program "A" by including program B’s source code at the end of program A’s procedure division without an intervening "END PROGRAM A." or "END FUNCTION A." statement. For now, that’s all that will be said about nesting. See [Independent vs Contained vs Nested Subprograms], page 557, for more information. 8. Regardless of how many programs comprise a single GNU COBOL source file, only a single output executable program will be generated from that source file when the file is compiled. 1.3.18. Comments The following information describes how comments may be imbedded into GNU COBOL program source to provide documentation. Comment Type Blank Lines Source Mode — Description FIXED — Blank lines may be inserted as desired. FREE — Blank lines may be inserted as desired. 3 June 2014 Chapter 1 - Introduction 32 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide Full-line comments Full-line comments with form-feed FIXED — An entire source line will be treated as a comment (and will be ignored by the compiler) by coding an asterisk ("*") in column seven (7). FREE — An entire source line will be treated as a comment (and will be ignored by the compiler) by coding the sequence "*>", starting in any column, as the first non-blank characters on the line. FIXED — An entire source line will be treated as a comment by coding a slash ("/") in column seven (7). Many COBOL compilers will also issue a form-feed in the program listing so that the "/" line is at the top of a new page. The GNU COBOL compiler does not support this form-feed behavior. The GNU COBOL Interactive Compiler, or GCic, does sup- port this form-feed behavior when it generates program source listings! See Section “GCic” in GNU COBOL Sample Pro- grams, for the source and cross-reference listing (produced by GCic) of this program — you can see the effect of "/" there. FREE — There is no Free Source Mode equivalent to "/". Partial-line comments FIXED — Any text following the character sequence "*>" on a source line will be treated as a comment. The "*" must appear in column seven (7) or beyond. Comments that may be treated as typi- cally for debug- ging purposes code, FREE — Any text following the character sequence "*>" on a source line will be treated as a comment. The "*" may appear in any column. FIXED — By coding a "D" in column 7 (upper- or lower-case), an otherwise valid GNU COBOL source line will be treated as a comment by the compiler. FREE — By specifying the character sequence ">>D" (upper- or lower-case) as the first non-blank characters on a source line, an otherwise valid GNU COBOL source line will be treated as a comment by the compiler. Debugging statements may be compiled either by specifying the "-fdebugging-line" switch on the GNU COBOL com- piler or by adding the "WITH DEBUGGING MODE" clause to the "SOURCE-COMPUTER" paragraph. 1.3.19. Literals Literals are constant values that will not change during the execution of a program. There are two fundamental types of literals — numeric and alphanumeric. Chapter 1 - Introduction 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 33 1.3.19.1. Numeric Literals A numeric literal is a numeric constant which may be used as an array subscript, as a value in arithmetic expressions, or in any procedural statement where a numeric value may be used. Numeric literals may take any of the following forms: • Integers such as 1, 56, 2192 or -54. • Non-integer fixed point values such as 1.317 or -2.95. • Floating-point values using "Enn" notation such as 9.92E25, representing 9.92 x 10^25 (10 raised to the 25th power) or 5.7E-14, representing 5.7 x 10^-14 (10 raised to the -14th power). Both the mantissa (the number before the E) and the exponent (the number after the E) may be explicitly specified as positive (with a +), negative (with a -) or unsigned (and therefore implicitly positive). A floating-point literal’s value must be within the range -1.7 x 10^308 to +1.7 x 10^308 with no more than 15 decimal digits of precision. • Hexadecimal numeric literals such as H"1F" (31 decimal), h’22’ (34 decimal) or H’DEAD’ (57005 decimal). The H character may either be upper- or lower-case and either single quote (’) or double-quote (") characters may be used in a hexadecimal literal, provided both aren’t used in the same literal. Hexadecimal numeric literals are limited to a maximum of sixteen hexadecimal digits (a 64-bit value). 1.3.19.2. Alphanumeric Literals An alphanumeric literal is a character string suitable for display on a computer screen, printing on a report, transmission through a communications connection or storage in al- phanumeric or alphabetic data items. An alphanumeric literal is not valid for use in arithmetic expressions unless it is first con- verted to it’s numeric computational equivalent; there are three numeric conversion intrin- sic functions built into GNU COBOL that can perform this conversion — "NUMVAL" (see [NUMVAL], page 304), "NUMVAL-C" (see [NUMVAL-C], page 305) and "NUMVAL-F" (see [NUMVAL-F], page 306). Alphanumeric literals may take any of the following forms: • A sequence of characters enclosed by a pair of single-quote (’) or double-quote (") characters constitutes a string literal. The double-quote character (") may be used as a data character within an apostrophe-delimited string literal, and an apostrophe may be used as a data character within a double-quote-delimited string literal. If an apostrophe character must be included as a data character within an apostrophe-delimited string literal, express that character as two consecutive apostrophes (”). If a double-quote character must be included as a data character within a double-quote-delimited string litaral, express that character as two consecutive double-quotes (""). • A literal formed according to the same rules as for a string literal (above), but prefixed with the letter "Z" (upper- or lower-case) constitutes a zero-delimited string literal. These literals differ from ordinary string literals in that they will be explicitly ter- 3 June 2014 Chapter 1 - Introduction 34 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide minated with a byte of hexadecimal value 00. These ’Zero-Delimited Alphanumeric Literals’ are easily passable to C subprograms, as this is the convention C uses to store character strings. • A ’Hexadecimal Alphanumeric Literal ’ such as X"4A4B4C" (4A4B4C16 = the ASCII string ’JKL’), x’20’ (an ASCII space) or X’30313233’ (3031323316 = the ASCII string ’0123’). The "X" character may either be upper- or lower-case and either single quote (’) or double-quote (") characters may be used. These hexadecimal alphanumeric lit- erals should always consist of an even number of hexadecimal digits, because each character is represented by eight bits worth of data (2 hex digits). Hexadecimal al- phanumeric literals may be of almost unlimited length. Alphanumeric literals too long to fit on a single line may be continued to the next line in one of two ways: 1. If you are using Fixed Format Mode, the alphanumeric literal can be run right up to and including column 72. The literal may then be continued on the next line anywhere after column 11 by coding another quote or apostrophe (whichever was used to begin the literal originally). The continuation line must also have a hyphen (-) coded in the indicator area (column 7). Here is an example (the scale is just for column number reference): 1 2 3 4 5 6 7 1234567890123456789012345678901234567890123456789012345678901234567890123 01 LONG-LITERAL-VALUE-DEMO - - - PIC X(60) VALUE "This is a long l "ong literal that " must be continu "ed.". 2. Regardless of whether the compiler is operating in Fixed or Free Format Mode, GNU COBOL allows alphanumeric literals to be broken up into separate fragments. These fragments have their own beginning and ending quote/apostrophe characters and are "glued together" at compilation time using "&" characters. No continuation indicator is needed. Here’s an example: 1 2 3 4 5 6 7 1234567890123456789012345678901234567890123456789012345678901234567890123 01 LONG-LITERAL-VALUE-DEMO PIC X(60) VALUE "This is a" & " long literal that must " & "be continued.". If your program is using Free Format Mode, there’s less need to continue long alphanumeric literals because statements may be as long as 255 characters. Numeric literals may be split across lines just as alphanumeric literals are, using either of the above techniques and both reserved and user-defined words can be split across lines too (using the first technique). The continuation of numeric literals and user-defined/reserved words is provided merely to provide compatibility with older COBOL versions and pro- grams, but should not be used with new programs — it just makes for ugly-looking pro- grams. Chapter 1 - Introduction 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 35 1.3.19.3. Figurative Constants Figurative constants are reserved words that may be used as literals anywhere the figurative constant’s value could be interpreted as an arbitrarily long sequence of the characters in question. When a specific length is required, such as would be the case with an argument to a subprogram, a figurative constant may not be used. Thus, the following are valid uses of figurative constants: 05 FILLER ... PIC 9(10) VALUE ZEROS. MOVE SPACES TO Employee-Name But this is not: CALL "SUBPGM" USING SPACES The following are the GNU COBOL figurative constants and their respective equivalent values. "ZERO" "SPACE" "QUOTE" This figurative constant has a value of numeric 0 (zero). "ZEROS" and "ZEROES" are both synonyms of "ZERO". This figurative constant has a value of one or more space characters. "SPACES" is a synonym of "SPACE". This figurative constant has a value of one or more double-quote characters ("). "QUOTES" is a synonym of "QUOTE". "LOW-VALUE" This figurative constant has a value of one or more of whatever character oc- cupies the lowest position in the program’s collating sequence as defined in the "OBJECT-COMPUTER" (see [OBJECT-COMPUTER], page 58) paragraph or — if no such specification was made — in whatever default characterset the program is using (typically, this is the ASCII characterset). "LOW-VALUES" is a synonym of "LOW-VALUE". When the characterset in use is ASCII with no collating sequence modifications, the "LOW-VALUES" figurative constant value is the ASCII "NUL" character. Because charactersets can be redefined, however, you should not rely on this fact — use the "NULL" figurative constant instead. 3 June 2014 Chapter 1 - Introduction 36 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide "HIGH-VALUE" This figurative constant has a value of one or more of whatever character occu- pies the highest position in the program’s collating sequence as defined in the "OBJECT-COMPUTER" paragraph or — if no such specification was made — in whatever default characterset the program is using (typically, this is the ASCII characterset). "HIGH-VALUES" is a synonym of "HIGH-VALUE". "NULL" A character comprised entirely of zero-bits (regardless of the programs collating sequence). Programmers may create their own figurative constants via the "SYMBOLIC CHARACTERS" (see [Symbolic-Characters-Clause], page 71) clause of the "SPECIAL-NAMES" (see [SPECIAL- NAMES], page 62) paragraph. 1.3.20. Punctuation A comma (",") or a semicolon (";") may be inserted into a GNU COBOL program to improve readability at any spot where white space would be legal, except of course within alphanumeric literals (unless you actually mean for those characters to be part of the al- phanumeric literal’s value). These characters are always optional. The use of comma characters can cause confusion to a COBOL compiler if the "DECIMAL POINT IS COMMA" clause is used in the "SPECIAL-NAMES" (see [SPECIAL-NAMES], page 62) paragraph, as might be the case in Europe. The following statement, which calls a subroutine passing it two arguments (the numeric constants 1 and 2): CALL "SUBROUTINE" USING 1,2 Would — with "DECIMAL POINT IS COMMA" in effect — actually be interpreted as a sub- routine call with 1 argument (the non-integer numeric literal whose value is 1 and 2 tenths). For this reason, it is best to always follow a comma with a space. The period character (".") is used to terminate statements in the identification, environment and data divisions and sentences in the procedure division. Syntax diagrams describing code in the first three divisions will explicitly show where periods need to occur. The rules for where and when periods are needed in the procedure division are somewhat complicated. See [Use of Periods], page 227, for the details. 1.3.21. LENGTH OF (cid:11) (cid:10) LENGTH OF Syntax LENGTH OF numeric-literal-1 | identifier-1 ~~~~~~ (cid:8) (cid:9) Chapter 1 - Introduction 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 37 ———————————————————————————————————————— Alphanumeric literals and identifiers may optionally be prefixed with the "LENGTH OF" clause. The compile-time value generated by this clause will be the number of bytes in the alphanumeric literal or the defined size (in bytes) of the identifier. 1. The reserved word "OF" is optional and may be included, or not, at the discretion of the programmer. The presence or absence of this word has no effect upon the program. Here is an example. The following two GNU COBOL statements both display the same result (27): 01 Demo-Identifier ... PIC X(27). DISPLAY LENGTH OF "This is a LENGTH OF Example" DISPLAY LENGTH OF Demo-Identifier 2. The "LENGTH OF" clause on a literal or identifier reference may generally be used any- where a numeric literal might be specified, with the following exceptions: • As part of the "FROM" clause of a "WRITE" (see [WRITE], page 479) or "RELEASE" statement (see [RELEASE], page 434). • As part of the "TIMES" clause of a "PERFORM" statement (see [PERFORM], page 422). 1.3.22. Interfacing to Other Environments Through the "CALL" statement, COBOL programs may invoke other COBOL programs serving as subprograms. This is quite similar to cross-program linkage capabilities provided by other languages. In GNU COBOL’s case, the "CALL" facility is powerful enough to be tailored to the point where a GNU COBOL program can communicate with operating system, database management and run-time library APIs, even if they weren’t written in COBOL themselves. See [GNU COBOL Main Programs CALLing C Subprograms], page 574, for an example of how a GNU COBOL program could invoke a C-language subprogram, passing information back and forth between the two. The fact that GNU COBOL supports a full-featured two-way interface with C-language programs means that — even if you cannot access a library API directly — you could always do so via a small C "wrapper" program that is "CALL"ed by a GNU COBOL program. ———————————————————— End of Chapter 1 — Introduction 3 June 2014 Chapter 1 - Introduction GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 39 2. CDF - Compiler Directing Facility The Compiler Directing Facility, or CDF, is a means of controlling the compilation of GNU COBOL programs. CDF provides a mechanism for dynamically setting or resetting certain compiler switches, introducing new source code from one or more source code libraries, making dynamic source code modifications and conditionally processing or ignoring source statements altogether. This is accomplished via a series of special CDF statements and directives that will appear in the program source code. When the compiler is operating in Fixed Format Mode, all CDF statements must begin in column eight (8) or beyond. There are two types of supported CDF statements in GNU COBOL — Text Manipulation Statements and Compiler Directives. The CDF text manipulation statements "COPY" and "REPLACE" are used to introduce new code into programs either with or without changes, or may be used to modify existing statements already in the program. Text manipulation statements are always terminated with a period. CDF directives, denoted by the presence of a ">>" character sequence as part of the state- ment name itself, are used to influence the process of program compilation. Compiler directives are never terminated with a period. 3 June 2014 Chapter 2 - CDF - Compiler Directing Facility 40 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide CDF COPY Statement Syntax (cid:8) (cid:9) 2.1. COPY (cid:11) (cid:10) COPY copybook-name ~~~~ [ IN|OF library-name ] ~~ ~~ [ SUPPRESS PRINTING ] ~~~~~~~~ [ REPLACING { Phrase-Clause | String-Clause }... ] . ~~~~~~~~~ ———————————————————————————————————————— (cid:11) (cid:8) (cid:10) CDF COPY Phrase-Clause Syntax (cid:9) { ==pseudo-text-1== } BY { ==pseudo-text-2== } } { identifier-1 } { literal-1 } { word-1 } ~~ { identifier-2 } } { literal-2 { word-2 ———————————————————————————————————————— (cid:11) (cid:8) (cid:10) CDF COPY String-Clause Syntax (cid:9) [ LEADING|TRAILING ] ==partial-word-1== BY ==partial-word-2== ~~~~~~~ ~~~~~~~~ ~~ ———————————————————————————————————————— 1. "COPY" statements are used to import copybooks (see [Copybooks], page 10) into a program. 2. "COPY" statements may be used anywhere within a COBOL program where the code contained within the copybook would be syntactically valid. 3. The optional "SUPPRESS" clause (with or without the optional "PRINTING" reserved word) is valid syntactically but is non-functional. It is supported to facilitate compat- ibility with source code written for other versions of COBOL. 4. There is no difference between the use of the word "IN" and the word "OF" — use the one you prefer. 5. A period is absolutely mandatory at the end of every "COPY" statement, even if the statement occurs within the scope of another one where a period might appear dis- ruptive, such as within the scope of an "IF" (see [IF], page 397) statement. This Chapter 2 - CDF - Compiler Directing Facility 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 41 mandatory period at the end of the statement will not, however, affect the statement scope in which the "COPY" occurs. 6. Both and may be null. 7. All "COPY" statements are located and the contents of the corresponding copybooks inserted into the program source code before the actual compilation process begins. If a copybook contains a "COPY" statement, the copybook insertion process will be repeated to resolve the imbedded "COPY". This will continue until no unresolved "COPY" statements remain. At that point, actual program compilation will begin. 8. See [Locating Copybooks], page 515, for the specific rules on how copybooks are located by the compiler. 9. The optional "REPLACING" clause allows for one or more of either of the following kinds of text replacements to be made: <> Replacement of one or more complete reserved words, user-defined identi- fiers or literals; the following points apply to this option: • This option cannot be used to replace part of a word, identifier or literal. • Whatever preceeds the "BY" will be referred to here as the search string. • Single-item search strings can be specified by coding the "", "" or "" being replaced. • Multiple-item search strings can be specified using the "====" option. For example, to replace all occurrences of "UPON PRINTER", you would specify "==UPON PRINTER==". • The replacement string, which follows the "BY", may be specified using any of the four options. • If the replacement string is a multiple-item phrase or is to be deleted altogether, you must use the "====" option. If "" is null (in other words, the replacement text is specified as "===="), all encountered occurrences of the search string will be deleted. <> Using this, you may replace character sequences that occur at the beginning ("LEADING") or end ("TRAILING") of reserved or user-defined words. For example, to change all words of the form "0100-xxxxxx" to "020-xxxxxx", code "LEADING ==0100-== BY ==020-==". To simply remove all "0100-" prefixes from words, code "LEADING ==0100-== BY ====". 3 June 2014 Chapter 2 - CDF - Compiler Directing Facility 42 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 2.2. REPLACE (cid:11) (cid:10) CDF REPLACE Statement (Format 1) Syntax REPLACE [ ALSO ] { Phrase-Clause | String-Clause }... ~~~~~~~ ~~~~ . (cid:8) (cid:9) ———————————————————————————————————————— (cid:11) (cid:8) (cid:10) CDF REPLACE Statement (Format 2) Syntax (cid:9) REPLACE [ LAST ] OFF . ~~~~~~~ ~~~~ ~~~ ———————————————————————————————————————— (cid:11) (cid:8) (cid:10) CDF REPLACE Phrase-Clause Syntax (cid:9) { ==pseudo-text-1== } BY { ==pseudo-text-2 } ~~ ———————————————————————————————————————— (cid:11) (cid:8) (cid:10) CDF REPLACE String-Clause Syntax (cid:9) [ LEADING|TRAILING ] ==partial-word-1== BY ==partial-word-2== ~~~~~~~ ~~~~~~~~ ~~ ———————————————————————————————————————— 1. The "REPLACE" statement provides a mechanism for changing all or part of one or more GNU COBOL statements. 2. A period is absolutely mandatory at the end of every "REPLACE" statement (either format), even if the statement occurs within the scope of another one where a period might appear disruptive (such as within the scope of an "IF" (see [IF], page 397) state- ment; the period will not, however, affect the statement scope in which the "REPLACE" occurs. 3. The following points apply to Format 1 of the "REPLACE" statement: A. Format 1 of the "REPLACE" statement can be used to make changes to program source code in much the same way as the "REPLACING" option of the "COPY" statement can, via these options: Chapter 2 - CDF - Compiler Directing Facility 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 43 <> Replace one or more complete reserved words, user-defined identifiers or literals; the following points apply to this option: • This option cannot be used to replace part of a word, identifier or literal. • Whatever preceeds the "BY" will be referred to here as the search string. • Search strings on "REPLACE" are always specified using the "====" option. For example, to replace all occurrences of "UPON PRINTER", you would specify "==UPON PRINTER==". • The replacement string, which follows the "BY", is specified using the "====" option. If "" is null (in other words, the replacement text is specified as "===="), all encountered occurrences of the search string will be deleted. <> Using this, you may replace character sequences that occur at the be- ginning ("LEADING") or end ("TRAILING") of reserved or user-defined words. For example, to change all words of the form "0100-xxxxxx" to "020-xxxxxx", code "LEADING ==0100-== BY ==020-==". To simply remove all "0100-" prefixes from words, code "LEADING ==0100-== BY ====". B. Once a Format 1 "REPLACE" statement is encountered in the currently-compiling source file, Replace Mode becomes active, and the change(s) specified by that statement will be automatically made on all subsequent source statements the compiler reads from the file. C. Replace Mode remains in-effect — continuing to make source code changes — until another Format 1 "REPLACE" is encountered, the end of currently compiling program source file is reached or a Format 2 "REPLACE" statement is encountered. D. When a Format 1 "REPLACE" statement with the "ALSO" keyword is encountered without Replace Mode being currently active, the effect will be as if the "ALSO" had not been specified. If Replace Mode already was in effect, the effect will be to "push" the current change specification(s) onto the top of a stack and add the specification(s) of the new statement to those that were already in effect. E. When a Format 1 "REPLACE" without the "ALSO" keyword is encountered, any stacked change specification(s), if any, will be discarded and the currently in-effect change specification(s), if any, will be replaced by those of the new statement. F. When the end of the currently-compiling source file is reached, Replace Mode is deactivated and any stacked replace specifications will be discarded — compilation 3 June 2014 Chapter 2 - CDF - Compiler Directing Facility 44 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide of the next source file (if any) will begin with Replace Mode inactive and no change specification(s) on the stack. 4. The following points apply to Format 2 of the "REPLACE" statement: A. If Replace Mode is currently inactive, the Format 2 REPLACE statement will be ignored. B. If Replace Mode is currently active, a "REPLACE OFF." will deactivate Replace Mode and discard any replace specification(s) on the stack. The compiler will henceforth operate as if no "REPLACE" had ever been encountered, until such time as another Format 1 "REPLACE" is encountered. C. If Replace Mode is currently active, a "REPLACE LAST OFF." will replace the cur- rent replace specification(s) with those popped off the top of the stack. If there were no replace specification(s) on the stack, the effect will be as if a "REPLACE OFF." had been coded. Chapter 2 - CDF - Compiler Directing Facility 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 45 2.3. >>DEFINE (cid:11) (cid:10) CDF >>DEFINE Directive Syntax (cid:8) (cid:9) ~~~~~~~~ } >>DEFINE [ CONSTANT ] cdf-variable-1 AS { OFF } { ~~~ ~~~~~~~~ { literal-1 [ OVERRIDE ] } { } { PARAMETER [ OVERRIDE ] } ~~~~~~~~ ~~~~~~~~~ ~~~~~~~~ ———————————————————————————————————————— Use the ">>DEFINE" CDF directive to create CDF variables and (optionally) assign them either literal or environment variable values. 1. The reserved word "AS" is optional and may be included, or not, at the discretion of the programmer. The presence or absence of this word has no effect upon the program. 2. CDF variables defined in this way become undefined once an "END PROGRAM" or "END FUNCTION" directive is encountered in the input source. 3. The ">>DEFINE" CDF directive is one way to create CDF variables that may be pro- cessed by other CDF statements such as ">>IF" (see [>>IF], page 46). The ">>SET" CDF directive (see [>>SET], page 49) provides another way to create them. 4. CDF variable names follow the rules for standard GNU COBOL user-defined names, and may not duplicate any CDF reserved word. CDF variable names may duplicate COBOL reserved words, provided the "CONSTANT" option is not specified, but such names are not recommended. 5. The "CONSTANT" option is valid only in conjunction with . When "CONSTANT" is specified, the CDF variable that is created may be used within your regular COBOL code as if it were a literal value. Without this option, the CDF variable may only be referenced on other CDF statements. The "OFF" option is used to create a variable without assigning it any value. 6. The "PARAMETER" option is used to create a variable whose value is that of the environ- ment variable of the same name. Note that this value assignment occurs at compilation time, not program execution time. 7. In the absence of the "OVERRIDE" option, must not yet have been defined. When the "OVERRIDE" option is specified, will be created with the specified value, if it had not yet been defined. If it had already been defined, it will be redefined with the new value. 3 June 2014 Chapter 2 - CDF - Compiler Directing Facility 46 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 2.4. >>IF (cid:11) (cid:10) CDF >>IF Directive Syntax (cid:8) (cid:9) >>IF CDF-Conditional-Expression-1 ~~~~ [ Program-Source-Lines-1 ] [ >>ELIF CDF-Conditional-Expression-2 ~~~~~~ [ Program-Source-Lines-2 ] ]... [ >>ELSE ~~~~~~ [ Program-Source-Lines-3 ] ] >>END-IF ~~~~~~~~ ———————————————————————————————————————— (cid:11) (cid:8) (cid:10) CDF-Conditional-Expression Syntax (cid:9) } } { cdf-variable-1 } IS [ NOT ] { DEFINED } { ~~~~~~~ { literal-1 } { SET { ~~~ } { CDF-RelOp { cdf-variable-2 } } } } { { literal-2 ~~~ ———————————————————————————————————————— (cid:11) (cid:8) (cid:10) >= > <= < = <> or or or or or or CDF-RelOp Syntax (cid:9) ~~ ~~~~~ GREATER THAN OR EQUAL TO ~~~~~~~ GREATER THAN ~~~~~~~ LESS THAN OR EQUAL TO ~~~~ LESS THAN ~~~~ EQUAL TO ~~~~~ EQUAL TO (with "NOT") ~~~~~ ~~ ~~~~~ ———————————————————————————————————————— Chapter 2 - CDF - Compiler Directing Facility 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 47 The ">>IF" CDF directive causes the GNU COBOL compiler to process or ignore COBOL source statements, CDF text-manipulation statements and/or CDF directives depending upon the value of one or more conditional expressions based upon CDF variables. 1. The reserved words "IS", "THAN" and "TO" are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program. 2. Each ">>IF" directive must be terminated by an ">>END-IF" directive. 3. There may be any number of ">>ELIF" clauses following an ">>IF", including zero. 4. There may no more than one ">>ELSE" clause following an ">>IF". When ">>ELSE" is used, it must follow the ">>IF" and all ">>ELIF" clauses. 5. Only one of the <> block of statements that lie within the scope of the ">>IF"-">>END-IF" may be processed by the compiler. Which one (if any) that gets processed will be decided as follows: A. Each <> will be evaluated, in turn, in the se- quence in which they are coded in the >>IF statement and any ">>ELIF" clauses that may be present until one evaluates to TRUE. Once one of them evaluates to TRUE, the <> block of code that corresponds to the TRUE <> will be one that is processed. All oth- ers within the ">>IF"-">>END-IF" scope will be ignored. B. If no <> evaluates to TRUE, and there is an ">>ELSE" clause, the <> block of statements following the ">>ELSE" clause will be processed by the compiler and all others within the ">>IF"-">>END-IF" scope will be ignored. C. If no <> evaluates to TRUE and there is no ">>ELSE" clause, then none of the <> block of statements within the ">>IF"-">>END-IF" scope will be processed by the compiler. D. If the > statement block selected for processing is empty, no error results — there will just be no code generated from the ">>IF"-">>END-IF" structure. 6. A <> block may contain any valid COBOL or CDF code. 7. The following points pertain to any <>: A. The "DEFINED" option tests for whether has been defined, but not yet assigned a value (">>DEFINE ... OFF"); use the "NOT" option to test for the variable not being defined. B. The "SET" option tests for whether has been given a value, either via a ">>SET" statement or via a ">>DEFINE" without the "OFF" option. C. Two CDF variables, two literals or a single CDF variable and a single literal may 3 June 2014 Chapter 2 - CDF - Compiler Directing Facility 48 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide be compared against each other using a relational operator. Unlike the standard GNU COBOL "IF" statement (see [IF], page 397), multiple comparisons cannot be "AND"ed or "OR"ed together; you may nest a second ">>IF" inside the first, however, to simulate an "AND" and an "OR" may be simulated via the ">>ELIF" option. D. The "<>" symbol stands for "NOT EQUAL TO". Chapter 2 - CDF - Compiler Directing Facility 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 49 2.5. >>SET (cid:11) (cid:10) CDF >>SET Directive Syntax (cid:8) (cid:9) ~~~~~~~~ >>SET { [ CONSTANT ] cdf-variable-1 [ AS literal-1 ] } } ~~~~~ { } } } } } { SOURCEFORMAT AS FIXED|FREE { ~~~~~~~~~~~~ ~~~~~ ~~~~ { NOFOLDCOPYNAME { ~~~~~~~~~~~~~~ { FOLDCOPYNAME AS UPPER|LOWER ~~~~~ ~~~~~ ~~~~~~~~~~~~ ~~ ———————————————————————————————————————— The ">>SET" CDF directive provides an alternate means of performing the actions of the ">>DEFINE" and ">>SOURCE" directives, as well as a means of controlling the compiler’s "-free" switch, "-fixed" switch and "-ffold-copy" switch from within program source code. 1. The reserved word "AS" is optional (only on the "SOURCEFORMAT" and "FOLDCOPYNAME" clauses) and may be included, or not, at the discretion of the programmer. The presence or absence of this word has no effect upon the program. 2. CDF variables defined in this way become undefined once an "END PROGRAM" or "END FUNCTION" directive is encountered in the input source. 3. The "FOLDCOPYNAME" option provides the equivalent of specifying the compiler "-ffold-copy=xxx" switch, where "xxx" is either "UPPER" or "LOWER". 4. The "NOFOLDCOPYNAME" option turns off the effect of either the ">>SET FOLDCOPYNAME" statement or the compiler "-ffold-copy=xxx" switch. 5. If the "CONSTANT" option is used, must also be used. This option provides another means of defining constants that may be used anywhere in the program that a literal could be specified. 6. The remaining options of the ">>SET" CDF directive provide equivalent functionality to the ">>DEFINE" and ">>SOURCE" directives, as follows: A. ">>SET " ≡ ">>DEFINE AS OFF" B. ">>SET AS " ≡ ">>DEFINE AS " C. ">>SET CONSTANT AS " ≡ ">>DEFINE CONSTANT AS " D. ">>SET SOURCEFORMAT AS FIXED" ≡ ">>SOURCE FORMAT IS FIXED" E. ">>SET SOURCEFORMAT AS FREE" ≡ ">>SOURCE FORMAT IS FREE" 3 June 2014 Chapter 2 - CDF - Compiler Directing Facility 50 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 2.6. >>SOURCE (cid:11) (cid:10) CDF >>SOURCE Directive Syntax >>SOURCE FORMAT IS FIXED|FREE ~~~~~ ~~~~ ~~~~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— The ">>SOURCE" CDF directive puts the compiler into "FIXED" or "FREE" source-code format mode. This, in effect, provides yet another mechanism for controlling the compiler’s "-free" switch and "-fixed" switch. 1. The reserved words "FORMAT" and "IS" are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program. 2. You may switch between "FIXED" and "FREE" mode as desired. 3. You may also use the ">>SET" CDF directive to perform this function. 4. If the compiler is already in the specified mode, this statement will have no effect. Chapter 2 - CDF - Compiler Directing Facility 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 51 2.7. >>TURN (cid:11) (cid:10) CDF >>TURN Directive Syntax >>TURN { exception-name-1 [ file-name-1 ]... ~~~~~~ }... } { OFF { ~~~ } { CHECKING ON [ WITH LOCATION ] } ~~~~~~~~ ~~ ~~~~~~~~ (cid:8) (cid:9) The ">>TURN" CDF directive is syntactically recognized but is otherwise non-functional. ———————————————————————————————————————— ———————————————————— End of Chapter 2 — CDF - Compiler Directing Facility 3 June 2014 Chapter 2 - CDF - Compiler Directing Facility GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 53 3. IDENTIFICATION DIVISION (cid:11) (cid:10) IDENTIFICATION DIVISION Syntax [ IDENTIFICATION DIVISION. ] ~~~~~~~~~~~~~~ ~~~~~~~~ { PROGRAM-ID. } program-id [ AS literal-1 ] [ Type-Clause ] . { ~~~~~~~~~~ } { FUNCTION-ID. } ~~~~~~~~~~~ (cid:8) (cid:9) [ AUTHOR. comment-1. ] ~~~~~~ [ DATE-COMPILED. comment-2. ] ~~~~~~~~~~~~~ [ DATE-WRITTEN. comment-3. ] ~~~~~~~~~~~~ [ INSTALLATION. comment-4. ] ~~~~~~~~~~~~ [ REMARKS. comment-5. ] ~~~~~~~ [ SECURITY. comment-6. ] ~~~~~~~~ The "AUTHOR", "DATE-COMPILED", "DATE-WRITTEN", "INSTALLATION", "REMARKS" and "SECURITY" paragraphs are supported by GNU COBOL only to provide compatibility with programs written for the ANS1974 (or earlier) standards. As of the ANS1985 standard, these clauses have become obsolete and should not be used in new programs. ———————————————————————————————————————— (cid:11) (cid:8) (cid:10) PROGRAM-ID Type Clause Syntax (cid:9) IS [ COMMON ] [ INITIAL|RECURSIVE PROGRAM ] ~~~~~~ ~~~~~~~ ~~~~~~~~~ ———————————————————————————————————————— The identification division provides basic identification of the program by giving it a name and optionally defining some high-level characteristics via the eight pre-defined paragraphs that may be specified. 1. The paragraphs shown above may be coded in any sequence. 2. The reserved words "AS", "IS" and "PROGRAM" are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program. 3 June 2014 Chapter 3 - IDENTIFICATION DIVISION 54 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 3. A Type Clause may be coded only when "PROGRAM-ID" is specified. If one is coded, either "COMMON", "COMMON INITIAL" or "COMMON RECURSIVE" must be specified. 4. While the actual "IDENTIFICATION DIVISION" header is optional, the "PROGRAM-ID" / "FUNCTION-ID" paragraphs are not; only one or the other, however, may be coded. 5. The compiler’s "-Wobsolete" switch will cause the GNU COBOL compiler to issue warnings messages if these (or any other obsolete syntax) is used in a program. 6. If specified, must be an actual alphanumeric literal and may not be a figu- rative constant. 7. The "PROGRAM-ID" and "FUNCTION-ID" paragraphs serve to identify the program to the external (i.e. operating system) environment. If there is no "AS" clause present, the will serve as that external identification. If there is an "AS" clause specified, that specified literal will serve as the external identification. For the remain- der of this document, that "external identification" will be referred to as the primary entry-point name. 8. The "INITIAL", "COMMON" and "RECURSIVE" words are used only within subprograms serving as subroutines. Their purposes are as follows: A. "COMMON" should be used only within subprograms that are nested subprograms. A nested subprogram declared as "COMMON" may be called from any nested program in the source file being compiled, not just those "above" it in the nesting structure. B. The "RECURSIVE" clause, if any, will cause the compiler to generate different object code for the subprogram that will enable it to invoke itself and to properly return back to the program that invoked it. User-defined functions (i.e. "FUNCTION-ID") are always recursive. C. The "INITIAL" clause, if specified, guarantees the subprogram will be in its initial (i.e. compiled) state each and every time it is executed, not just the first time. ———————————————————— End of Chapter 3 — IDENTIFICATION DIVISION Chapter 3 - IDENTIFICATION DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 55 4. ENVIRONMENT DIVISION (cid:11) (cid:10) ENVIRONMENT DIVISION Syntax (cid:8) (cid:9) ENVIRONMENT DIVISION. ~~~~~~~~~~~ ~~~~~~~~ [ CONFIGURATION SECTION. ] ~~~~~~~~~~~~~ ~~~~~~~~ [ SOURCE-COMPUTER. ~~~~~~~~~~~~~~~ [ OBJECT-COMPUTER. ~~~~~~~~~~~~~~~ [ REPOSITORY. ~~~~~~~~~~ [ SPECIAL-NAMES. ~~~~~~~~~~~~~ [ INPUT-OUTPUT SECTION. ] ~~~~~~~~~~~~ ~~~~~~~ [ FILE-CONTROL. ~~~~~~~~~~~~ [ I-O-CONTROL. ~~~~~~~~~~~ Compilation-Computer-Specification . ] Execution-Computer-Specification . ] Function-Specification... . ] Program-Configuration-Specification . ] General-File-Description... . ] File-Buffering Specification... . ] ———————————————————————————————————————— This division defines the external computer environment in which the program will be operating. This includes defining any files that the program may be . • If both optional sections of this division are coded, they must be coded in the sequence shown. • The paragraphs within the sections may be coded in any order. • These consist sections paragraphs ("SOURCE-COMPUTER" and "OBJECT-COMPUTER", each of which serves a specific purpose. If no code is required for the purpose one of the paragraphs serves, the entire paragraph may be omitted. specific, for pre-defined, example), series of of a • If any of the paragraphs within one of the sections are coded, the section header itself must be coded. • If none of the paragraphs within one of the sections are coded, the section header itself may be omitted. • If none of the sections within the environment division are coded, the "ENVIRONMENT DIVISION." header itself may be omitted. 3 June 2014 Chapter 4 - ENVIRONMENT DIVISION 56 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 4.1. CONFIGURATION SECTION (cid:11) (cid:10) CONFIGURATION SECTION Syntax CONFIGURATION SECTION. ~~~~~~~~~~~~~ ~~~~~~~ [ SOURCE-COMPUTER. Compilation-Computer-Specification . ] ~~~~~~~~~~~~~~~ [ OBJECT-COMPUTER. Execution-Computer-Specification . ] ~~~~~~~~~~~~~~~ [ REPOSITORY. ~~~~~~~~~~ [ SPECIAL-NAMES. ~~~~~~~~~~~~~ Function-Specification... . ] Program-Configuration-Specification . ] (cid:8) (cid:9) ———————————————————————————————————————— This section defines the computer system upon which the program is being compiled and executed and also specifies any special environmental configuration or compatibility char- acteristics. 1. The four paragraphs in this section may be specified in any order. 2. The configuration section is not allowed in a nested subprogram — nested programs will inherit the configuration section settings of their parent program. 3. If none of the features provided by the configuration section are required by a program, the entire "CONFIGURATION SECTION." header may be omitted from the program. Chapter 4 - ENVIRONMENT DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 57 4.1.1. SOURCE-COMPUTER (cid:11) (cid:10) SOURCE-COMPUTER Syntax SOURCE-COMPUTER. computer-name [ WITH DEBUGGING MODE ] . ~~~~~~~~~~~~~~~ ~~~~~~~~~ ~~~~ (cid:8) (cid:9) ———————————————————————————————————————— This paragraph defines the computer upon which the program is being compiled and pro- vides one way in which debugging code imbedded within the program may be activated. 1. The reserved word "WITH" is optional and may be included, or not, at the discretion of the programmer. The presence or absence of this word has no effect upon the program. 2. This paragraph is not allowed in a nested subprogram — nested programs will inherit the "SOURCE-COMPUTER" settings of their parent program. 3. The value specified for is irrelevant, provided it is a valid COBOL word that does not match any GNU COBOL reserved word. The value may include spaces. This need not match the used with the "OBJECT-COMPUTER" paragraph, if any. 4. The "DEBUGGING MODE" clause, if present, will inform the compiler that debugging lines (those with a "D" in column 7 if Fixed Source Mode is in effect, or those prefixed with a ">>D" if Free Source Mode is in effect) — normally treated as comments — are to be compiled. 5. Even without the "DEBUGGING MODE" clause, it is still possible to compile debugging lines. Debugging lines may also be compiled by specifying the "-fdebugging-line" switch to the GNU COBOL compiler. 3 June 2014 Chapter 4 - ENVIRONMENT DIVISION 58 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 4.1.2. OBJECT-COMPUTER (cid:11) (cid:10) OBJECT-COMPUTER Syntax OBJECT-COMPUTER. [ computer-name ] ~~~~~~~~~~~~~~~ [ MEMORY SIZE IS integer-1 WORDS|CHARACTERS ] ~~~~~~ ~~~~ ~~~~~ ~~~~~~~~~~ [ PROGRAM COLLATING SEQUENCE IS alphabet-name-1 ] ~~~~~~~~~ [ SEGMENT-LIMIT IS integer-2 ] ~~~~~~~~~~~~~ (cid:8) (cid:9) [ CHARACTER CLASSIFICATION IS { locale-name-1 ~~~~~~~~~~~~~~ } ] } { LOCALE } { ~~~~~~ } { USER-DEFAULT } { ~~~~~~~~~~~~ { SYSTEM-DEFAULT } ~~~~~~~~~~~~~~ . The "MEMORY SIZE" and "SEGMENT-LIMIT" clauses are syntactically recognized but are otherwise non-functional. ———————————————————————————————————————— This paragraph describes the computer upon which the program will execute. 1. The , if specified, must immediately follow the "OBJECT-COMPUTER" paragraph name. The remaining clauses may be coded in any sequence. 2. The reserved words "CHARACTER", "IS", "PROGRAM" and "SEQUENCE" are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program. 3. The value specified for , if any, is irrelevant provided it is a valid COBOL word that does not match any GNU COBOL reserved word. The may include spaces. This need not match the used with the "SOURCE-COMPUTER" paragraph, if any. 4. The "OBJECT-COMPUTER" paragraph is not allowed in a nested subprogram — nested programs will inherit the "OBJECT-COMPUTER" settings of their parent program. 5. The "COLLATING SEQUENCE" clause allows you to specify a customized character collat- ing sequence to be used when alphanumeric values are compared to one another. Data will still be stored in the characterset native to the computer, but the logical sequence in which characters are ordered for comparison purposes can be altered from that de- Chapter 4 - ENVIRONMENT DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 59 fined by the computer’s native characterset. The you specify needs to be defined in the "SPECIAL-NAMES" (see [SPECIAL-NAMES], page 62) paragraph. 6. If no "COLLATING SEQUENCE" clause is specified, the collating sequence implied by the characterset native to the computer (usually ASCII) will be used. 7. The optional "CLASSIFICATION" clause may be used to specify a locale for the envi- ronment in which the program will be executing, for the purpose of influencing the uppercase and lowercase mappings of characters for the "UPPER-CASE" (see [UPPER- CASE], page 334) and "LOWER-CASE" (see [LOWER-CASE], page 285) intrinsic func- tions and the classification of characters for the "ALPHABETIC", "ALPHABETIC-LOWER" and "ALPHABETIC-UPPER" class tests. The definitions of these classes will be taken from the cultural convention specification ("LC_CTYPE") from the specified locale. The meanings of the four locale specifications are as follows: A. references a "LOCALE" (see [SPECIAL-NAMES], page 62) defini- tion. B. The keyword "LOCALE" refers to the current locale (in effect at the time the pro- gram is executed) C. The keyword "USER-DEFAULT" references the default locale specified for the user currently executing this program. D. The keyword "SYSTEM-DEFAULT" denotes the default locale specified for the com- puter upon which the program is executing. 8. Absence of a "CLASSIFICATION" clause will cause character classification to occur ac- cording to the rules for the computer’s native characterset (ASCII, EBCDIC, . . . ). 3 June 2014 Chapter 4 - ENVIRONMENT DIVISION 60 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 4.1.3. REPOSITORY (cid:11) (cid:10) REPOSITORY. ~~~~~~~~~~ REPOSITORY Syntax (cid:8) (cid:9) FUNCTION { function-prototype-name-1 [ AS literal-1 ] }... ~~~~~~~~ { ~~ } { intrinsic-function-name-1 [ AS literal-2 ] } } { } { intrinsic-function-name-2 INTRINSIC { ALL INTRINSIC } ~~~~~~~~~ ~~~ ~~~~~~~~~ ~~ ———————————————————————————————————————— The REPOSITORY paragraph provides a way to control access to the various built-in intrinsic functions and any user defined functions that your program will be using. 1. The "REPOSITORY" paragraph is not allowed in a nested subprogram — nested pro- grams will inherit the "REPOSITORY" settings of their parent program. 2. The "INTRINSIC" clause allows you to flag one or more (or "ALL") built-in intrinsic functions as being usable without the need to code the keyword "FUNCTION" in front of the function names. 3. As an alternative to using the "ALL INTRINSIC" clause, you may instead compile your GNU COBOL programs using the "-fintrinsics=ALL" switch. 4. The option is required to specify the name of a user- defined function your program will be using. Optionally, should you desire, you may specify an alias name by which you will reference that user-defined function. Should you wish, you may also use the "AS" clause to provide an alias name for a built-in intrinsic function. 5. The following example enables all the "FUNCTION" keyword, intrinsic functions to be specified without the use of two user-defined functions named "MY-FUNCTION-1" and "MY-FUNCTION-2" that will be used by the program and (3) specifies the alias names "SIGMA" for the intrinsic function "STANDARD-DEVIATION" and "MF2" for "MY-FUNCTION-2". (2) names REPOSITORY. FUNCTION ALL INTRINSIC. FUNCTION MY-FUNCTION-1. FUNCTION MY-FUNCTION-2 AS "MF2". FUNCTION STANDARD-DEVIATION AS "SIGMA". A special note about user-defined functions — because you must name a user-defined func- Chapter 4 - ENVIRONMENT DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 61 tion that your program will be using in the "REPOSITORY" paragraph, you may always reference that function from your program’s procedure division without needing to use the "FUNCTION" keyword. 3 June 2014 Chapter 4 - ENVIRONMENT DIVISION 62 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 4.1.4. SPECIAL-NAMES (cid:11) (cid:10) SPECIAL-NAMES. ~~~~~~~~~~~~~ SPECIAL-NAMES Syntax [ CALL-CONVENTION integer-1 IS mnemonic-name-1 ] (cid:8) (cid:9) ~~~~~~~~~~~~~~~ [ CONSOLE IS CRT ] ~~~~~~~ ~~~ [ CRT STATUS IS identifier-1 ] ~~~ ~~~~~~ [ CURRENCY SIGN IS literal-1 ] ~~~~~~~~ ~~~~ [ CURSOR IS identifier-2 ] ~~~~~~ [ DECIMAL-POINT IS COMMA ] ~~~~~~~~~~~~~ ~~~~~ [ EVENT STATUS IS identifier-3 ] ~~~~~ ~~~~~~ [ LOCALE locale-name-1 IS literal-2 ]... ~~~~~~ [ NUMERIC SIGN IS TRAILING SEPARATE ] ~~~~~~~ ~~~~ ~~~~~~~~ ~~~~~~~~ [ SCREEN CONTROL IS identifier-4 ] ~~~~~~ ~~~~~~~ [ device-name-1 IS mnemonic-name-2 ]... [ feature-name-1 IS mnemonic-name-3 ]... [ Alphabet-Clause ]... [ Class-Definition-Clause ]... [ Switch-Definition-Clause ]... [ Symbolic-Characters-Clause ]... . The "EVENT STATUS" and "SCREEN CONTROL" clauses are syntactically recognized but are otherwise non-functional. ———————————————————————————————————————— <>, <>, <> and <> are discussed in detail in the next four sections. Chapter 4 - ENVIRONMENT DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 63 The "SPECIAL-NAMES" paragraph provides a means for specifying various program and operating environment configuration options. 1. The various clauses that may be specified within the "SPECIAL-NAMES" paragraph may be coded in any order. 2. The reserved word "IS" is optional and may be included, or not, at the discretion of the programmer. The presence or absence of this word has no effect upon the program. 3. The "SPECIAL-NAMES" paragraph is not allowed in a nested subprogram — nested programs will inherit the "SPECIAL-NAMES" settings of their parent program. 4. Only the final clause specified within this paragraph should be terminated with a period. 5. The "CALL-CONVENTION" clause allows a decimal integer, representing a series of ON/OFF switch settings, to be associated with a mnemonic name which may then be coded on a "CALL" statement (see [CALL], page 359). The switch settings defined by this mnemonic will then control how the linkage to a subroutine invoked by the "CALL" statement that references will be handled. 6. The "CONSOLE IS CRT" clause, if specified, will cause a "DISPLAY" statement lack- ing an explict "UPON" clause to be treated as a "DISPLAY screen-data-item" state- ment (see [DISPLAY screen-data-item], page 374), and any "ACCEPT" statement lack- ing a "FROM" clause to be treated as a "ACCEPT screen-data-item" statement (see [ACCEPT screen-data-item], page 342). 7. If the "CRT STATUS" clause is not specified, an implicit "COB-CRT-STATUS" identifier (with a "PICTURE 9(4)") will be allocated for the purpose of receiving screen "ACCEPT" statuses. If "CRT STATUS" is specified, then must be defined in the program as a "PICTURE 9(4)" field. 8. The "CURRENCY SIGN" clause may be used to redefine the character to be used as a currency sign in a "PICTURE" (see [PICTURE], page 162) clause. The default currency sign is a dollar-sign ($). You may specify any character except "0"-"9", "A"-"Z", "a"-"z", "+", "-", ",", ".", "*", "/", ";", "(", ")", "=", "\", quote (") or space. 9. The "CURSOR IS" clause allows you to specify a 4- or 6-character data item into which the cursor screen location at the time a screen "ACCEPT" is satisfied. The value will be returned as rrcc or rrrccc, depending upon the length of the specified , where rr and rrr represent the row number (starting at zero) and cc and ccc represent the column number (also starting at zero). There is no default data item allocated for this data if the "CURSOR IS" clause is not specified, and it is the programmer’s responsibility to define if the clause is specified. 10. The "DECIMAL POINT IS COMMA" clause reverses the definition of the "," and "." char- acters when they are used as "PICTURE" editing symbols and within numeric literals. This can have unwanted side-effects - see [Punctuation], page 36. 11. The "LOCALE" clause may be used to associate external OS-defined locale names () with an internal name () that may then be referenced 3 June 2014 Chapter 4 - ENVIRONMENT DIVISION 64 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide within the program. Locale names are defined by the Operating System and/or C compiler GNU COBOL will be utilizing on your computer. 12. The following is the list of possible locale codes, for example, that would be available on a Windows computer running a GNU COBOL version that was built utilizing the MinGW Unix-emulator and the GNU C compiler (gcc): A B C D E F G H I J K L M N O P Q R af ZA, am ET, ar AE, ar BH, ar DZ, ar EG, ar IQ, ar JO, ar KW, ar LB, ar LY, ar MA, ar OM, ar QA, ar SA, ar SY, ar TN, ar YE, arn CL, as IN, az Cyrl AZ, az Latn AZ ba R, be BY, bg BG, bn IN bo BT, bo CN, br FR, bs Cyrl BA, bs Latn BA ca ES, cs CZ, cy GB da DK, de AT, de CH, de DE, de LI, de LU, dsb DE, dv MV el GR, en 029, en AU, en BZ, en CA, en GB, en IE, en IN, en JM, en MY en NZ, en PH, en SG, en TT, en US, en ZA, en ZW, es AR, es BO, es CL, es CO, es CR, es DO, es EC, es ES, es GT, es HN, es MX, es NI, es PA, es PE, es PR, es PY, es SV, es US, es UY es VE, et EE, eu ES fa IR, fi FI, fil PH, fo FO, fr BE, fr CA, fr CH, fr FR, fr LU, fr MC, fy NL ga IE, gbz AF, gl ES, gsw FR, gu IN ha Latn NG, he IL, hi IN, hr BA, hr HR, hu HU, hy AM id ID, ig NG, ii CN, is IS, it CH, it IT, iu Cans CA, iu Latn CA ja JP ka GE, kh KH, kk KZ, kl GL, kn IN, ko KR, kok IN, ky KG lb LU, lo LA, lt LT, lv LV mi NZ, mk MK, ml IN, mn Cyrl MN, mn Mong CN moh CA, mr IN, ms BN, ms MY, mt MT nb NO, ne NP, nl BE, nl NL, nn NO, ns ZA oc FR, or IN pa IN, pl PL, ps AF, pt BR, pt PT qut GT, quz BO, quz EC, quz PE rm CH, ro RO, ru RU, rw RW Chapter 4 - ENVIRONMENT DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 65 S T U V W X Y Z sa IN, sah RU, se FI, se NO se SE, si LK, sk SK, sl SI, sma NO, sma SE, sr Cyrl BA, smn FI, sr Cyrl CS, sr Latn BA, sr Latn CS, sv FI, sv SE, sw KE syr SY smj NO, smj SE, sms FI, sq AL, ta IN, te IN, tg Cyrl TJ, th TH tk TM, tmz Latn DZ, tn ZA, tr IN, tr TR, tt RU ug CN, uk UA, ur PK, uz Cyrl UZ, uz Latn UZ vi VN wen DE, wo SN xh ZA yo NG zh CN, zh HK, zh MO, zh SG, zh TW, zu ZA 13. The "NUMERIC SIGN TRAILING SEPARATE" specification causes all signed numeric "USAGE DISPLAY" data items to be created as if the "SIGN IS TRAILING SEPARATE CHARACTER" clause was included in their definitions. 14. The " IS " clause allows you to specify an al- ternate name () for one of the built-in GNU COBOL device name . The list of device names built-into GNU COBOL, and the phys- ical device associated with that name, are as follows: This is the (screen-mode) display of the PC or Unix system. These devices (they are all synonymous) represent standard system input (pipe 0). On a PC or UNIX system, this is typically the keyboard. The contents of a file may be delivered to a GNU COBOL program for access via one of these device names by adding the sequence "0< filename" to the end of the programs execution command. "CONSOLE" "STDIN" "SYSIN" "SYSIPT" "PRINTER" "STDOUT" "SYSLIST" "SYSLST" "SYSOUT" These devices (they are all synonymous) represent standard system output (pipe 1). On a PC or UNIX system, this is typically the display. Output 3 June 2014 Chapter 4 - ENVIRONMENT DIVISION 66 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide sent to one of these devices by a GNU COBOL program can be sent to a file by adding the sequence "1> filename" to the end of the programs execution command. "STDERR" "SYSERR" These devices (they are synonymous) represent standard system error out- put (pipe 2). On a PC or UNIX system, this is typically the display. Output sent to one of these devices by a GNU COBOL program can be sent to a file by adding the sequence "2> filename" to the end of the programs execution command. 15. The " IS " clause allow for mnemonic names to be assigned to up to the 13 printer channel (i.e. vertical page positioning) position feature names "Cnn" (nn=01-12) and "CSP". Once a channel position has been assigned a mnemonic name, statements of the form "WRITE AFTER ADVANCING " may be coded to write the specified print record at the channel position assigned to . Printers supporting channel positioning are generally mainframe-type line printers. When writing to printers that do not support channel positioning, a formfeed will be issued to the printer. The "CSP" positioning option stands for "No Spacing". Testing on a MinGW build of GNU COBOL shows that this too results in a formfeed being issued. Chapter 4 - ENVIRONMENT DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 67 4.1.4.1. Alphabet-Name-Clause (cid:11) (cid:10) SPECIAL-NAMES Alphabet-Clause Syntax } ALPHABET alphabet-name-1 IS { ASCII } { ~~~~~ ~~~~~~~~ } { EBCDIC } { ~~~~~~ } { NATIVE } { ~~~~~~ } { STANDARD-1 } { ~~~~~~~~~~ } { STANDARD-2 { ~~~~~~~~~~ } { Literal-Clause... } (cid:8) (cid:9) ———————————————————————————————————————— (cid:11) (cid:8) (cid:10) SPECIAL-NAMES ALPHABET Literal-Clause Syntax (cid:9) literal-1 [ { THRU|THROUGH literal-2 } ] { ~~~~ ~~~~~~~ { {ALSO literal-3}... } } ~~~~ ———————————————————————————————————————— The "ALPHABET" clause provides a means for relating a name to a specified character code set or collating sequence, including those you define yourself using the option. 1. The reserved word "IS" is optional and may be included, or not, at the discretion of the programmer. The presence or absence of this word has no effect upon the program. 2. The reserved words "THRU" and "THROUGH" are interchangeable. 3. GNU COBOL considers "ASCII", "STANDARD-1" and "STANDARD-2" to be interchange- able. 4. "NATIVE" specifies the system default characterset. 5. The following points apply to using the specifications to compose a custom characterset: A. The values are either integers or alphanumeric quoted characters. These represent a single character in the "NATIVE" characterset, either by it’s actual text value (alphanumeric quoted character) or by ordinal position in the "NATIVE" characterset (integer), 3 June 2014 Chapter 4 - ENVIRONMENT DIVISION 68 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide B. The sequence in which characters are defined in this clause specifies the relative order those characters should have when comparisons are made using this alphabet. C. Character positions in this list do not affect the actual binary storage values used for the characters — binary values will still be those of the "NATIVE" characterset. D. You may specify any of the figurative constants "SPACE", "SPACES", "ZERO", "ZEROS", "ZEROES", "QUOTE", "QUOTES", "HIGH-VALUE", "HIGH-VALUES", "LOW-VALUE" or "LOW-VALUES" for any of the , or specifications. 6. Once you have defined an alphabet name, that alphabet name may be used on speci- fications in "CODE-SET", "COLLATING SEQUENCE", or "SYMBOLIC CHARACTERS" clauses elsewhere in the program. Chapter 4 - ENVIRONMENT DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 69 4.1.4.2. Class-Definition-Clause (cid:11) (cid:10) SPECIAL-NAMES Class-Definition-Clause Syntax CLASS class-name-1 IS { literal-1 [ THRU|THROUGH literal-2 ] }... ~~~~~ ~~~~ ~~~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— 1. The reserved word "IS" is optional and may be included, or not, at the discretion of the programmer. The presence or absence of this word has no effect upon the program. 2. The reserved words "THRU" and "THROUGH" are interchangeable. 3. Both and must be alphanumeric literals of length 1. 4. The literal(s) specified on this clause define the possible characters that may be found in a data item’s value in order to be considered part of the class. 5. For example, the following defines a class called "Hexadecimal", the definition of which specifies the only characters that may be present in an alphanumeric data item if that data item is to be part of the "Hexadecimal" class: CLASS Hexadecimal IS ’0’ THRU ’9’ ’A’ THRU ’F’ ’a’ THRU ’f’ 6. Once class "Hexadecimal" has been defined, program code could then use a statement such as "IF input-item IS Hexadecimal" to determine if the value of characters in a data item are valid according to that class. 3 June 2014 Chapter 4 - ENVIRONMENT DIVISION 70 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 4.1.4.3. Switch-Definition-Clause (cid:11) (cid:10) SPECIAL-NAMES Switch-Definition-Clause Syntax (cid:8) (cid:9) switch-name-1 [ IS mnemonic-name-1 ] [ ON STATUS IS condition-name-1 ] ~~ [ OFF STATUS IS condition-name-2 ] ~~~ ———————————————————————————————————————— The switch-definition clause associates a condition-name with a run-time execution switch so that the status of that switch may be tested from within a program. 1. The reserved words "IS" and "STATUS" are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program. 2. The valid names are "SWITCH-n" (n=0-15). 3. If the program is compiled with the "-fsyntax-extension" switch, the switch names "SWn" (n=0-15) are also valid; they correspond to "SWITCH-0" through "SWITCH-15", respectively. 4. At execution time, each switch will be associated with a "COB_SWITCH_n" run-time environment variable (see [Run Time Environment Variables], page 522), where "n" will have the value "0" through "15". Any of these sixteen environment variables that have the value "ON" (regardless of upper- or lower-case value) will be considered to be set "on". Any of these sixteen environment variables having no value at all or a value other than "ON" will be considered "OFF". 5. Each specified switch must have at least one of a "IS ", "ON STATUS" or an "OFF STATUS" option defined for it, otherwise there will be no way to reference the switch from within a GNU COBOL program. 6. The "IS " syntax provides a means for setting the switch to either an ON or OFF value via the "SET" statement (see [SET], page 445). 7. The "ON STATUS" and "OFF STATUS" syntax provides a way of associating a condition- name with either the on or off status of the switch, so that status may be tested at execution time via the "IF" statement (see [IF], page 397). Chapter 4 - ENVIRONMENT DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 71 4.1.4.4. Symbolic-Characters-Clause (cid:11) (cid:10) SPECIAL-NAMES-Symbolic-Characters-Clause Syntax SYMBOLIC CHARACTERS ~~~~~~~~ { symbolic-character-1... IS|ARE integer-1... }... [ IN alphabet-name-1 ] ~~ (cid:8) (cid:9) ———————————————————————————————————————— This clause may be used to define your own figurative constants. 1. The reserved words "ARE", "CHARACTERS" and "IS" are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program. 2. There must be exactly as many values specified as there are names. 3. Each symbolic character name will be associated with the corresponding th character in the alphabet named in the "IN" clause. The integer values are selecting characters from the alphabet by their ordinal position and not by their numeric value; thus, an integer of 15 will select the 15th character in the specified alphabet, regardless of the actual numeric value of the bit pattern that constitutes that character. 4. If no is specified, the systems native characterset will be assumed. 5. The following two code examples define the same set of figurative constant names for five ASCII control characters (assuming that ASCII is the system’s native characterset). The two examples are identical in their effects, even though the manner in which the figurative constants are defined is different. SYMBOLIC CHARACTERS NUL IS 1 SOH IS 2 BEL IS 8 DC1 IS 18 DC2 IS 19 SYMBOLIC CHARACTERS NUL SOH BEL DC1 DC2 19 ARE 18 8 2 1 3 June 2014 Chapter 4 - ENVIRONMENT DIVISION 72 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 4.2. INPUT-OUTPUT SECTION (cid:11) (cid:10) INPUT-OUTPUT SECTION Syntax (cid:8) (cid:9) [ INPUT-OUTPUT SECTION. ] ~~~~~~~~~~~~ ~~~~~~~ [ FILE-CONTROL. ] ~~~~~~~~~~~~ [ SELECT-Statement... ] [ I-O-CONTROL. ] ~~~~~~~~~~~ [ MULTIPLE-FILE-Statement ] [ SAME-RECORD-Statement ] ———————————————————————————————————————— The "INPUT-OUTPUT" section provides for the definition of any files the program will be accessing as well as control of the I/O buffering process against those files through the "FILE-CONTROL" and "I-O-CONTROL" paragraphs, respectively. 1. As the diagram shows, there are three types of statements that may occur in the If none of the statements are coded in a particular two paragraphs of this section. paragraph, the paragraph itself may be omitted, otherwise it is required. 2. If neither paragraph is coded, the "INPUT-OUTPUT SECTION." header itself may be omitted, otherwise it is normally required. 3. If the compiler "config" file you are using has "relaxed-syntax-check" set to "yes", the "FILE-CONTROL" and "I-O-CONTROL" paragraphs may be specified without the "INPUT-OUTPUT SECTION." header having been coded. 4. If both statement types are coded in the "I-O-CONTROL" paragraph, the order in which those statements are coded is irrelevant. Chapter 4 - ENVIRONMENT DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 73 4.2.1. SELECT (cid:11) (cid:10) SELECT Statement Syntax (cid:8) (cid:9) ~~~ { word-1 { literal-1 SELECT [ [ NOT ] OPTIONAL ] file-name-1 ~~~~~~ [ ASSIGN { TO ~~~~~~ { USING } { ~~~~~~~~ } { DYNAMIC } ~~~~~~~ ~~~~~~~~ }] [{ identifier-1 }] ] } [{ EXTERNAL }] [{ DISC|DISK } { ~~~~ ~~~~ } { DISPLAY } { ~~~~~~~ } { KEYBOARD { ~~~~~~~~ } { LINE ADVANCING } { ~~~~ ~~~~~~~~~ } } { PRINTER } { ~~~~~~~ } { RANDOM } { ~~~~~~ { TAPE } ~~~~ [ COLLATING SEQUENCE IS alphabet-name-1 ] } } ~~~~~~~~~ [ FILE|SORT ] STATUS IS identifier-2 [ identifier-3 ] ] ~~~~ ~~~~ ~~~~~~ } ] [ LOCK MODE IS { MANUAL|AUTOMATIC { ~~~~~~ ~~~~~~~~~ } { EXCLUSIVE [ WITH { LOCK ON MULTIPLE RECORDS } ] } ~~~~ ~~~~~~~~~ [ ORGANIZATION-Clause ] { ~~~~ ~~ ~~~~~~~~ ~~~~~~~ } } { LOCK ON RECORD } { ~~~~ ~~ ~~~~~~ { ROLLBACK } ~~~~~~~~ [ RECORD DELIMITER IS STANDARD-1 ] ~~~~~~ ~~~~~~~~~ ~~~~~~~~~~ [ RESERVE integer-1 AREAS ] ~~~~~~~ [ SHARING WITH { ALL OTHER } ] ~~~~~~~ } { ~~~ { NO OTHER } { ~~ } { READ ONLY } . ~~~~ ~~~~ The "COLLATING SEQUENCE", "RECORD DELIMITER", "RESERVE" and "ALL OTHER" clauses are syntactically recognized but are otherwise non-functional. ———————————————————————————————————————— 3 June 2014 Chapter 4 - ENVIRONMENT DIVISION 74 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide The "SELECT" statement creates a definition of a file and links that COBOL definition to the external operating system environment. 1. The reserved words "AREAS", "IS", "MODE", "OTHER", "SEQUENCE", "TO", "USING" and "WITH" are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program. 2. After , the various clauses may be coded in any sequence. 3. A period must follow the last coded clause. 4. The "OPTIONAL" clause, to be used only for files that will be used to provide input data to the program, indicates the file may or may not actually be available at run-time. Attempts to "OPEN" an "OPTIONAL" file when the file does not exist will receive a special non-fatal file status value (see status 05 in the list of file status values below) indicating the file is not available; a subsequent attempt to "READ" that file will return an "AT END" (end-of-file) condition. Optionally, files may be designated as "NOT OPTIONAL", if desired. This is useful when specifying the compiler’s "-foptional-file" switch, which automatically makes all files "OPTIONAL" except for those explicitly declared as "NOT OPTIONAL". 5. The value that you specify will be the name by which you will reference the file within your program. This name should be formed according to the rules for user-defined names (see [User-Defined Words], page 6). 6. The optional "ASSIGN" clause specifies how — at runtime, when is opened — either a logical device (STDIN, STDOUT) or a file anywhere in one of the currently-mounted filesystems will be associated with , as follows: A. There are three components to the "ASSIGN" clause — a <> specification ("EXTERNAL", "DYNAMIC" or neither), a <> (the list of device choices) and a <> (shown as a choice between , and ). B. "ASSIGN TO DISC ’’" will be assumed if there is no "ASSIGN" clause on a "SELECT". C. If an "ASSIGN" clause is coded without a <>, the device "DISC" will be assumed. D. If a <> clause is coded, the COBOL file will be attached to a data file within any filesystem that is mounted and available to the executing program at the time is opened. How that file is identified varies, depending upon the specified <>, as follows: a. If is coded, the value of the literal will serve as the File Location String that will identify the data file. b. If is coded, the value of the identifier will serve as the File Location String that will identify the data file. c. If (a syntactically valid word not duplicating that of a reserved Chapter 4 - ENVIRONMENT DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 75 or user-defined word) is coded, and a <> of "EXTERNAL" is specified, itself will serve as the File Location String that will identify the data file. If, however, a <> of "EXTERNAL" was not specified, the compiler will create a "PIC X(1024)" data item named within the program; the contents of that data item at the time the progrem opens will then serve as the File Location String that will identify the data file. d. File Location Strings will be discussed shortly. E. If no <> is coded, will be attached to a logical device or a file based upon the specified (or implied) <>, as follows: a. "DISC" or "DISK" will assume an attachment to a file named in whatever directory is current at the time the file is opened. b. "DISPLAY" will assume an attachment to the "STDOUT" logical device; these files should only be used for output. c. "KEYBOARD" will assume an attachment to the "STDIN" logical device; these files should only be used for input. d. "PRINTER" will assume an attachment to the "LPT1" logical device/port; these files should only be used for output. e. "RANDOM" or "TAPE" will behave exactly as "DISC" does. These two additional <>s are provided to facilitate the compilation of COBOL source from other COBOL implementations. F. The "LINE ADVANCING" device requires that a <> be specified; these files should only be used for output. A COBOL Line Advancing file will allow carriage- control characters such as line-feeds and form-feeds to be written to the attached operating system file, via the "ADVANCING" clause of the "WRITE" statement (see [WRITE], page 479). G. File Location Strings are used (at runtime) to identify the path and filename to the data file that must be attached to when that file is opened. H. If the compiler "config" file you used to compile the program with had a "filename- mapping" value of "yes", the GNU COBOL runtime system will first attempt to identify a currently-defined environment variable whose value will serve as the data file’s path and filename, as follows: a. If the compiler "config" file (see [Compiler Configuration Files], page 516) you used to compile the program specified "mf" as the "assign-clause" value, then the File Locator String will be interpreted according to Microfocus COBOL rules — namely, everything before the last "-" in the File Locator String will be ignored; the characters after the last "-" will be treated as the base of an environment variable name. If there is no "-" character in the File Locator String then the entire File Locator String will serve as the base of an environment variable name. This is the default behavior for every config file except "ibm". 3 June 2014 Chapter 4 - ENVIRONMENT DIVISION 76 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide b. If, on the other hand, the compiler "config" file you used to compile the program specified "mf" as the "assign-clause" value, then the File Locator String will be interpreted according to according to IBM COBOL rules — namely, the File Locator String is expected to be of theform "S-xxx" or "AS- xxx", in which case the "xxx" will be treated as the base of an environment variable name. If there is no "-" character in the File Locator String then the entire File Locator String will serve as the base of an environment variable name. c. Once an environment variable name base (let’s refer to it as "bbbb") has been determined, the runtime system will look for the first one of the following environment variables that exists, in this sequence: DD bbbb dd bbbb bbbb Windows systems are case-insensitive with regard to environment variables, so there is no difference between the first two when using a GNU COBOL implementation built for either Windows/MinGW or native Windows. If an environment variable was found, it’s value will serve as the path and filename to the data file. I. If no environment variable was found, or the "config" file used to compile the program had a "filename-mapping" value of "no", then the File Locator String value will serve as the path and filename to the data file. J. Paths and filenames may be specified on an absolute ("C:\Data\datafile.dat", relative-to-the-current-directory "/Data/datafile.dat", ("Data\datafile.dat", "Data/datafile.dat", . . . ) basis. . . . ) or There may not even be a path ("datafile.dat"), in which case the file must be in the current directory. 7. The "FILE STATUS" or "SORT STATUS" clause (they are both equivalent and only one or the other, if any, should be specified) is used to specify the name of a two-digit numeric data item into which an I/O status code will be saved after every I/O verb that is executed against the file. This does not actually allocate the data item — you must define the item yourself somewhere in the data division. Possible status codes that can be returned to a "FILE STATUS" data item are as follows: Code Explanation 00 02 05 07 Success Success (Duplicate Record Key Written) Success (Optional File Not Found) Success (No Unit) Chapter 4 - ENVIRONMENT DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 77 10 14 21 22 23 30 31 34 35 37 38 39 41 42 43 44 46 47 48 49 51 52 57 61 91 End of file reached if reading forward or beginning-of-file reached if reading backward Out of key range Key invalid Attempt to duplicate key value Key not found Permanent I/O error Inconsistent filename Boundary violation File not found Permission denied Closed with lock Conflicting attribute File already open File not open Read not done Record overflow Read error "OPEN INPUT" denied (insufficient permissions to read file) "OPEN OUTPUT" denied (insufficient permissions to write to file) "OPEN I-O" denied (insufficient permissions to read and/or write file) Record locked End of page "LINAGE" specifications invalid File sharing failure File not available 8. The "SHARING" clause defines the conditions under which the program will be willing (or not) to allow other programs executing at the same time to access the file. See [File Sharing], page 231, for the details. 9. The "LOCK" clause defines how concurrent access to the file will be managed on a record-by-record basis. See [Record Locking], page 233, for the details. 10. A "SELECT" statement without an "ORGANIZATION" explicitly coded will be handled as if the following ORGANIZATION clause had been specified: ORGANIZATION IS SEQUENTIAL ACCESS MODE IS SEQUENTIAL 3 June 2014 Chapter 4 - ENVIRONMENT DIVISION 78 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 4.2.1.1. ORGANIZATION SEQUENTIAL (cid:11) (cid:10) ORGANIZATION SEQUENTIAL Clause Syntax [ ORGANIZATION|ORGANISATION IS ] RECORD BINARY SEQUENTIAL ~~~~~~~~~~ ~~~~~~~~~~~~ ~~~~~~~~~~~~ [ ACCESS MODE IS SEQUENTIAL ] ~~~~~~ ~~~~~~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— Files declared as "ORGANIZATION SEQUENTIAL" will consist of records with no explicit end- of-record delimiter character sequences; records in such files are "delineated" by a calculated byte-offset (based on the maximum record length) into the file. 1. The reserved words "BINARY", "IS", "MODE" and "RECORD" are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program. 2. The reserved words "ORGANIZATION" and "ORGANISATION" are interchangeable. 3. The phrase "ORGANIZATION IS" (and it’s internationalized alternative, "ORGANISATION IS") is optional to provide compatibility with those (few) COBOL implementations that consider "ORGANIZATION" to be optional. Most COBOL implementations do re- quire the word "ORGANIZATION", so it should be used in new programs. 4. These files cannot be prepared with any standard text-editing or word processing soft- ware as all such programs will imbed delimiter characters at the end of records (use "ORGANIZATION IS LINE SEQUENTIAL" instead). 5. These files may contain either "USAGE DISPLAY" or "USAGE COMPUTATIONAL" (of any variety) data since no binary data sequence can be accidentally interpreted as an end- of-record delimiter. 6. While records in a "ORGANIZATION SEQUENTIAL" file may be defined as having variable- length records, the file will be structured in such a manner as to reserve space for each record equal to the size of the largest possible record, based on the file’s description in the "FILE SECTION". 7. The "ACCESS MODE SEQUENTIAL" clause is optional because, if absent, it will be as- sumed anyway for this type of file. The internal structure of these files is such that they can only be processed in a sequential manner; in order to read the 100th record in such a file, for example, you first must read records 1 through 99. 8. Sequential files are processed using the following statements: • "CLOSE" (see [CLOSE], page 364) • "COMMIT" (see [COMMIT], page 365) • "DELETE" (see [DELETE], page 369) Chapter 4 - ENVIRONMENT DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 79 • "MERGE" (see [MERGE], page 411) • "OPEN" (see [OPEN], page 420) • "READ" (see [READ], page 428) • "REWRITE" (see [REWRITE], page 437) • "SORT" (see [SORT], page 453) • "UNLOCK" (see [UNLOCK], page 474) • "WRITE" (see [WRITE], page 479) 3 June 2014 Chapter 4 - ENVIRONMENT DIVISION 80 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 4.2.1.2. ORGANIZATION LINE SEQUENTIAL (cid:11) (cid:10) ORGANIZATION LINE SEQUENTIAL Clause Syntax (cid:8) (cid:9) [ ORGANIZATION|ORGANISATION IS ] LINE SEQUENTIAL ~~~~ ~~~~~~~~~~ ~~~~~~~~~~~~ ~~~~~~~~~~~~ [ ACCESS MODE IS SEQUENTIAL ] ~~~~~~ ~~~~~~~~~~ [ PADDING CHARACTER IS literal-1 | identifier-1 ] ~~~~~~~ The "PADDING CHARACTER" clause non-functional. is syntactically recognized but is otherwise ———————————————————————————————————————— Files declared as "ORGANIZATION LINE SEQUENTIAL" will consist of records terminated by an end-of-record delimiter character or character sequence. 1. The reserved words "CHARACTER", "IS" and "MODE" are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program. 2. The reserved words "ORGANIZATION" and "ORGANISATION" are interchangeable. 3. The phrase "ORGANIZATION IS" (and it’s internationalized alternative, "ORGANISATION IS") is optional to provide compatibility with those (few) COBOL implementations that consider that word to be optional. Most COBOL implementations do require the word "ORGANIZATION", so it should be used in new programs. 4. This is the only "ORGANIZATION" valid for files that are assigned to the "PRINTER" device. 5. These files may be created with any standard text-editing or word processing software capable of writing text files. Such files should not contain any "USAGE COMPUTATIONAL" or "BINARY" (of any variety) data since such fields could accidentally contain byte sequences that could be interpreted as an end-of-record delimiter. 6. Both fixed- and variable-length record formats are supported. 7. The end-of-record delimiter sequence will be X’0A’ (an ASCII line-feed character) or a X’0D0A’ (an ASCII carriage-return + line-feed sequence). The former is used on Unix implementations of GNU COBOL (including Windows/MinGW, Windows/Cygwin and OSX implementations) while the latter would be used with native Windows implemen- tations. 8. When reading a "LINE SEQUENTIAL" file, records in excess of the size implied by the file’s description in the "FILE SECTION" will be truncated while records shorter than that size will be padded to the right with "SPACES". Chapter 4 - ENVIRONMENT DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 81 9. The "ACCESS MODE SEQUENTIAL" clause is optional because, if absent, it will be as- sumed anyway for this type of file. The internal structure of these files is such that the data can only be processed in a sequential manner; in order to read the 100th record in such a file, for example, you first must read records 1 through 99. 10. Files assigned to "PRINTER" or "CONSOLE" should be specified as "ORGANIZATION LINE SEQUENTIAL". 11. Line Sequential files are processed using the following statements: • "CLOSE" (see [CLOSE], page 364) • "COMMIT" (see [COMMIT], page 365) • "DELETE" (see [DELETE], page 369) • "MERGE" (see [MERGE], page 411) • "OPEN" (see [OPEN], page 420) • "READ" (see [READ], page 428) • "REWRITE" (see [REWRITE], page 437) • "SORT" (see [SORT], page 453) • "UNLOCK" (see [UNLOCK], page 474) • "WRITE" (see [WRITE], page 479) 3 June 2014 Chapter 4 - ENVIRONMENT DIVISION 82 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 4.2.1.3. ORGANIZATION RELATIVE (cid:11) (cid:10) ORGANIZATION RELATIVE Clause Syntax (cid:8) (cid:9) [ ORGANIZATION|ORGANISATION IS ] RELATIVE ~~~~~~~~ ~~~~~~~~~~~~ ~~~~~~~~~~~~ [ ACCESS MODE IS { SEQUENTIAL } ] ~~~~~~ { ~~~~~~~~~~ } } { DYNAMIC } { ~~~~~~~ { RANDOM } ~~~~~~ [ RELATIVE KEY IS identifier-1 ] ~~~~~~~~ ———————————————————————————————————————— These files are files with an internal organization such that records may be processed in a sequential manner based upon their physical location in the file or in a random manner by allowing records to be read, written or updated by specifying the relative record number in the file. 1. The reserved words "IS", "KEY" and "MODE" are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program. 2. The reserved words "ORGANIZATION" and "ORGANISATION" are interchangeable. 3. The phrase "ORGANIZATION IS" (and it’s internationalized alternative, "ORGANISATION IS") is optional to provide compatibility with those (few) COBOL implementations that consider that word to be optional. Most COBOL implementations do require the word "ORGANIZATION", so it should be used in new programs. 4. "ORGANIZATION RELATIVE" files cannot be assigned to the "CONSOLE", "DISPLAY", "LINE ADVANCING" or "PRINTER" devices. 5. The "RELATIVE KEY" clause is optional only if "ACCESS MODE SEQUENTIAL" is specified. 6. While an "ORGANIZATION RELATIVE" file may be defined as having variable-length records, the file will be structured in such a manner as to reserve space for each record equal to the size of the largest possible record as defined by the file’s description in the "FILE SECTION". 7. "ACCESS MODE SEQUENTIAL", the default "ACCESS MODE" if none is specified, indicates that the records of the file will be processed in a sequential manner, according to their physical sequence in the file. 8. "ACCESS MODE RANDOM" means that records will be processed in random sequence by specifying their record number in the file every time the file is read or written. Chapter 4 - ENVIRONMENT DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 83 9. "ACCESS MODE DYNAMIC" indicates the program may switch back and forth between "SEQUENTIAL" and "RANDOM" mode during execution. The file starts out initially in "SEQUENTIAL" mode when first opened but the program may use the "START" statement (see [START], page 459) to switch between sequential and random access. 10. The "RELATIVE KEY" data item is a numeric data item that cannot be defined as a field within records of this file. Its purpose is to return the current relative record number of a relative file that is being processed in "SEQUENTIAL" access mode and to serve as a key that specifies the relative record number to be read or written when processing a relative file in "RANDOM" access mode. 11. Relative files are processed using the following statements: • "CLOSE" (see [CLOSE], page 364) • "COMMIT" (see [COMMIT], page 365) • "DELETE" (see [DELETE], page 369) • "MERGE" (see [MERGE], page 411), "ACCESS MODE RANDOM" not allowed • "OPEN" (see [OPEN], page 420) • "READ" (see [READ], page 428) • "REWRITE" (see [REWRITE], page 437) • "SORT" (see [SORT], page 453), "ACCESS MODE RANDOM" not allowed • "START" (see [START], page 459) • "UNLOCK" (see [UNLOCK], page 474) • "WRITE" (see [WRITE], page 479) 3 June 2014 Chapter 4 - ENVIRONMENT DIVISION 84 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 4.2.1.4. ORGANIZATION INDEXED (cid:11) (cid:10) ORGANIZATION INDEXED Clause Syntax (cid:8) (cid:9) [ ORGANIZATION|ORGANISATION IS ] INDEXED ~~~~~~~ ~~~~~~~~~~~~ ~~~~~~~~~~~~ [ ACCESS MODE IS { SEQUENTIAL } ] ~~~~~~ { ~~~~~~~~~ } } { DYNAMIC } { ~~~~~~~ { RANDOM } ~~~~~~ [ RECORD KEY IS identifier-1 ~~~~~~ [ =|{SOURCE IS} identifier-2 ] ] ~~~~~~ [ ALTERNATE RECORD KEY IS identifier-3 ~~~~~~~~~ ~~~~~~ [ =|{SOURCE IS} identifier-4 ] ~~~~~~ [ WITH DUPLICATES ] ]... ~~~~~~~~~~ The "SOURCE" clause is syntactically recognized but is otherwise non-functional. It is sup- ported to provide compatibility with COBOL source written for other COBOL implemen- tations. ———————————————————————————————————————— Indexed files, like relative files, may have their records processed in either a sequential or random manner. Unlike relative files, however, the actual location of a record in an indexed file is calculated automatically based upon the value(s) of one or more alphanumeric fields within records of the file. For example, an indexed file containing product data might use the product identification code as a record key. This means you may read, write or update the "A6G4328"th record or the "Z8X7723"th record directly, based upon the product id value of those records! 1. The reserved words "IS", "KEY" and "MODE" are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program. 2. The reserved words "ORGANIZATION" and "ORGANISATION" are interchangeable. 3. The phrase "ORGANIZATION IS" (and it’s internationalized alternative, "ORGANISATION IS") is optional to provide compatibility with those (few) COBOL implementations that consider that word to be optional. Most COBOL implementations do require the word "ORGANIZATION", so it should be used in new programs. Chapter 4 - ENVIRONMENT DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 85 4. "ORGANIZATION INDEXED" files cannot be assigned to "CONSOLE", "DISPLAY", "KEYBOARD", "LINE ADVANCING" or "PRINTER". 5. "ACCESS MODE SEQUENTIAL", the default "ACCESS MODE" if none is specified, indicates that the records of the file will be processed in a sequential manner with respect to the values of the "RECORD KEY" or the "ALTERNATE RECORD KEY" most-recently referenced on a "START" statement (see [START], page 459). 6. "ACCESS MODE RANDOM" means that records will be processed in random sequence by accessing the record with specific record key or alternate record key values. 7. "ACCESS MODE DYNAMIC" allows the file will be processed either in "RANDOM" or "SEQUENTIAL" mode; the program may switch between the two modes as needed. The "START" statement is used to make the switch between modes. 8. The "PRIMARY KEY" clause defines the field within the record used to provide the primary access to records within the file. No two records in the file will be allowed to have the same "PRIMARY KEY" field value. 9. The "ALTERNATE RECORD KEY" clause, if used, defines an additional field within the record that provides an alternate means of directly accessing records or an additional field by which the file’s contents may be processed sequentially. You have the choice of allowing records to have duplicate alternate key values, if necessary. 10. There may be multiple "ALTERNATE RECORD KEY" clauses, each defining an additional alternate key for the file. 11. Indexed files are processed using the following statements: • "CLOSE" (see [CLOSE], page 364) • "COMMIT" (see [COMMIT], page 365) • "DELETE" (see [DELETE], page 369) • "MERGE" (see [MERGE], page 411), "ACCESS MODE RANDOM" not allowed • "OPEN" (see [OPEN], page 420) • "READ" (see [READ], page 428) • "REWRITE" (see [REWRITE], page 437) • "SORT" (see [SORT], page 453), "ACCESS MODE RANDOM" not allowed • "START" (see [START], page 459) • "UNLOCK" (see [UNLOCK], page 474) • "WRITE" (see [WRITE], page 479) 3 June 2014 Chapter 4 - ENVIRONMENT DIVISION 86 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 4.2.2. MULTIPLE FILE (cid:11) (cid:10) I-O-CONTROL MULTIPLE FILE Syntax MULTIPLE FILE TAPE CONTAINS ~~~~~~~~ { file-name-1 [ POSITION integer-1 ] }... ~~~~~~~~ . (cid:8) (cid:9) The "MULTIPLE FILE TAPE" clause is obsolete and is therefore recognized but not func- tional. ———————————————————————————————————————— Chapter 4 - ENVIRONMENT DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 87 4.2.3. SAME RECORD AREA (cid:11) (cid:10) I-O-CONTROL SAME AREA Syntax SAME { SORT-MERGE } AREA FOR file-name-1... ~~~~ { ~~~~~~~~~~ } } } } { SORT { ~~~~ { RECORD ~~~~~~ . (cid:8) (cid:9) The "SAME SORT-MERGE" and "SAME SORT" clauses are syntactically recognized but are otherwise non-functional. ———————————————————————————————————————— The "SAME RECORD AREA" clause allows you to specify that multiple files should share the same input and output memory buffers. 1. The reserved words "AREA" and "FOR" are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program. 2. This statement must be terminated with a period. 3. While coding only a single file name (the repeated item) is syntactically valid, this statement will have no effect upon the program unless at least two files are specified. 4. The effect of this statement will be to cause the specified files to share the same I/O buffer in memory. These buffers can sometimes get quite large, and by having multiple files share the same buffer memory you may significantly cut down the amount of memory the program is using (thus making "room" for more procedural code or data). If you do use this feature, take care to ensure that no more than one of the specified files are ever OPEN simultaneously. ———————————————————— End of Chapter 4 — ENVIRONMENT DIVISION 3 June 2014 Chapter 4 - ENVIRONMENT DIVISION GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 89 5. DATA DIVISION (cid:11) (cid:10) DATA DIVISION Syntax (cid:8) (cid:9) DATA DIVISION. ~~~~ ~~~~~~~~ [ FILE SECTION. ~~~~ ~~~~~~~ { File/Sort-Description [ { FILE-SECTION-Data-Item } ]... { { { 01-Level-Constant { 78-Level-Constant { 01-Level-Constant { 78-Level-Constant } } ] }... } } } } [ WORKING-STORAGE SECTION. ~~~~~~~~~~~~~~~ ~~~~~~~ [ { WORKING-STORAGE-SECTION-Data-Item } ]... ] { 01-Level-Constant { 78-Level-Constant } } [ LOCAL-STORAGE SECTION. ~~~~~~~~~~~~~ ~~~~~~~ [ { LOCAL-STORAGE-SECTION-Data-Item } ]... ] { 01-Level-Constant { 78-Level-Constant } } [ LINKAGE SECTION. ~~~~~~~ ~~~~~~~ [ { LINKAGE-SECTION-Data-Item } ]... ] { 01-Level-Constant { 78-Level-Constant } } [ REPORT SECTION. ~~~~~~ ~~~~~~~ { Report-Description [ { Report-Group-Definition } ]... { { { 01-Level-Constant { 78-Level-Constant { 01-Level-Constant { 78-Level-Constant } } ] }... } } } } [ SCREEN SECTION. ~~~~~~ ~~~~~~~ [ { SCREEN-SECTION-Data-Item } ]... ] { 01-Level-Constant { 78-Level-Constant } } ———————————————————————————————————————— All data used by any COBOL program must be defined in one of the six sections of the data division, depending upon the purpose of the data. 3 June 2014 Chapter 5 - DATA DIVISION 90 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 1. If no data will be described in one of the data division sections, that section header may be omitted. 2. If no data division sections are needed, the "DATA DIVISION." header itself may be omitted. 3. If more than one section is needed in the data division (a common situation), the sections must be coded in the sequence they are presented above. 5.1. Data Definition Principles GNU COBOL data items, like those of other COBOL implementations, are described in a hierarchical manner. This accommodates the fact that data items frequently need to be able to be broken up into subordinate items. Take for example, the following logical layout of a portion of a data item named "Employee": The "Employee" data item consists of two subordinate data items — an "Employee-Name" and an "Employment-Dates" data item (presumably there would be a lot of others too, but we don’t care about them right now). As the diagram shows, each of those data items are, in turn, broken down into subordinate data items. This hierarchy of data items can get rather "deep", and GNU COBOL, like other COBOL implementations, can handle up to 49 levels of such hierarchical structures. As was presented earlier (see [Structured Data], page 10), a data item that is broken down into other data items is referred to as a group item, while one that isn’t broken down is called an elementary item. COBOL uses the concept of a "level number" to indicate the level at which a data item occurs in a data structure such as the example shown above. When these data items are defined, they are all defined together with a number in the range 1-49 specified in front of their names. Over the years, a convention has come to exist among COBOL programmers that level numbers are always coded as two-digit numbers — they don’t have to be specified as two-digit numbers, but every example you see in this document will take that approach! Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 91 The data item at the top, also referred to as a "record", always has a level number of 01. After that, you may assign level numbers as you wish (01–02–03–04. . . , 01–05–10–15. . . , etc.), as long as you follow these simple rules: 1. Every data item at the same "level" of a hierarchy diagram such as the one you see here (if you were to make one, which you rarely — if ever — will, once you get used to this concept) must have the same level number. 2. Every new level uses a level number that is strictly greater than the one used in the parent (next higher) level. 3. When describing data hierarchies, you may never use a level number greater than 49 (except for 66, 77, 78 and 88 which have very special meanings — see see [Special Data Items], page 118). So, the definition of these data items in a GNU COBOL program would go something like this: 01 Employee 05 Employee-Name 10 Last-Name 10 First-Name 10 Middle-Initial 05 Employment-Dates 10 From-Date 15 Year 15 Month 15 Day 10 To-Date 15 Year 15 Month 15 Day The indentation is purely at the discretion of the programmer to make things easier for humans to read (the compiler couldn’t care less). Historically, COBOL implementations that required Fixed Format Mode source programs required that the "01" level number begin in Area A and that everything else begins in Area B. GNU COBOL only requires that all data definition syntax occur in columns 8-72. In Free Format Mode, of course, there aren’t even those limitations. Did you notice that there are two each of "Year", "Month" and "Day" data names defined? Thet’s perfectly legal, provided that each can be uniquely "qualified" so as to be dis- tinct from the other. Take for example the "Year" items. One is defined as part of the "From-Date" data item while the other is defined as part of the "To-Date" data item. In COBOL, we would actually code references to these two data items as either "Year OF From-Date" and "Year OF To-Date" or "Year IN From-Date" and "Year IN To-Date" (COBOL allows either "IN" or "OF" to be used). Since these references would clarify any 3 June 2014 Chapter 5 - DATA DIVISION 92 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide confusion to us as to which "Year" might be referenced, the GNU COBOL compiler won’t be confused either. The coding example shown above is incomplete — it only describes the data item names and their hierarchical relationships to one other. In addition, any valid data item definitions will also need to describe what type of data is to be contained in a data item (Numeric? Alphanumeric? Alphabetic?), how much data can be held in the data item and a multitude of other characteristics. When group items are being defined, subordinate items may be assigned a "name" of "FILLER". There may be any number of "FILLER" items defined within a group item. A data item named "FILLER" cannot be referenced directly; these items are generally used to specify an unused portion of the total storage allocated to a group item. Note that it is possible that the name of the group item itself might be specified as "FILLER" if there is no need to ever refer directly to the group structure itself. Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 93 5.2. FILE SECTION (cid:11) (cid:10) FILE SECTION Syntax (cid:8) (cid:9) [ FILE SECTION. ~~~~ ~~~~~~~ { File/Sort-Description [ { FILE-SECTION-Data-Item } ]... { { { 01-Level-Constant { 78-Level-Constant { 01-Level-Constant { 78-Level-Constant } } }... ] } } } } ———————————————————————————————————————— Every file that has been referenced by a "SELECT" statement (see [SELECT], page 73) must also be described in the file section of the data division. Files destined for use as sort/merge work files must be described with a Sort/Merge File Description ("SD") while every other file is described with a File Description ("FD"). Each of these descriptions will almost always be followed with at least one record description. 3 June 2014 Chapter 5 - DATA DIVISION 94 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 5.2.1. File/Sort-Description (cid:11) (cid:10) File/Sort-Description Syntax (cid:8) (cid:9) FD|SD file-name-1 [ IS EXTERNAL|GLOBAL ] ~~ ~~ [ BLOCK CONTAINS [ integer-1 TO ] integer-2 CHARACTERS|RECORDS ] ~~~~~~~~ ~~~~~~ ~~~~~~~~~~ ~~~~~~~ ~~~~~ ~~ [ CODE-SET IS alphabet-name-1 ] ~~~~~~~~ [ DATA { RECORD IS ~~~~ { ~~~~~~ } identifier-1... } { RECORDS ARE } ] ~~~~~~~ [ LABEL { RECORD IS ~~~~~ { ~~~~~~ } OMITTED|STANDARD ] } ~~~~~~~ ~~~~~~~~ { RECORDS ARE } ~~~~~~~ [ LINAGE IS integer-3 | identifier-2 LINES ~~~~~~ [ LINES AT BOTTOM integer-4 | identifier-3 ] ~~~~~~ [ LINES AT TOP integer-5 | identifier-4 ] ~~~ [ WITH FOOTING AT integer-6 | identifier-5 ] ] ~~~~~~~ ~~~~~~ { [ RECORD { CONTAINS [ integer-7 TO ] integer-8 CHARACTERS ~~ } ] } } } [ FROM [ integer-7 TO ] integer-8 CHARACTERS } } } { IS VARYING IN SIZE { { { { ~~~~~~~ ~~ DEPENDING ON identifier-6 ] ~~~~~~~~~ [ RECORDING MODE IS recording-mode ] ~~~~~~~~~ } report-name-1... ] [ { REPORT IS { ~~~~~~ } { REPORTS ARE } ~~~~~~~ [ VALUE OF implementor-name-1 IS literal-1 | identifier-7 ] . ~~~~~ ~~ Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 95 The "BLOCK CONTAINS", "DATA RECORD", "LABEL RECORD", "RECORDING MODE" and "VALUE OF" clauses are syntactically recognized but are obsolete and non-functional. These clauses should not be coded in new programs. ———————————————————————————————————————— 1. The reserved words "ARE", "AT", "CHARACTERS" ("RECORD" clause only), "CONTAINS", "FROM", "IN", "IS", "ON" and "WITH" are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program. 2. The terms "RECORD IS" and "RECORDS ARE" are interchangeable. 3. The terms "REPORT IS" and "REPORTS ARE" are interchangeable. 4. Only files intended for use as work files for either the "SORT" (see [SORT], page 453) or "MERGE" (see [MERGE], page 411) statements should be coded with an SD — all others should be defined with a FD. 5. The sequence in which files are defined via "FD" or "SD", as compared to the sequence in which their "SELECT" statements were coded, is irrelevant. 6. The name specified as must exactly match the name specified on the file’s "SELECT" statement. 7. The "CODE-SET" clause allows a custom alphabet, defined in the "SPECIAL-NAMES" (see [SPECIAL-NAMES], page 62) paragraph, to be associated with a file. This clause is valid only when used with sequential or line sequential files. 8. The "LINAGE" clause may only be specified in the "FD" of a sequential or line sequential file. If used with a sequential file, the organization of that file will be implicitly changed to line sequential. The various components of the "LINAGE" clause define the layout of printed pages as follows: • "LINES AT TOP" — the number of unused (i.e. left blank) lines at the top of every page. The default if this if not specified is zero. • "LINES AT BOTTOM" — the number of unused (i.e. left blank) lines at the bottom of every page. The default if this if not specified is zero. • "LINAGE IS n LINES" — the total number of used/usable lines on the page. • The sum of the previous three specifications should be the total number of possible lines available on one printed page. • "FOOTING AT" — the line number beyond which nothing may be printed except for any footing that is to appear on every page. The default for this if not specified is zero, meaning there will be no footings. This value cannot be larger than the "LINAGE IS n LINES" value. 9. This page structure — once defined — can be automatically enforced by the "WRITE" statement (see [WRITE], page 479). 3 June 2014 Chapter 5 - DATA DIVISION 96 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 10. Specifying a "LINAGE" clause in an "FD" will cause the "LINAGE-COUNTER" special register to be created for the file. This automatically-created data item will always contain the current relative line number on the page being prepared which will serve as the starting point for a "WRITE" statement. 11. The "RECORD CONTAINS" and "RECORD IS VARYING" clauses are ignored (with a warn- ing message issued) when used with line sequential files. With other file organizations, these mutually-exclusive clauses define the length of data records within the file. The data item specified as must be defined within one of the record descrip- tions of . 12. The "REPORT IS" clause announces to the compiler that the file will be dedicated to the Report Writer Control System (RWCS); the clause names one or more reports, each to be described in the report section. The following special rules apply when the "REPORT" clause is used: A. The clause may only be specified in the "FD" of a sequential or line sequential file. If used with a sequential file, the organization of that file will be implicitly changed to line sequential. B. The "FD" cannot be followed by record descriptions — detailed descriptions of data to be printed to the file will be defined in the "REPORT SECTION" (see [REPORT SECTION], page 107). C. If a "LINAGE" clause is also specified, Values specified for "LINAGE IS" and "FOOTING AT" will be ignored. The values of "LINES AT BOTTOM" and "LINES AT TOP", if any, will be honored. 13. The following special rules apply only to sort/merge work files: A. Sort/merge work files should be assigned to "DISK" (or "DISC") on their "SELECT" statements. B. Sorts and merges will be performed in memory, if the amount of data being sorted allows. C. Should actual disk work files be necessary due to the amount of data being sorted or merged, they will be automatically allocated to disk in a folder defined by: • The "TMPDIR" run-time environment variable (see [Run Time Environment Variables], page 522) • The "TMP" run-time environment variable • The "TEMP" run-time environment variable (in that order) D. These disk files will be automatically purged upon "SORT" or "MERGE" termination. They will also be purged if the program terminates abnormally before the "SORT" or "MERGE" finishes. Should you ever need to know, temporary sort/merge work files will be named "cob*.tmp". Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 97 E. If you specify a specific filename in the sort/merge work file’s "SELECT", it will be ignored. 14. See [Data Description Clauses], page 125, for information on the "EXTERNAL" and "GLOBAL" options. 3 June 2014 Chapter 5 - DATA DIVISION 98 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 5.2.2. FILE-SECTION-Data-Item (cid:11) (cid:10) FILE-SECTION-Data-Item Syntax (cid:8) (cid:9) level-number [ identifier-1 | FILLER ] [ IS GLOBAL|EXTERNAL ] ~~~~~~ ~~~~~~ ~~~~~~~~ [ BLANK WHEN ZERO ] ~~~~~ ~~~~ [ JUSTIFIED RIGHT ] ~~~~ [ OCCURS [ integer-1 TO ] integer-2 TIMES ~~~~~~ ~~ [ DEPENDING ON identifier-2 ] ~~~~~~~~~ [ ASCENDING|DESCENDING KEY IS identifier-3 ] ~~~~~~~~~ ~~~~~~~~~~ [ INDEXED BY identifier-4 ] ] ~~~~~~~ [ PICTURE IS picture-string ] ~~~ [ REDEFINES identifier-5 ] ~~~~~~~~~ [ SIGN IS LEADING|TRAILING [ SEPARATE [CHARACTER] ] ] ~~~~ ~~~~~~~ ~~~~~~~~ ~~~~~~~~ [ SYNCRONIZED|SYNCHRONISED [ LEFT|RIGHT ] ] ~~~~ ~~~~ ~~~~ ~~~~~ [ USAGE IS data-item-usage ] . [ FILE-SECTION-Data-Item ]... ~~~~~ The "LEFT" and "RIGHT" (SYNCRONIZED) clauses are syntactically recognized but are otherwise non-functional. ———————————————————————————————————————— Every sort file description ("SD" or "FD") must be followed by at least one 01-level data item, except for file descriptions containing the "REPORT IS" clause. These 01-level data items, in turn, may be broken down into subordinate group and elementary items. An 01-level data item defined here in the file section is also known as a ’Record ’, even if it is an elementary item, provided that elementary item lacks the "CONSTANT" attribute. 1. The reserved words "BY", "IS", "KEY", "ON" and "WHEN" are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program. 2. The reserved words "SYNCRONIZED" and "SYNCRONIZED" are interchangeable. Both may be abbreviated to "SYNC". Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 99 3. The reserved word "PICTURE" may be abbreviated to "PIC". 4. As the syntax diagram shows, the definition of a <> is a recursive one in that there may be any number of such specifications coded following a FD or SD. The first such specification must have a level number of 01, and will describe a specific format of data record within the file. Specifications that follow that one may have level numbers greater than 01, in which case they are defining a hierarchical breakdown of the record. The definition of a record is terminated when one of the following occurs: • Another 01-level item is found — this signifies the start of another record layout for the file. • Another "FD" or "SD" is found — this marks the completion of the detailed de- scription of the file and begins another. • A division or section header is found — this also marks the completion of the detailed description of the file and signifies the end of the file section as well. 5. Every <> description must be terminated with a period. 6. If there are multiple record descriptions present for a given "FD" or "SD", the one with the longest length will define the size of the record buffer into which a "READ" statement (see [READ], page 428) or a "RETURN" statement (see [RETURN], page 436) will deliver data read from the file and from which a "WRITE" statement (see [WRITE], page 479) or "RELEASE" statement (see [RELEASE], page 434) statement will obtain the data to be written to the file. 7. The various 01-level record descriptions for a file description implicitly share that one common record buffer (thus, they provide different ways to view the structure of data that can exist within the file). Record buffers can be shared between files by using the "SAME RECORD AREA" (see [SAME RECORD AREA], page 87) clause. 8. The only valid level numbers are 01-49, 66, 77, 78 and 88. Level numbers 66, 77, 78 and 88 all have special uses — See [Special Data Items], page 118, for details. 9. Not specifying an or "FILLER" immediately after the level number has the same effect as if "FILLER" were specified. A data item named "FILLER" cannot be referenced directly; these items are generally used to specify an unused portion of the total storage allocated to a group item or to describe a group item whose contents which will only be referenced using the names of those items that belong to it. 10. "EXTERNAL" cannot be combined with "GLOBAL" or "REDEFINES". 11. File section data buffers (and therefore all 01-level record layouts defined in the file section) are initialized to all binary zeros when the program is loaded into storage. 12. See [Data Description Clauses], page 125, for information on the usage of the various data description clauses. 3 June 2014 Chapter 5 - DATA DIVISION 100 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 5.3. WORKING-STORAGE SECTION (cid:11) (cid:10) WORKING-STORAGE-SECTION-Data-Item Syntax level-number [ identifier-1 | FILLER ] [ IS GLOBAL | EXTERNAL ] ~~~~~~ ~~~~~~ ~~~~~~~~ (cid:8) (cid:9) [ BASED ] ~~~~~ [ BLANK WHEN ZERO ] ~~~~~ ~~~~ [ JUSTIFIED RIGHT ] ~~~~ [ OCCURS [ integer-1 TO ] integer-2 TIMES ~~~~~~ ~~ [ DEPENDING ON identifier-2 ] ~~~~~~~~~ [ ASCENDING|DESCENDING KEY IS identifier-3 ] ~~~~~~~~~ ~~~~~~~~~~ [ INDEXED BY identifier-4 ] ] ~~~~~~~ [ PICTURE IS picture-string ] ~~~ [ REDEFINES identifier-5 ] ~~~~~~~~~ [ SIGN IS LEADING|TRAILING [ SEPARATE CHARACTER ] ] ~~~~ ~~~~~~~ ~~~~~~~~ ~~~~~~~~ [ SYNCRONIZED|SYNCHRONISED [ LEFT|RIGHT ] ] ~~~~ ~~~~ ~~~~ ~~~~~ [ USAGE IS data-item-usage ] ~~~~~ [ VALUE IS [ ALL ] literal-1 ] . [ WORKING-STORAGE-SECTION-Data-Item ]... ~~~~~ ~~~ The "LEFT" and "RIGHT" (SYNCRONIZED) clauses are syntactically recognized but are otherwise non-functional. ———————————————————————————————————————— The working-storage section is used to describe data items that are not part of files, screens or reports and whose data values persist throughout the execution of the program. 1. The reserved words "BY", "CHARACTER", "IS", "KEY", "ON", "RIGHT" (JUSTIFIED), "TIMES" and "WHEN" are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program. 2. The reserved words "SYNCRONIZED" and "SYNCRONISED" are interchangeable. Both may be abbreviated as "SYNC". Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 101 3. The reserved word "PICTURE" may be abbreviated to "PIC". 4. The reserved word "JUSTIFIED" may be abbreviated to "JUST". 5. As the syntax diagram shows, the definition of a <> is a recursive one in that there may be any number of such specifications coded following one another. The first such specification must have a level number of 01. Specifications that follow that one may have level numbers greater than 01, in which case they are defining a hierarchical breakdown of a record. The definition of a record is terminated when one of the following occurs: • Another 01-level item is found — this signifies the end of the definition of one record and the start of a another. • A 77-level item is found — this signifies the end of the definition of the record and begins the definition of a special data item; See [77-Level Data Items], page 122, for more information. • A division or section header is found — this also marks the completion of a record and signifies the end of the working-storage section as well. 6. Every <> description must be termi- nated with a period. 7. The only valid level numbers are 01-49, 66, 77, 78 and 88. Level numbers 01 through 49 are used to define data items that may be part of a hierarchical structure. Level number 01 can also be used to define a constant — an item with an unchangable value specified at compilation time. 8. Level numbers 66, 77, 78 and 88 all have special uses — See [Special Data Items], page 118, for details. 9. Not specifying an or "FILLER" immediately after the level number has the same effect as if "FILLER" were specified. A data item named "FILLER" cannot be referenced directly; these items are generally used to specify an unused portion of the total storage allocated to a group item or to describe a group item whose contents which will only be referenced using the names of those items that belong to it. 10. Data items defined within the working-storage section are automatically initialized once — as the program in which the data is defined is loaded into memory. Subprograms may be loaded into memory more than once (see the "CANCEL" statement (see [CANCEL], page 363)), in which case initialization will happen each time they are loaded. See [Data Initialization], page 23, for a discussion of the initialization rules. 11. See [Data Description Clauses], page 125, for information on the usage of the various data description clauses. 3 June 2014 Chapter 5 - DATA DIVISION 102 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 5.4. LOCAL-STORAGE SECTION (cid:11) (cid:10) LOCAL-STORAGE-SECTION-Data-Item Syntax (cid:8) (cid:9) level-number [ identifier-1 | FILLER ] [ IS GLOBAL|EXTERNAL ] ~~~~~~ ~~~~~~ ~~~~~~~~ [ BASED ] ~~~~~ [ BLANK WHEN ZERO ] ~~~~~ ~~~~ [ JUSTIFIED RIGHT ] ~~~~ [ OCCURS [ integer-1 TO ] integer-2 TIMES ~~~~~~ ~~ [ DEPENDING ON identifier-2 ] ~~~~~~~~~ [ ASCENDING|DESCENDING KEY IS identifier-3 ] ~~~~~~~~~ ~~~~~~~~~~ [ INDEXED BY identifier-4 ] ] ~~~~~~~ [ PICTURE IS picture-string ] ~~~ [ REDEFINES identifier-5 ] ~~~~~~~~~ [ SIGN IS LEADING|TRAILING [ SEPARATE CHARACTER ] ] ~~~~ ~~~~~~~ ~~~~~~~~ ~~~~~~~~ [ SYNCRONIZED|SYNCHRONISED [ LEFT|RIGHT ] ] ~~~~ ~~~~ ~~~~ ~~~~~ [ USAGE IS data-item-usage ] ~~~~~ [ VALUE IS [ ALL ] literal-1 ] . [ LOCAL-STORAGE-SECTION-Data-Item ]... ~~~~~ ~~~ The "LEFT" and "RIGHT" (SYNCRONIZED) clauses are syntactically recognized but are otherwise non-functional. ———————————————————————————————————————— The local-storage section is similar to working-storage, but describes data within a sub- program that will be dynamically allocated and initialized (automatically) each time the subprogram is executed. See [Data Initialization], page 23, for the rules of data ititialization. 1. The reserved words "BY", "CHARACTER" "IS", "KEY", "ON", "RIGHT" (JUSTIFIED), "TIMES" and "WHEN" are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program. Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 103 2. The reserved words "SYNCRONIZED" and "SYNCRONISED" are interchangeable. Both may be abbreviated as "SYNC". 3. The reserved word "PICTURE" may be abbreviated to "PIC". 4. The reserved word "JUSTIFIED" may be abbreviated to "JUST". 5. As the syntax diagram shows, the definition of a <> is a recursive one in that there may be any number of such specifications coded following one another. The first such specification must have a level number of 01. Specifications that follow that one may have level numbers greater than 01, in which case they are defining a hierarchical breakdown of a record. The definition of a record is terminated when one of the following occurs: • Another 01-level item is found — this signifies the end of the definition of one record and the start of a another. • A division or section header is found — this also marks the completion of a record and signifies the end of the local-storage section as well. 6. Every <> description must be terminated with a period. 7. The only valid level numbers are 01-49, 66, 77, 78 and 88. Level numbers 01 through 49 are used to define data items that may be part of a hierarchical structure. Level number 01 can also be used to define a constant — an item with an unchangable value specified at compilation time. 8. Level numbers 66, 77, 78 and 88 all have special uses — See [Special Data Items], page 118, for details. 9. Not specifying an or "FILLER" immediately after the level number has the same effect as if "FILLER" were specified. A data item named "FILLER" cannot be referenced directly; these items are generally used to specify an unused portion of the total storage allocated to a group item or to describe a group item whose contents which will only be referenced using the names of those items that belong to it. 10. Local-storage cannot be used in nested subprograms. 11. See [Data Description Clauses], page 125, for information on the usage of the various data description clauses. 3 June 2014 Chapter 5 - DATA DIVISION 104 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 5.5. LINKAGE SECTION (cid:11) (cid:10) LINKAGE-SECTION-Data-Item Syntax level-number [ identifier-1 | FILLER ] [ IS GLOBAL|EXTERNAL ] ~~~~~~ ~~~~~~ ~~~~~~~~ (cid:8) (cid:9) [ ANY LENGTH ] ~~~ ~~~~~~ [ BASED ] ~~~~~ [ BLANK WHEN ZERO ] ~~~~~ ~~~~ [ JUSTIFIED RIGHT ] ~~~~ [ OCCURS [ integer-1 TO ] integer-2 TIMES ~~~~~~ ~~ [ DEPENDING ON identifier-3 ] ~~~~~~~~~ [ ASCENDING|DESCENDING KEY IS identifier-4 ] ~~~~~~~~~ ~~~~~~~~~~ [ INDEXED BY identifier-5 ] ] ~~~~~~~ [ PICTURE IS picture-string ] ~~~ [ REDEFINES identifier-6 ] ~~~~~~~~~ [ SIGN IS LEADING|TRAILING [ SEPARATE CHARACTER ] ] ~~~~ ~~~~~~~ ~~~~~~~~ ~~~~~~~~ [ SYNCRONIZED|SYNCHRONISED [ LEFT|RIGHT ] ] ~~~~ ~~~~ ~~~~ ~~~~~ [ USAGE IS data-item-usage ] . [ LINKAGE-SECTION-Data-Item ]... ~~~~~ The "LEFT" and "RIGHT" (SYNCRONIZED) clauses are syntactically recognized but are otherwise non-functional. ———————————————————————————————————————— The linkage section describes data within a subprogram that serves as either input argu- ments to or output results from the subprogram. 1. The reserved words "BY", "CHARACTER", "IS", "KEY", "ON" and "WHEN" are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program. 2. The reserved words "SYNCRONIZED" and ""SYNCRONISED"" are interchangeable. Both may be abbreviated as "SYNC". Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 105 3. The reserved word "PICTURE" may be abbreviated to "PIC". 4. The reserved word "JUSTIFIED" may be abbreviated to "JUST". 5. As the syntax diagram shows, the definition of a <> is a recursive one in that there may be any number of such specifications coded following one another. The first such specification must have a level number of 01. Specifications that follow that one may have level numbers greater than 01, in which case they are defining a hierarchical breakdown of a record. The definition of a record is terminated when one of the following occurs: • Another 01-level item is found — this signifies the end of the definition of one record and the start of a another. • A division or section header is found — this also marks the completion of a record and signifies the end of the linkage section as well. 6. Every <> description must be terminated with a period. 7. The only valid level numbers are 01-49, 66, 77, 78 and 88. Level numbers 01 through 49 are used to define data items that may be part of a hierarchical structure. Level number 01 can also be used to define a constant — an item with an unchangable value specified at compilation time. 8. Level numbers 66, 77, 78 and 88 all have special uses — See [Special Data Items], page 118, for details. 9. It is expected that: A. A linkage section should occur only within a subprogram. The compiler will not prevent its use in a main program, however. B. All 01-level data items described within a subprogram’s linkage section should ap- pear in a "PROCEDURE DIVISION USING" (see [PROCEDURE DIVISION USING], page 202) or as arguments on an "ENTRY" statement. C. Each 01-level data item described within a subprogram’s linkage section should correspond to an argument passed on a "CALL" statement (see [CALL], page 359) or an argument on a function call to the subprogram. 10. Not specifying an or "FILLER" immediately after the level number has the same effect as if "FILLER" were specified. A data item named "FILLER" cannot be referenced directly; these items are generally used to specify an unused portion of the total storage allocated to a group item or to describe a group item whose contents which will only be referenced using the names of those items that belong to it. In the linkage section, 01-level data items cannot be named "FILLER". 11. No storage is allocated for data defined in the linkage section; the data descriptions there are merely defining storage areas that will be passed to the subprogram by a calling program. Therefore, any discussion of the default initialization of such data is irrelevant. It is possible, however, to manually allocate linkage section data items 3 June 2014 Chapter 5 - DATA DIVISION 106 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide that aren’t subprogram arguments via the "ALLOCATE" statement (see [ALLOCATE], page 356) statement. In such cases, initialization will take place as per the documen- tation of that statement. 12. See [Data Description Clauses], page 125, for information on the usage of the various data description clauses. Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 107 5.6. REPORT SECTION (cid:11) (cid:10) REPORT SECTION Syntax (cid:8) (cid:9) [ REPORT SECTION. ~~~~~~ ~~~~~~~ { Report-Description [ { Report-Group-Definition } ]... { { { 01-Level-Constant { 78-Level-Constant { 01-Level-Constant { 78-Level-Constant } } }... ] } } } } ———————————————————————————————————————— (cid:11) (cid:8) (cid:10) Report-Description (RD) Syntax (cid:9) RD report-name [ IS GLOBAL ] ~~ [ CODE IS literal-1 | identifier-1 ] ~~~~~~ ~~~~ }... [ { CONTROL IS { ~~~~~~~ } { CONTROLS ARE } { identifier-2 } } { FINAL } { ~~~~~ ] ~~~~~~~~ [ PAGE [ { LIMIT IS } ] [ { literal-2 { ~~~~~ } { LIMITS ARE } ~~~~ { identifier-3 } ~~~~ } LINES ] ~~~~~~ [ literal-3 | identifier-4 COLUMNS|COLS ] ~~~~~~~ ~~~~ [ HEADING IS literal-4 | identifier-5 ] ~~~~~~~ [ FIRST DE|DETAIL IS literal-5 | identifier-6 ] ~~~~~ ~~ ~~~~~~ [ LAST CH|{CONTROL HEADING} IS literal-6 | identifier-7 ] ~~~~ ~~ ~~~~~~~ ~~~~~~~ [ LAST DE|DETAIL IS literal-7 | identifier-8 ] ~~~~ ~~ ~~~~~~ [ FOOTING IS literal-8 | identifier-9 ] ] . ~~~~~~~ The "CODE IS" and "COLUMNS" clauses are syntactically recognized but are otherwise non- functional. ———————————————————————————————————————— 3 June 2014 Chapter 5 - DATA DIVISION 108 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide This section describes the layout of printed reports as well as many of the functional aspects of the generation of reports that will be produced via the Report Writer Control System. 1. The reserved words "ARE" and "IS" are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program. 2. The phrases "CONTROL IS" and "CONTROLS ARE" are interchangeable, as are the "PAGE LIMIT" and "PAGE LIMITS" phrases. 3. The reserved word "LINES" may be abbreviated as "LINE". 4. The reserved word "COLUMNS" may be abbreviated as "COLS". 5. Each report referenced on a "REPORT IS" clause (see [File/Sort-Description], page 94) must be described with a report description ("RD"). 6. See [GLOBAL], page 146, for information on the "GLOBAL" option. 7. Please see [Report Writer Features], page 22, if you have not read it already. This will familiarize you with the Report Writer terminology that will follow. 8. The following rules pertain to the "PAGE LIMITS" clause: A. If no "PAGE LIMITS" clause is specified, the entire report will be generated as if it consists of a single arbitrarily long page. B. All literals ( through ) must be numeric with non-zero positive integer values. C. All identifiers ( through ) must be numeric, unedited with non-zero positive integer values. D. Any value specified for | will define the total number of available lines on any report page, not counting any unused margins at the top and/or bottom of the page (defined by the "LINES AT TOP" and "LINES AT BOTTOM" values specified on the "LINAGE" clause of the "FD" this "RD" is linked to — see [File/Sort-Description], page 94). E. Any value specified for | will be ignored. F. The "HEADING" clause defines the first line number at which a report heading or page heading may be presented. G. The "FIRST DETAIL" clause defines the first line at which a detail group may be presented. H. The "LAST CONTROL" HEADING clause defines the last line at which any line of a control heading may be presented. I. The "LAST DETAIL" clause defines the last line at which any line of a detail group may be presented. J. The "FOOTING" clause defines the last line at which any line of a control footing Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 109 group may be presented. K. The following rules establish default values for the various "PAGE LIMIT" clauses, assuming there is one: • "HEADING" — the default is one (1) • "FIRST DETAIL" — the HEADING value is used • "LAST CONTROL HEADING" — the value from "LAST DETAIL" or, if that is absent, the value from "FOOTING" or, if that too is absent, the value from "PAGE LIMIT" • "LAST DETAIL" — the value from "FOOTING" or, if that is absent, the value from "PAGE LIMIT" • "FOOTING" — the value from "LAST DETAIL" or, if that is absent, the value from "PAGE LIMIT" L. For the values specified on a "PAGE LIMIT" clause to be valid, all of the following must be true: • "HEADING" not > "FIRST DETAIL" • "FIRST DETAIL" not > "LAST CONTROL HEADING" • "LAST CONTROL HEADING" not > "LAST DETAIL" • "LAST DETAIL" not > "FOOTING" 9. The following rules pertain to the "CONTROL" clause: A. If there is no "CONTROL" clause, the report will contain no control breaks; this implies that there can be no "CONTROL HEADING" or "CONTROL FOOTING" report groups defined for this "RD". B. Include the reserved word "FINAL" if you want to include a special control heading before the first detail line is generated ("CONTROL HEADING FINAL") or after the last detail line is generated ("CONTROL FOOTING FINAL"). C. If you specify "FINAL", it must be the first control break named in the "RD". D. Any specifications included on the "CONTROL" clause are referencing data names defined in any data division section except for the report section. E. There must be a "CONTROL HEADING" and/or "CONTROL FOOTING" report group defined in the report section for each . F. At execution time: • Each time a "GENERATE" statement (see [GENERATE], page 391) is executed against a detail report group defined for this "RD", the RWCS will check the contents of each data item; whenever an ’s value has changed since the previous GENERATE, a control break condition will be in effect for that . 3 June 2014 Chapter 5 - DATA DIVISION 110 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide • Once the list of control breaks has been determined, the "CONTROL FOOTING" for each having a control break (if any such report group is defined) will be presented. • Next, the "CONTROL HEADING" for each having a control break (if any such report group is defined) will be presented. • The "CONTROL FOOTING" and "CONTROL HEADING" report groups will be pre- sented in the sequence in which they are listed on the "CONTROL" clause. • Only after this processing has occurred will the detail report group specified on the "GENERATE" be presented. 10. Each "RD" will have the following allocated for it: A. The "PAGE-COUNTER" special register (see [Special Registers], page 243), which will contain the current report page number. • This register will be set to a value of 1 when an "INITIATE" statement (see [INITIATE], page 404) is executed for the report and will be incremented by 1 each time the RWCS starts a new page of the report. • References to "PAGE-COUNTER" within the report section will be implicitly qualified with the name of the report to which the report group referencing the register belongs. • References to "PAGE-COUNTER" in the procedure division must be qualified with the appropriate report name if there are multiple "RD"s defined. B. The "LINE-COUNTER" special register, which will contain the current line number on the current page. 11. The "RD" must be followed by at least one 01-level report group definition. Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 111 5.6.1. Report Group Definitions (cid:11) (cid:10) 01 [ identifier-1 ] Report-Group-Definition Syntax [ LINE NUMBER IS { integer-1 [ [ ON NEXT PAGE ] } ] ~~~~ { { +|PLUS integer-1 { { ON NEXT PAGE ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ } } } } (cid:8) (cid:9) [ NEXT GROUP IS { [ +|PLUS ] integer-2 ~~~~ ~~~~~ } ] { } { NEXT|{NEXT PAGE}|PAGE } ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ [ TYPE IS { RH|{REPORT HEADING} ~~~~ } ] } { ~~ ~~~~~~ ~~~~~~~ } { PH|{PAGE HEADING} { ~~ ~~~~ ~~~~~~~ } { CH|{CONTROL HEADING} FINAL|identifier-2 } } { ~~ ~~~~~~~ ~~~~~~~ } { DE|DETAIL { ~~ ~~~~~~ } { CF|{CONTROL FOOTING} FINAL|identifier-2 } } { ~~ ~~~~~~~ ~~~~~~~ } { PF|{PAGE FOOTING} } { ~~ ~~~~ ~~~~~~~ } { RF|{REPORT FOOTING} ~~ ~~~~~~ ~~~~~~~ ~~~~~ ~~~~~ . [ REPORT-SECTION-Data-Item ]... ———————————————————————————————————————— The syntax shown here documents how a report group is defined to a report. This syntax is valid only in the report section, and only then after an "RD". 1. The reserved words "IS", "NUMBER" and "ON" are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program. 2. The "RH" and "REPORT HEADING" terms are interchangeable, as are "PH" and "PAGE HEADING", "CH" and "CONTROL HEADING", "DE" and "DETAIL", "CF" and "CONTROL FOOTING", "PF" and "PAGE FOOTING" as well as "RF" and "REPORT FOOTING". 3. The report group being defined will be a part of the most-recently coded "RD". 3 June 2014 Chapter 5 - DATA DIVISION 112 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 4. The "TYPE" (see [TYPE], page 184) clause specifies the type of report group being defined. 5. The level number used for a report group definition must be 01. 6. The optional specification assigns a name to this report group so that the group may be referenced either by a GENERATE statement or on a "USE BEFORE REPORTING". 7. No two report groups in the same report ("RD") may named with the same . There may, however, be multiple definitions in different reports. In such instances, references to must be qualified by the report name. 8. There may only be one report heading, report footing, final control heading, final control footing, page heading and page footing defined per report. 9. Report group declarations must be followed by at least one <> with a level number in the range 02-49. 10. See [Data Description Clauses], page 125, for information on the usage of the various data description clauses. Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 113 5.6.2. REPORT SECTION Data Items (cid:11) (cid:10) REPORT-SECTION-Data-Item Syntax (cid:8) (cid:9) level-number [ identifier-1 ] [ BLANK WHEN ZERO ] ~~~~~ ~~~~ [ COLUMN [ { NUMBER IS } ] [ +|PLUS ] integer-1 ] { ~~~~~~ } { NUMBERS ARE } ~~~~ ~~~ ~~~~~~~ [ GROUP INDICATE ] ~~~~~ ~~~~~~~~ [ JUSTIFIED RIGHT ] ~~~~ [ LINE NUMBER IS { integer-2 [ [ ON NEXT PAGE ] } ] ~~~~ ~~~~ { +|PLUS integer-2 ~~~~ ~~~~ { { ON NEXT PAGE ~~~~ ~~~~ } } } [ OCCURS [ integer-3 TO ] integer-4 TIMES ~~~~~~ ~~ [ DEPENDING ON identifier-2 ] ~~~~~~~~~ [ STEP integer-5 ] ~~~~ [ VARYING identifier-3 FROM { identifier-4 } BY { identifier-5 } ] ~~~~~~~ ~~~~ { integer-6 } ~~ { integer-7 } [ PICTURE IS picture-string ] ~~~ [ PRESENT WHEN condition-name ] ~~~~~~~ ~~~~ [ SIGN IS LEADING|TRAILING [ SEPARATE CHARACTER ] ] ~~~~ ~~~~~~~ ~~~~~~~~ ~~~~~~~~ [ { SOURCE IS literal-1|identifier-6 [ ROUNDED ] } ] { ~~~~~~ } { SUM OF { identifier-7 }... [ { RESET ON FINAL|identifier-8 } ] } } { literal-2 { ~~~ { VALUE IS [ ALL ] literal-3 } ~~~ { ~~~~~ { UPON identifier-9 ~~~~~~~ ~~~~~ ~~~~~ ~~~~ } } } . [ REPORT-SECTION-Data-Item ]... ———————————————————————————————————————— 3 June 2014 Chapter 5 - DATA DIVISION 114 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide Data item descriptions describing the report lines and fields that make up the substance of a report group immediately follow the definition of that group. 1. The reserved words "IS", "NUMBER", "OF", "ON", "RIGHT", "TIMES" and "WHEN" (BLANK) are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program. 2. The reserved word "COLUMN" may be abbreviated as "COL". 3. The reserved word "JUSTIFIED" may be abbreviated as "JUST". 4. The reserved word "PICTURE" may be abbreviated as "PIC". 5. The "SOURCE" (see [SOURCE], page 178), "SUM" (see [SUM], page 326) and "VALUE" (see [VALUE], page 197) clauses, valid only on an elementary item, are mutually- exclusive of each other. 6. Group items (those without "PICTURE" clauses) are frequently used to describe entire lines of a report, while elementary items (those with a picture clause) are frequently used to describe specific fields of information on the report. When this coding conven- tion is being used, group items will have "LINE" (see [LINE], page 153) clauses and no "COLUMN" (see [COLUMN], page 136) clauses while elementary items will be specified the other way around. 7. See [Data Description Clauses], page 125, for information on the usage of the various data description clauses. Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 115 5.7. SCREEN SECTION (cid:11) (cid:10) SCREEN-SECTION-Data-Item Syntax (cid:8) (cid:9) level-number [ identifier-1 | FILLER ] ~~~~~~ [ AUTO | AUTO-SKIP | AUTOTERMINATE ] [ BELL | BEEP ] ~~~~ ~~~~~~~~~ ~~~~~~~~~~~~~ ~~~~ ~~~~ [ BACKGROUND-COLOR|BACKGROUND-COLOUR IS integer-1 | identifier-2 ] ~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~ [ BLANK LINE|SCREEN ] [ ERASE EOL|EOS ] ~~~~~ ~~~~ ~~~~~~ ~~~~~ ~~~ ~~~ [ BLANK WHEN ZERO ] [ JUSTIFIED RIGHT ] ~~~~~ ~~~~ ~~~~ [ BLINK ] [ HIGHLIGHT | LOWLIGHT ] [ REVERSE-VIDEO ] ~~~~~ ~~~~~~~~ [ COLUMN NUMBER IS [ +|PLUS ] integer-2 | identifier-3 ] ~~~~~~~~~~~~~ ~~~~~~~~~ ~~~ ~~~~ [ FOREGROUND-COLOR|FOREGROUND-COLOUR IS integer-3 | identifier-4 ] ~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~ [ { FROM literal-1 | identifier-5 } ] { ~~~~ { TO identifier-5 { ~~ { USING identifier-5 { ~~~~~ { VALUE IS [ ALL ] literal-1 ~~~ ~~~~~ } } } } } } [ FULL | LENGTH-CHECK ] [ REQUIRED | EMPTY-CHECK ] [ SECURE | NO-ECHO ] ~~~~ ~~~~~~~~~~~~ ~~~~~~~~ ~~~~~~~~~~~ ~~~~~~ ~~~~~~~ [ LEFTLINE ] [ OVERLINE ] [ UNDERLINE ] ~~~~~~~~ ~~~~~~~~~ ~~~~~~~~ [ LINE NUMBER IS [ +|PLUS ] integer-4 | identifier-6 ] ~~~~ ~~~~ [ OCCURS integer-5 TIMES ] ~~~~~~ [ PICTURE IS picture-string ] ~~~ [ PROMPT [ CHARACTER IS literal-2 | identifier-7 ] ~~~~~~ ~~~~~~~~~ [ SIGN IS LEADING|TRAILING [ SEPARATE CHARACTER ] ] ~~~~ ~~~~~~~ ~~~~~~~~ [ SCREEN-SECTION-Data-Item ]... ~~~~~~~~ . ———————————————————————————————————————— 3 June 2014 Chapter 5 - DATA DIVISION 116 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide The screen section describes the screens to be displayed during terminal/console I-O. 1. The reserved words "CHARACTER" ("SEPARATE" clause), "IS", "NUMBER", "RIGHT", "TIMES" and "WHEN" are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the pro- gram. 2. The reserved word "COLUMN" may be abbreviated as "COL". 3. The reserved word "PICTURE" may be abbreviated as "PIC". 4. The following sets of reserved words are interchangeable: • "AUTO", "AUTO-SKIP" and "AUTOTERMINATE" • "BACKGROUND-COLOR" and "BACKGROUND-COLOUR" • "BELL" and "BEEP" • "FOREGROUND-COLOR" and "FOREGROUND-COLOUR" • "FULL" and "LENGTH-CHECK" • "REQUIRED" and "EMPTY-CHECK" • "SECURE" and "NO-ECHO" 5. Data items defined in the screen section describe input, output or combination screen layouts to be used with "ACCEPT screen-data-item" statement (see [ACCEPT screen- data-item], page 342) or "DISPLAY screen-data-item" statement (see [DISPLAY screen-data-item], page 374) statements. These screen layouts may define the entire available screen area or any subset of it. 6. The term ’available screen area’ is a nebulous one in those environments where command-line shell sessions are invoked within a graphical user-interface environment, as will be the case on Windows, OSX and most Unix/Linux systems — these environments allow command-line session windows to exist with a variable number of available screen rows and columns. When you are designing GNU COBOL screens, you need to do so with an awareness of the logical screen row/column geometry the program will be executing within. 7. Data items with level numbers 01 (Constants), 66, 78 and 88 may be used in the screen section; they have the same syntax, rules and usage as they do in the other data division sections. 8. Without "LINE" (see [LINE], page 153) or "COLUMN" (see [COLUMN], page 136) clauses, screen section fields will display on the console window beginning at what- ever line/column coordinate is stated or implied by the "ACCEPT screen-data-item" or "DISPLAY screen-data-item" statement that presents the screen item. After a field is presented to the console window, the next field will be presented immediately following that field. 9. A "LINE" clause explicitly stated in the definition of a screen section data item will override any "LINE" clause included on the "ACCEPT screen-data-item" or "DISPLAY Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 117 screen-data-item" statement that presents that data item to the screen. The same is true of "COLUMN" clauses. 10. The Tab and Back-Tab (Shift-Tab on most keyboards) keys will position the cursor from field to field in the line/column sequence in which the fields occur on the screen at execution time, regardless of the sequence in which they were defined in the screen section. 11. See [Data Description Clauses], page 125, for information on the usage of the various data description clauses. 3 June 2014 Chapter 5 - DATA DIVISION 118 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 5.8. Special Data Items 5.8.1. 01-Level Constants (cid:11) (cid:10) 01-Level-Constant Syntax 01 constant-name-1 CONSTANT [ IS GLOBAL ] ~~~~~~~~ ~~~~~~ (cid:8) (cid:9) { AS { literal-1 { { { { { FROM CDF-variable-name-1 { { BYTE-LENGTH } OF { identifier-1 } } } } } } { { ~~~~~~~~~~~ } } } { { LENGTH } } ~~~~~~ } { usage-name } } . ~~~~ ———————————————————————————————————————— This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE, LINKAGE, SCREEN The 01-level constant is one of four types of compilation-time constants that can be declared within a program. The other three types are ">>DEFINE" CDF directive (see [>>DEFINE], page 45) constants, ">>SET" CDF directive (see [>>SET], page 49) constants and 78-level constants (see [78-Level Data Items], page 123). 1. The reserved words "AS", "IS" and "OF" are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program. 2. See [GLOBAL], page 146, for information on the "GLOBAL" option. 3. This particular type of constant declaration provides the ability to determine the length of a data item or the storage size associated with a particular numeric "USAGE" (see [USAGE], page 186) type — something not possible with the other types of constants. 4. Constants defined in this way become undefined once an "END PROGRAM" or "END FUNCTION" is encountered in the input source. 5. Data descriptions of this form do not actually allocate any storage — they merely define a name () that may be used anywhere a numeric literal ("BYTE-LENGTH" or "LENGTH" options) or a literal of the same type as may be used. 6. The name may not be referenced on a CDF directive. 7. Care must be taken that does not duplicate any other data item name that has been defined in the program as references to that data item name will refer to the constant and not the data item. The GNU COBOL compiler will not issue a warning about this condition. Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 119 8. The value specified for may be any "USAGE" that does not These would be any use a "PICTURE" (see [PICTURE], page 162) clause. "BINARY-LONG", of "BINARY-SHORT", (or "COMP-2" "COMPUTATIONAL-2"), "FLOAT-DECIMAL-16", "FLOAT-DECIMAL-34", "FLOAT-LONG", "FLOAT-SHORT", "POINTER", or "PROGRAM-POINTER". "COMPUTATIONAL-1"), "BINARY-DOUBLE", "BINARY-C-LONG", "BINARY-CHAR", "COMP-1" (or 9. The "BYTE-LENGTH" clause will produce a numeric value for identi- cal to that which would be returned by the "BYTE-LENGTH" intrinsic function executed against or a data item declared with a "USAGE" of . 10. The "LENGTH" clause will produce a numeric value for identical to that which would be returned by the "LENGTH" intrinsic function executed against or a data item declared with a "USAGE" of . Here is the listing of a GNU COBOL program that uses 01-level constants to display the length (in bytes) of the various picture-less usage types. CONSTANT AS LENGTH OF BINARY-C-LONG. CONSTANT AS LENGTH OF BINARY-CHAR. CONSTANT AS LENGTH OF BINARY-DOUBLE. CONSTANT AS LENGTH OF BINARY-LONG. CONSTANT AS LENGTH OF BINARY-SHORT. CONSTANT AS LENGTH OF COMP-1. CONSTANT AS LENGTH OF COMP-2. IDENTIFICATION DIVISION. PROGRAM-ID. USAGELengths. DATA DIVISION. WORKING-STORAGE SECTION. 01 Len-BINARY-C-LONG 01 Len-BINARY-CHAR 01 Len-BINARY-DOUBLE 01 Len-BINARY-LONG 01 Len-BINARY-SHORT 01 Len-COMP-1 01 Len-COMP-2 01 Len-FLOAT-DECIMAL-16 CONSTANT AS LENGTH OF FLOAT-DECIMAL-16. 01 Len-FLOAT-DECIMAL-34 CONSTANT AS LENGTH OF FLOAT-DECIMAL-34. 01 Len-FLOAT-LONG 01 Len-FLOAT-SHORT 01 Len-POINTER 01 Len-PROGRAM-POINTER CONSTANT AS LENGTH OF PROGRAM-POINTER. PROCEDURE DIVISION. 000-Main. CONSTANT AS LENGTH OF FLOAT-LONG. CONSTANT AS LENGTH OF FLOAT-SHORT. CONSTANT AS LENGTH OF POINTER. DISPLAY "On this system, with this build of GNU COBOL, the" DISPLAY "PICTURE-less USAGEs have these lengths (in bytes):" DISPLAY " " DISPLAY "BINARY-C-LONG: DISPLAY "BINARY-CHAR: DISPLAY "BINARY-DOUBLE: DISPLAY "BINARY-LONG: DISPLAY "BINARY-SHORT: DISPLAY "COMP-1: DISPLAY "COMP-2: " Len-BINARY-C-LONG " Len-BINARY-CHAR " Len-BINARY-DOUBLE " Len-BINARY-LONG " Len-BINARY-SHORT " Len-COMP-1 " Len-COMP-2 3 June 2014 Chapter 5 - DATA DIVISION 120 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide DISPLAY "FLOAT-DECIMAL-16: " Len-FLOAT-DECIMAL-16 DISPLAY "FLOAT-DECIMAL-34: " Len-FLOAT-DECIMAL-34 DISPLAY "FLOAT-LONG: DISPLAY "FLOAT-SHORT: DISPLAY "POINTER: DISPLAY "PROGRAM-POINTER: " Len-PROGRAM-POINTER STOP RUN . " Len-FLOAT-LONG " Len-FLOAT-SHORT " Len-POINTER The output of this program, on a Windows 7 system with a 32-bit MinGW build of GNU COBOL is: On this system, with this build of GNU COBOL, the PICTURE-less USAGEs have these lengths (in bytes): 4 BINARY-C-LONG: 1 BINARY-CHAR: 8 BINARY-DOUBLE: 4 BINARY-LONG: 2 BINARY-SHORT: 4 COMP-1: 8 COMP-2: FLOAT-DECIMAL-16: 8 FLOAT-DECIMAL-34: 16 8 FLOAT-LONG: 4 FLOAT-SHORT: POINTER: 4 PROGRAM-POINTER: 4 Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 121 5.8.2. 66-Level Data Items (cid:11) (cid:10) 66-Level-Data-Item Syntax (cid:8) (cid:9) 66 identifier-1 RENAMES identifier-2 [ THRU|THROUGH identifier-3 ] . ~~~~~~~ ~~~~ ~~~~~~~ ———————————————————————————————————————— This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE, LINKAGE A 66-level data item regroups previously defined items by specifying alternative, possibly overlapping, groupings of elementary data items. 1. The reserved words "THRU" and "THROUGH" are interchangeable. 2. A level-66 data item cannot rename a level-66, level-01, level-77, or level-88 data item. 3. There may be multiple level-66 data items that rename data items contained within the same 01-level record description. 4. All "RENAMES" entries associated with one logical record must immediately follow that record’s last data description entry. 3 June 2014 Chapter 5 - DATA DIVISION 122 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide (cid:8) (cid:9) 5.8.3. 77-Level Data Items (cid:11) (cid:10) 77-Level-Data-Item Syntax 77 identifier-1 [ IS GLOBAL|EXTERNAL ] ~~~~~~ ~~~~~~~~ [ BASED ] ~~~~~ [ BLANK WHEN ZERO ] ~~~~~ ~~~~ [ JUSTIFIED RIGHT ] ~~~~ [ PICTURE IS picture-string ] ~~~ [ REDEFINES identifier-5 ] ~~~~~~~~~ [ SIGN IS LEADING|TRAILING [ SEPARATE CHARACTER ] ] ~~~~ ~~~~~~~ ~~~~~~~~ ~~~~~~~~ [ SYNCRONIZED|SYNCHRONISED [ LEFT|RIGHT ] ] ~~~~ ~~~~ ~~~~ ~~~~~ [ USAGE IS data-item-usage ] ~~~~~ [ VALUE IS [ ALL ] literal-1 ] . ~~~~~ ~~~ The "LEFT" and "RIGHT" (SYNCRONIZED) clauses are syntactically recognized but are otherwise non-functional. ———————————————————————————————————————— This syntax is valid in the following sections: WORKING-STORAGE, LOCAL-STORAGE, LINKAGE The intent of a 77-level item is to be able to create a stand-alone elementary data item. 1. The reserved words "CHARACTER", "IS", "RIGHT" (JUSTIFIED) and "WHEN" are op- tional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program. 2. The reserved word "JUSTIFIED" may be abbreviated as "JUST", the reserved word "PICTURE" may be abbreviated as "PIC" and the reserved words "SYNCRONIZED" and "SYNCRONISED" may be abbreviated as "SYNC". 3. New programs requiring a stand-alone elementary item should be coded to use a level number of 01 rather than 77. 4. See [Data Description Clauses], page 125, for information on the usage of the various data description clauses. Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 123 5.8.4. 78-Level Data Items (cid:11) (cid:10) 78-Level-Constant Syntax 78 constant-name-1 VALUE IS literal-1 . ~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE, LINKAGE, SCREEN The 78-level constant is one of four types of compilation-time constants that can be declared within a program. The other three types are ">>DEFINE" CDF directive (see [>>DEFINE], page 45) constants, ">>SET" CDF directive (see [>>SET], page 49) constants and 01-level constants (see [01-Level Constants], page 118). 1. The reserved word "IS" is optional and may be included, or not, at the discretion of the programmer. The presence or absence of this word has no effect upon the program. 2. Constants defined in this way become undefined once an "END PROGRAM" or "END FUNCTION" is encountered in the input source. 3. Data descriptions of this form do not actually allocate any storage — they merely define a name () that may be used anywhere a literal of the same type as may be used. 4. The name may not be referenced on a CDF directive. 5. Care must be taken that does not duplicate any other data item name that has been defined in the program as references to that data item name will refer to the constant and not the data item. The GNU COBOL compiler will not issue a warning about this condition. 3 June 2014 Chapter 5 - DATA DIVISION 124 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 5.8.5. 88-Level Data Items (cid:11) (cid:10) 88-Level-Data-Item Syntax (cid:8) (cid:9) 88 condition-name-1 { VALUE IS } {literal-1 [ THRU|THROUGH literal-2 ]}... ~~~~ ~~~~~~~ } { ~~~~~ { VALUES ARE } ~~~~~~ [ WHEN SET TO FALSE IS literal-3 ] . ~~~~~ ———————————————————————————————————————— This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE, LINKAGE, REPORT, SCREEN Condition names are Boolean (i.e. TRUE / FALSE) data items that receive their TRUE and FALSE values based upon the values of the non 88-level data item whose definition they immediately follow. 1. The reserved words "ARE", "IS", "SET" and "TO" are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program. 2. The reserved words "THRU" and "THROUGH" are interchangeable. 3. Condition names are always defined subordinate to another (non 88-level) data item. That data item must be an elementary item. Whenever the parent data item assumes one of the values specified on the 88-level item’s "VALUE" (see [VALUE], page 197) clause, will take on the value of TRUE. 4. Condition names do not occupy any storage. 5. The optional "THROUGH" clause allows a range of possible TRUE values to be specified. 6. Whenever the parent data item assumes any value except one of the values specified on ’s "VALUE" clause, will take on the value of FALSE. 7. Executing the statement "SET TO TRUE" will cause ’s parent data item to take on the first value specified on ’s "VALUE" clause. 8. Executing the statement "SET TO FALSE" will cause ’s parent data item to take on the value specified on ’s "FALSE" clause. If does not have a "FALSE" clause, the "SET" (see [SET], page 445) statement will generate an error message at compilation time. 9. See [Condition Names], page 218, for more information. Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 125 5.9. Data Description Clauses 5.9.1. ANY LENGTH (cid:11) (cid:10) ANY LENGTH ~~~ ~~~~~~ ANY LENGTH Attribute Syntax (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: LINKAGE Data items declared with the "ANY LENGTH" attribute have no fixed compile-time length. Such items may only be defined in the linkage section of a subprogram as they may only serve as subroutine argument descriptions. These items must have a "PICTURE" (see [PICTURE], page 162) clause that specifies exactly one A, X or 9 symbol. 1. The "ANY LENGTH" and "BASED" (see [BASED], page 130) clauses cannot be used to- gether in the same data item description. 3 June 2014 Chapter 5 - DATA DIVISION 126 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 5.9.2. AUTO (cid:11) (cid:10) AUTO ~~~~ AUTO Attribute Syntax (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: SCREEN A field whose description includes this attribute will cause the cursor to automatically advance to the next input-enabled field of a screen if the field is completely filled with input data. 1. The "AUTO", "AUTO-SKIP" (see [AUTO-SKIP], page 127) and "AUTOTERMINATE" (see [AUTOTERMINATE], page 128) clauses are interchangeable, and may not be used together in the same data item description. Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 127 5.9.3. AUTO-SKIP (cid:11) (cid:10) AUTO-SKIP ~~~~~~~~~ AUTO-SKIP Attribute Syntax (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: SCREEN A field whose description includes this attribute will cause the cursor to automatically advance to the next input-enabled field of a screen if the field is completely filled with input data. 1. The "AUTO" (see [AUTO], page 126), "AUTO-SKIP" and "AUTOTERMINATE" (see [AUTOTERMINATE], page 128) clauses are interchangeable, and may not be used together in the same data item description. 3 June 2014 Chapter 5 - DATA DIVISION 128 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 5.9.4. AUTOTERMINATE (cid:11) AUTOTERMINATE Attribute Syntax (cid:10) AUTOTERMINATE ~~~~~~~~~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: SCREEN A field whose description includes this attribute will cause the cursor to automatically advance to the next input-enabled field of a screen if the field is completely filled with input data. 1. The "AUTO" (see [AUTO], page 126), "AUTO-SKIP" (see [AUTO-SKIP], page 127) and "AUTOTERMINATE" clauses are interchangeable, and may not be used together in the same data item description. Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 129 5.9.5. BACKGROUND-COLOR (cid:11) (cid:10) BACKGROUND-COLOR Attribute Syntax BACKGROUND-COLOR|BACKGROUND-COLOUR IS integer-1 | identifier-1 ~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: SCREEN This clause is used to specify the screen background color of the screen data item or the default screen background color of subordinate items if used on a group item. 1. The reserved word "IS" is optional and may be included, or not, at the discretion of the programmer. The presence or absence of this word has no effect upon the program. 2. The reserved words "BACKGROUND-COLOR" and "BACKGROUND-COLOUR" are interchange- able. 3. You specify colors by number (0-7), or by using the constant names provided in the "screenio.cpy" copybook (which is provided with all GNU COBOL source distribu- tions). 4. Colors may also be specified using a numeric non-edited identifier whose value is in the range 0-7. See [Color Palette and Video Attributes], page 20, for more information on screen colors and video attributes. 3 June 2014 Chapter 5 - DATA DIVISION 130 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 5.9.6. BASED (cid:11) (cid:10) BASED ~~~~~ BASED Attribute Syntax (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: WORKING-STORAGE, LOCAL-STORAGE, LINKAGE Data items declared with "BASED" are allocated no storage at compilation time. At run- time, the "ALLOCATE" (see [ALLOCATE], page 356) or "SET ADDRESS" (see [SET AD- DRESS], page 447) statements are used to allocate space for and (optionally) initialize such items. 1. The "BASED" and "ANY LENGTH" (see [ANY LENGTH], page 125) clauses cannot be used together in the same data item description. 2. The "BASED" clause may only be used on level 01 and level 77 data items. Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 131 5.9.7. BEEP (cid:11) (cid:10) BEEP ~~~~ BEEP Attribute Syntax (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: SCREEN 1. The "BEEP" and "BELL" (see [BELL], page 132) clauses are interchangeable, and may not be used together in the same data item description. 2. Use this clause to cause an audible tone to occur when the screen item is DISPLAYed. 3 June 2014 Chapter 5 - DATA DIVISION 132 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 5.9.8. BELL (cid:11) (cid:10) BELL ~~~~ BELL Attribute Syntax (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: SCREEN 1. The "BEEP" (see [BEEP], page 131) and "BELL" clauses are interchangeable, and may not be used together in the same data item description. 2. Use this clause to cause an audible tone to occur when the screen item is DISPLAYed. Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 133 5.9.9. BLANK (cid:11) (cid:10) BLANK LINE|SCREEN ~~~~~ ~~~~ ~~~~~~ BLANK Attribute Syntax (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: SCREEN This clause will blank out either the entire screen (BLANK SCREEN) or just the line upon which data is about to be displayed (BLANK LINE). 1. Blanked-out areas will have their foreground and background colors set to the attributes of the field containing the "BLANK" clause. 2. This clause is useful when one screen section item is being displayed over the top of a previously-displayed one. 3 June 2014 Chapter 5 - DATA DIVISION 134 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 5.9.10. BLANK WHEN ZERO (cid:11) BLANK-WHEN-ZERO Attribute Syntax (cid:10) BLANK WHEN ZERO ~~~~ ~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE, LINKAGE, REPORT, SCREEN This clause will cause that item’s value to be automatically transformed into spaces if a value of 0 is ever MOVEd to the item. 1. The reserved word "WHEN" is optional and may be included, or not, at the discretion of the programmer. The presence or absence of this word has no effect upon the program. 2. This clause may only be used on a PIC 9 data item with a "USAGE" (see [USAGE], page 186) of "DISPLAY". Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 135 5.9.11. BLINK (cid:11) (cid:10) BLINK ~~~~~ BLINK Attribute Syntax (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: SCREEN The "BLINK" clause modifies the visual appearance of the displayed field by making the field contents blink. See [Color Palette and Video Attributes], page 20, for more information on screen colors and video attributes. 3 June 2014 Chapter 5 - DATA DIVISION 136 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 5.9.12. COLUMN (cid:11) (cid:10) COLUMN (REPORT SECTION) Clause Syntax } ] [ +|PLUS ] integer-1 ] (cid:8) (cid:9) COLUMN [ { NUMBER IS ~~~ { NUMBERS ARE } ~~~~ ———————————————————————————————————————— (cid:11) (cid:8) (cid:10) COLUMN (SCREEN SECTION) Clause Syntax (cid:9) COLUMN NUMBER IS [ +|PLUS ] integer-2 | identifier-3 ] ~~~ ~~~~ ———————————————————————————————————————— This syntax is valid in the following sections: REPORT, SCREEN The "COLUMN" clause provides the means of stating in which column a field should be presented on the console window (screen section) or a report (report section). 1. The reserved words "ARE", "IS", "NUMBER" and "NUMBERS" are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program. 2. The reserved word "COLUMN" may be abbreviated as "COL". 3. The line location of a report section or screen section field will be determined by the "LINE" (see [LINE], page 153) clause. 4. The value of must be 1 or greater. 5. If is used to specify either an absolute or relative column position, must be defined as a numeric item of any "USAGE" (see [USAGE], page 186) other than "COMPUTATIONAL-1" or "COMPUTATIONAL-2", without editing symbols. The value of at the time the screen data item is presented must be 1 or greater. Note that a "COMPUTATIONAL-1" or "COMPUTATIONAL-2" identifier will be accepted by the compiler, but will produce unpredictable results at run-time. 6. The column coordinate of a field may be stated on an absolute basis (i.e. "COLUMN 5") or on a relative basis based upon the end of the previously-presented field (i.e. "COLUMN PLUS 1"). 7. The symbol "+" may be used in lieue of the word "PLUS", if desired; if symbol "+" is used, however, there must be at least one space separating it from . Failure to include this space will cause the symbol "+" sign to be simply treated as part of and will treat the "COLUMN" clause as an absolute column specification rather than a relative one. Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 137 8. Using relative column positioning ("COLUMN PLUS") has slightly different behavior de- pending upon the section in which the clause is used, as follows: A. When used on a report section data item, "COLUMN PLUS" will position the start of the new field’s value such that there are blank columns between the end of the previous field and the beginning of this field. If a report data item’s description includes the "SOURCE" (see [SOURCE], page 178), "SUM" (see [SUM], page 326) or "VALUE" (see [VALUE], page 197) clause but has no "COLUMN" clause, "COLUMN PLUS 1" will be assumed. B. When used on a screen section data item, "COLUMN PLUS" will position the new field so that it begins exactly or characters past the last character of the previous field. Thus, "COLUMN PLUS 1" will leave no blank positions between the end of the previous field and the start of this one. If a screen data item’s description includes the "FROM" (see [FROM], page 144), "TO" (see [TO], page 183), "USING" (see [USING], page 196) or "VALUE" (see [VALUE], page 197) clause but has no "COLUMN" clause, the new screen field will begin at the column coordinate of the last character of the previous field. 3 June 2014 Chapter 5 - DATA DIVISION 138 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 5.9.13. CONSTANT (cid:11) (cid:10) CONSTANT ~~~~~~~~ CONSTANT Attribute Syntax (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE, LINKAGE, SCREEN This option signifies that the 01-level data item in whose declaration "CONSTANT" is specified will be treated as a symbolic name for a literal value, useable wherever a literal of the appropriate type could be used. 1. The value of a data item defined as a constant cannot be changed at run-time. In fact, it is not syntactically acceptable to use such a data item as the destination field of any procedure division statement that stores a value. 2. See [01-Level Constants], page 118, for additional information. Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 139 5.9.14. EMPTY-CHECK (cid:11) (cid:10) EMPTY-CHECK ~~~~~~~~~~~ EMPTY-CHECK Attribute Syntax (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: SCREEN This clause forces the user to enter data into the field it is specified on (or into all subordinate input-capable fields if "EMPTY-CHECK" is specified on a group item). 1. The "EMPTY-CHECK" and "REQUIRED" (see [REQUIRED], page 174) clauses are inter- changeable, and may not be used together in the same data item description. 2. In order to take effect, the user must first move the cursor into the field having this clause in its definition. 3. The "ACCEPT screen-data-item" statement [ACCEPT screen-data-item], page 342) will ignore the Enter key and any other cursor-moving keystrokes that would cause the cursor to move to another screen item unless data has been entered into the field. Function keys will still be allowed to terminate the "ACCEPT". (see 4. In order to be functional, this attribute must be supported by the underlying ’curses’ package your GNU COBOL implementation was built with. As of this time, the ’PDCurses’ package (used for native Windows or MinGW builds) does not support "EMPTY-CHECK". 3 June 2014 Chapter 5 - DATA DIVISION 140 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 5.9.15. ERASE (cid:11) (cid:10) ERASE EOL|EOS ~~~~~ ~~~ ~~~ ERASE Clause Syntax (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: SCREEN "ERASE" will blank-out screen contents from the location where the screen data item whose description contains this clause will be displayed, forward until the end of the screen ("ERASE EOS") or line ("ERASE EOL") prior to displaying the screen data item. 1. Erased areas will have their foreground and background colors set to the attributes of the field containing the "ERASE" clause. 2. This clause is useful when one screen section item is being displayed over the top of a previously-displayed one. See [Color Palette and Video Attributes], page 20, for more information on screen colors and video attributes. Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 141 5.9.16. EXTERNAL (cid:11) (cid:10) EXTERNAL ~~~~~~~~ EXTERNAL Attribute Syntax (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE This clause marks a data item description, "FD" or "SD" see [File/Sort-Description], page 94 as being sharable with other programs executed from the same execution thread. 1. By specifying the "EXTERNAL" clause on either an FD or an SD, the file description is capable of being shared between all programs executed from the same execution thread, provided an "EXTERNAL" clause is coded with the file’s description in each program requiring it. This sharing allows the file to be opened, read and/or written and closed in different programs. This sharing applies to the record descriptions subordinate to the file description too. 2. By specifying the "EXTERNAL" clause on the description of a data item, the data item is capable of being shared between all programs executed from the same execution thread, provided the data item is coded (with an "EXTERNAL" clause) in each program requiring it. 3. The following points apply to the specification of "EXTERNAL" in a data item’s definition: A. The "EXTERNAL" clause may only be specified at the 77 or 01 level. B. An "EXTERNAL" item must have a data name and that name cannot be "FILLER". C. "EXTERNAL" cannot be combined with "BASED" (see [BASED], page 130), "GLOBAL" (see [GLOBAL], page 146) or "REDEFINES" (see [REDEFINES], page 172). 3 June 2014 Chapter 5 - DATA DIVISION 142 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 5.9.17. FALSE (cid:11) (cid:10) FALSE Clause Syntax WHEN SET TO FALSE IS literal-1 ~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE, LINKAGE, REPORT, SCREEN This clause, which may only appear on the definition of a level-88 condition name, is used to specify the value of the data item that serves as the parent of the level-88 condition name that will force the condition name to assume a value of FALSE. 1. The reserved words "IS", "SET", "TO" and "WHEN" are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program. 2. See [88-Level Data Items], page 124, or See [Condition Names], page 218, for more information. Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 143 5.9.18. FOREGROUND-COLOR (cid:11) (cid:10) FOREGROUND-COLOR Attribute Syntax FOREGROUND-COLOR|FOREGROUND-COLOUR IS integer-1 | identifier-1 ~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: SCREEN This clause is used to specify the color of text within a screen data item or the default text color of subordinate items if used on a group item. 1. The reserved word "IS" is optional and may be included, or not, at the discretion of the programmer. The presence or absence of this word has no effect upon the program. 2. The reserved words "FOREGROUND-COLOR" and "FOREGROUND-COLOUR" are interchange- able. 3. You specify colors by number (0-7), or by using the constant names provided in the "screenio.cpy" copybook (which is provided with all GNU COBOL source distribu- tions). 4. Colors may also be specified using a numeric non-edited identifier whose value is in the range 0-7. See [Color Palette and Video Attributes], page 20, for more information on screen colors and video attributes. 3 June 2014 Chapter 5 - DATA DIVISION 144 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 5.9.19. FROM (cid:11) (cid:10) FROM literal-1 | identifier-5 ~~~~ FROM Clause Syntax (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: SCREEN This clause is used to specify either the data item a screen section field is to obtain it’s value from when the screen is displayed, or a literal that will specify the value of that same field. 1. The "FROM", "TO" (see [TO], page 183), "USING" (see [USING], page 196) and "VALUE" (see [VALUE], page 197) clauses are mutually-exclusive in any screen section data itsm’s definition. Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 145 5.9.20. FULL (cid:11) (cid:10) FULL ~~~~ FULL Attribute Syntax (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: SCREEN The "FULL" clause forces the user to enter data into the field it is specified on (or into all subordinate input-capable fields if specified on a group item) sufficient to fill every character position of the field. 1. The "FULL" and "LENGTH-CHECK" (see [LENGTH-CHECK], page 152) clauses are in- terchangeable, and may not be used together in the same data item description. 2. In order for this clause to take effect at execution time, the user must move the cursor into the field having this clause in its definition. 3. The "ACCEPT screen-data-item" statement [ACCEPT screen-data-item], page 342) will ignore the Enter key and any other cursor-moving keystrokes that would cause the cursor to move to another screen item unless the proper amount of data has been entered into the field. Function keys will still be allowed to terminate the "ACCEPT", however. (see 4. In order to be functional, this attribute must be supported by the underlying ’curses’ package your GNU COBOL implementation was built with. As of this time, the ’PD- Curses’ package (used for native Windows or MinGW builds) does not support "FULL". 3 June 2014 Chapter 5 - DATA DIVISION 146 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 5.9.21. GLOBAL (cid:11) (cid:10) GLOBAL ~~~~~~ GLOBAL Attribute Syntax (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE, REPORT This clause marks a data item, 01-level constant, "FD" (see [File/Sort-Description], page 94), "SD" (see [File/Sort-Description], page 94) or an "RD" (see [REPORT SECTION], page 107) as being sharable with any nested subprograms. 1. By specifying the "GLOBAL" clause on the description of a file or a report, that descrip- tion is capable of being shared between a program and any nested subprograms within it, provided the "FD", "SD" or "RD" is coded (with a "GLOBAL" clause) in each nested subprogram requiring it. This sharing allows the file to be opened, read and/or written and closed or the report to be initiated or terminated in those programs. Separately compiled programs may not share a "GLOBAL" file description, but they may share an "EXTERNAL" (see [EXTERNAL], page 141) file description. This sharing applies to the record descriptions subordinate to the file description and the report groups subordinate to the "RD" also. 2. By specifying the "GLOBAL" clause on the description of a data item, the data item is capable of being shared between a program and any nested subprograms within it, provided the data item is coded (with a "GLOBAL" clause) in each program requiring it. 3. The following points apply to the specification of "GLOBAL" in a data item’s definition: A. The "GLOBAL" clause may only be specified at the 77 or 01 level. B. A "GLOBAL" item must have a data name and that name cannot be "FILLER". C. "GLOBAL" cannot be combined with "EXTERNAL" (see [EXTERNAL], page 141), "REDEFINES" (see [REDEFINES], page 172) or "BASED" (see [BASED], page 130). Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 147 5.9.22. GROUP INDICATE (cid:11) GROUP-INDICATE Attribute Syntax (cid:10) GROUP INDICATE ~~~~~ ~~~~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: REPORT The "GROUP INDICATE" clause specifies that the data item in whose definition the clause appears will be presented only in very limited circumstances. 1. This clause may only appear within a "DETAIL" report group (see [TYPE], page 184). 2. When this clause is present, the data item in question will be presented only under the following circumstances: A. On the first presentation of the detail group following the "INITIATE" (see [INITIATE], page 404) of the report. B. On the first presentation of the detail group after every new page is started. C. On the first presentation of the detail group after any control break occurs. 3 June 2014 Chapter 5 - DATA DIVISION 148 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 5.9.23. HIGHLIGHT (cid:11) (cid:10) HIGHLIGHT ~~~~~~~~~ HIGHLIGHT Attribute Syntax (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: SCREEN This clause controls the intensity of text ("FOREGROUND-COLOR" (see [FOREGROUND- COLOR], page 143)) by setting that intensity to its highest of three possible settings. 1. This clause, along with "LOWLIGHT" (see [LOWLIGHT], page 155), are intended intensity scheme ("LOWLIGHT" . . . nothing (Normal) . . . to provide a three-level "HIGHLIGHT"). See [Color Palette and Video Attributes], page 20, for more information on screen colors and video attributes. Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 149 5.9.24. JUSTIFIED (cid:11) (cid:10) JUSTIFIED RIGHT ~~~~ JUSTIFIED Attribute Syntax (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE, LINKAGE, REPORT, SCREEN The presence of a "JUSTIFIED RIGHT" clause in a data item’s definition alters the manner in which data is stored into the field from the default ’left-justified, space filled’ behavior to ’right justified, space filled’. 1. The reserved word "RIGHT" is optional and may be included, or not, at the discretion of the programmer. The presence or absence of this word has no effect upon the program. 2. The reserved word "JUSTIFIED" may be abbreviated as "JUST". 3. This clause is valid only on alphabetic (PIC A) or alphanumeric (PIC X) data items. 4. The presence or absence of this clause influences the behavior of the "MOVE" (see [MOVE], page 414) statement as well as the "FROM" (see [FROM], page 144), "SOURCE" (see [SOURCE], page 178) and "USING" (see [USING], page 196) data item description clauses. 5. If the value being stored into the field is the same length as the receiving field, the presence or absence of the "JUSTIFIED RIGHT" clause on that field’s description is irrelevant. 6. The following examples illustrate the behavior of the presence and absence of the "JUSTIFIED RIGHT" clause when the field size is different than that of the value being stored. In these examples, the symbol b represents a space. When the value is shorter than the field size... Without JUSTIFIED With JUSTIFIED 01 A PIC X(6). MOVE "ABC" TO A 01 A PIC X(6) JUSTIFIED RIGHT. MOVE "ABC" TO A Result is ’ABCbbb’ Result is ’bbbABC’ 3 June 2014 Chapter 5 - DATA DIVISION 150 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide When the value is longer than the field size... Without JUSTIFIED With JUSTIFIED 01 A PIC X(6). 01 A PIC X(6) JUSTIFIED RIGHT. MOVE "ABCDEFGHI" TO A MOVE "ABCDEFGHI" TO A Result is ’ABCDEF’ Result is ’DEFGHI’ Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 151 5.9.25. LEFTLINE (cid:11) (cid:10) LEFTLINE ~~~~~~~~ LEFTLINE Attribute Syntax (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: SCREEN The "LEFTLINE" clause will introduce a vertical line at the left edge of a screen field. 1. The "LEFTLINE", "OVERLINE" (see [OVERLINE], page 161) and "UNDERLINE" (see [UNDERLINE], page 185) clauses may be used in any combination in a single field’s description. 2. This clause is essentially non-functional when used within Windows command shell (cmd.exe) environments and running programs compiled using a GNU COBOL imple- mentation built using ’PDCurses’ (such as Windows/MinGW builds). 3. Whether or not this clause operates on Cygwin or UNIX/Linux/OSX systems will depend upon the video attribute capabilities of the terminal output drivers and ’curses’ software being used. See [Color Palette and Video Attributes], page 20, for more information on screen colors and video attributes. 3 June 2014 Chapter 5 - DATA DIVISION 152 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 5.9.26. LENGTH-CHECK (cid:11) LENGTH-CHECK Attribute Syntax (cid:10) LENGTH-CHECK ~~~~~~~~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: SCREEN The "LENGTH-CHECK" clause forces the user to enter data into the field it is specified on (or into all subordinate input-capable fields if specified on a group item) sufficient to fill every character position of the field. 1. The "FULL" (see [FULL], page 145) and "LENGTH-CHECK" clauses are interchangeable, and may not be used together in the same data item description. 2. In order for this clause to take effect at execution time, the user must move the cursor into the field having this clause in its definition. 3. The "ACCEPT screen-data-item" statement [ACCEPT screen-data-item], page 342) will ignore the Enter key and any other cursor-moving keystrokes that would cause the cursor to move to another screen item unless the proper amount of data has been entered into the field. Function keys will still be allowed to terminate the "ACCEPT", however. (see 4. In order to be functional, this attribute must be supported by the underlying ’curses’ package your GNU COBOL implementation was built with. As of this time, the ’PDCurses’ package (used for native Windows or MinGW builds) does not support "LENGTH-CHECK". Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 153 5.9.27. LINE (cid:11) (cid:10) LINE (REPORT SECTION) Clause Syntax (cid:8) (cid:9) LINE NUMBER IS { integer-2 [ [ ON NEXT PAGE ] } } ~~~~ } } } { { +|PLUS integer-2 { { ON NEXT PAGE ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ———————————————————————————————————————— (cid:11) (cid:8) (cid:10) LINE (SCREEN SECTION) Clause Syntax (cid:9) [ LINE NUMBER IS [ +|PLUS ] integer-4 | identifier-6 ] ~~~~ ~~~~ ———————————————————————————————————————— This syntax is valid in the following sections: REPORT, SCREEN This clause provides a means of explicitly stating on which line a field should be presented on the console window (screen section) or on a report (report section). 1. The reserved words "IS", "NUMBER" and "ON" are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program. 2. The following points document the use of format 1 of the "LINE" clause: A. The column location of a report item will be determined by the "COLUMN" (see [COLUMN], page 136) clause. B. The value of must be 1 or greater. C. The report line number upon which the data item containing this clause along with any subordinate data items will be presented may be stated on an absolute basis (i.e. "LINE 5") or on a relative basis based upon the previously-displayed line (i.e. "LINE PLUS 1"). D. The symbol "+" may be used in lieue of the word "PLUS", if desired; if "+" is used, however, there must be at least one space separating it from . Failure to include this space will cause the "+" to be simply treated as part of and will treat the LINE clause as an absolute line specification rather than a relative one. E. The optional "NEXT PAGE" clause specifies that — regardless of whether or not the 3 June 2014 Chapter 5 - DATA DIVISION 154 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide report group containing this clause could fit on the report page being currently generated, the report group will be forced to appear on a new page. 3. The following points document the use for format 2 of the "LINE" clause: A. The column location of a screen section field is determined by the "COLUMN" (see [COLUMN], page 136) clause. B. The value of must be 1 or greater. C. If is used to specify either an absolute or relative column position, must be defined as a numeric item of any "USAGE" (see [USAGE], page 186) other than "COMPUTATIONAL-1" or "COMPUTATIONAL-2", without editing symbols. The value of at the time the screen data item is presented must be 1 or greater. Note that a "COMPUTATIONAL-1" or "COMPUTATIONAL-2" identifier will be accepted by the compiler, but will produce unpredictable results at run-time. D. The screen line number upon which the data item containing this clause along with any subordinate data items will be displayed may be stated on an absolute basis (i.e. "LINE 5") or on a relative basis based upon the previously-displayed line (i.e. "LINE PLUS 1"). E. The symbol "+" may be used in lieue of the word "PLUS", if desired; if "+" is used, however, there must be at least one space separating it from . Failure to include this space will cause the "+" to be simply treated as part of and will treat the "LINE" clause as an absolute line specification rather than a relative one. F. If a screen data item’s description includes the "FROM" (see [FROM], page 144), "TO" (see [TO], page 183), "USING" (see [USING], page 196) or "VALUE" (see [VALUE], page 197) clause but has no LINE clause, the "current screen line" will be assumed. Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 155 5.9.28. LOWLIGHT (cid:11) (cid:10) LOWLIGHT ~~~~~~~~ LOWLIGHT Attribute Syntax (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: SCREEN The "LOWLIGHT" clause controls the intensity of text ("FOREGROUND-COLOR") by setting that intensity to its lowest of three possible settings. 1. This clause, along with "HIGHLIGHT" (see [HIGHLIGHT], page 148), are intended to provide a three-level intensity scheme ("LOWLIGHT" . . . nothing (Normal) . . . "HIGHLIGHT"). In environments such as a Windows console where only two levels of intensity are supported, "LOWLIGHT" is the same as leaving this clause off altogether. See [Color Palette and Video Attributes], page 20, for more information on screen colors and video attributes. 3 June 2014 Chapter 5 - DATA DIVISION 156 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 5.9.29. NEXT GROUP (cid:11) (cid:10) NEXT-GROUP Clause Syntax (cid:8) (cid:9) NEXT GROUP IS { [ +|PLUS ] integer-2 ~~~~ ~~~~~ } } { { NEXT|{NEXT PAGE}|PAGE } ~~~~ ~~~~ ~~~~ ~~~~ ~~~~ ———————————————————————————————————————— This syntax is valid in the following sections: REPORT This clause defines any rules for where the next group to be presented on a report will begin, line-wise, with respect to the last line of the group in which this clause appears. 1. The reserved word "IS" is optional and may be included, or not, at the discretion of the programmer. The presence or absence of this word has no effect upon the program. 2. The terms "NEXT", "NEXT PAGE" and "PAGE" are interchangeable. 3. A report group must contain at least one "LINE NUMBER" clause in order to also contain a "NEXT GROUP" clause. 4. If the "RD" (see [REPORT SECTION], page 107) in which the report group containing a "NEXT GROUP" clause does not contain a "PAGE LIMITS" clause, only the "PLUS integer-1" option may be specified. 5. The "NEXT PAGE" option cannot be used in a "PAGE FOOTING". 6. The "NEXT GROUP" option cannot be specified in either a "REPORT HEADING" or a "PAGE HEADING". 7. The effects of "NEXT GROUP" will be in addition to any line spacing defined by the next-presented group’s "LINE NUMBER" clause. Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 157 5.9.30. NO-ECHO (cid:11) (cid:10) NO-ECHO ~~~~~~~ NO-ECHO Attribute Syntax (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: SCREEN The "NO-ECHO" clause will cause all data entered into the field to appear on the screen as asterisks. 1. The "NO-ECHO" and "SECURE" (see [SECURE], page 176) clauses are interchangeable, and may not be used together in the same data item description. 2. This clause may only be used on a field allowing data entry (a field containing either the "USING" (see [USING], page 196) or "TO" (see [TO], page 183) clause). See [Color Palette and Video Attributes], page 20, for more information on screen colors and video attributes. 3 June 2014 Chapter 5 - DATA DIVISION 158 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 5.9.31. OCCURS (cid:11) (cid:10) OCCURS (REPORT SECTION) Clause Syntax (cid:8) (cid:9) OCCURS [ integer-1 TO ] integer-2 TIMES ~~ ~~~~~~ [ DEPENDING ON identifier-1 ] ~~~~~~~~~ [ STEP integer-3 ] ~~~~ [ VARYING identifier-2 FROM { identifier-3 } BY { identifier-4 } ] ~~~~~~~ ~~~~ { integer-4 } ~~ { integer-5 } ———————————————————————————————————————— (cid:11) (cid:8) (cid:10) OCCURS (SCREEN SECTION) Clause Syntax (cid:9) OCCURS integer-2 TIMES ~~~~~~ ———————————————————————————————————————— (cid:11) (cid:8) (cid:10) OCCURS (All Other Sections Clause Syntax (cid:9) OCCURS [ integer-1 TO ] integer-2 TIMES ~~ ~~~~~~ [ DEPENDING ON identifier-1 ] ~~~~~~~~~ [ ASCENDING|DESCENDING KEY IS identifier-5... ]... ~~~~~~~~~ ~~~~~~~~~~ [ INDEXED BY identifier-6 ] ~~~~~~~ ———————————————————————————————————————— This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE, LINKAGE, REPORT, SCREEN The "OCCURS" clause is used to create a data structure called a table, where entries in that structure repeat multiple times. 1. The reserved words "BY" (INDEXED), "IS", "KEY", "ON" and "TIMES" are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program. 2. The value of specifies how many entries will be allocated in the table. 3. The following is an example of how a table might be defined: Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 159 05 QUARTERLY-REVENUE OCCURS 4 TIMES PIC 9(7)V99. This will allocate the following: QUARTERLY-REVENUE(1) QUARTERLY-REVENUE(2) QUARTERLY-REVENUE(3) QUARTERLY-REVENUE(4) Each occurrence is referenced using the subscript syntax (a numeric literal, arithmetic expression or numeric identifier enclosed within parenthesis) shown above. 4. The "OCCURS" clause may be used at the group level too, in which case the entire group structure repeats, as follows: 05 GRP OCCURS 3 TIMES. PIC X(1). PIC X(1). PIC X(1). 10 A 10 B 10 C This would allow references to any of the following: GRP(1) - includes A(1), B(1) and C(1) GRP(2) - includes A(2), B(2) and C(2) GRP(3) - includes A(3), B(3) and C(3) or each A,B,C item could be referenced as follows: A(1) - Character #1 of GRP(1) B(1) - Character #2 of GRP(1) C(1) - Character #3 of GRP(1) A(2) - Character #1 of GRP(2) B(2) - Character #2 of GRP(2) C(2) - Character #3 of GRP(2) A(3) - Character #1 of GRP(3) B(3) - Character #2 of GRP(3) C(3) - Character #3 of GRP(3) 5. The optional "DEPENDING ON" clause can be added to an "OCCURS" to create a variable- length table. In such cases, the value of specifies what the minimum number of entries in the table will be while specifies the maximum. Such tables will be allocated out to the maximum size specified as . At execution time the value of will determine how many of the table elements are accessible. 6. See the documentation of the "SEARCH" (see [SEARCH], page 440), "SEARCH ALL" (see [SEARCH ALL], page 442) and "SORT" (see [SORT], page 453) statements for explanations of the "KEY" and "INDEXED BY" clauses. 7. The "OCCURS" clause cannot be specified in a data description entry that has a level 3 June 2014 Chapter 5 - DATA DIVISION 160 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide number of 01, 66, 77, or 88, although it is valid in data items described subordinate to an 01-level data item. 8. The following points apply to an "OCCURS" used in the report section: A. The optional "STEP" clause defines an incrementation value that will be added to any absolute "LINE" (see [LINE], page 153) or "COLUMN" (see [COLUMN], page 136) number specifications that may be part of or subordinate to this data item’s definition. B. The optional "VARYING" clause defines an identifier that may be used as a sub- script for the multiple occurrences of this or any subordinate data item should the "SOURCE" (see [SOURCE], page 178) or "SUM" (see [SUM], page 326) clause(s) on this or subordinate data items reference entries within the table. The data item is dynamically created as needed and cannot be referenced outside the scope of the report data item definition. C. The following two examples illustrate two different ways a report could include four quarters worth of sales figures in it’s detail lines — one doing things ’the hard way’ and one using the advanced "OCCURS" capabilities of "STEP" and "VARYING". Both assume the definition of the following table exists in working-storage: 05 SALES OCCURS 4 TIMES PIC 9(7)V99. First, the "Hard Way": 10 COL 7 PIC $(7)9.99 SOURCE SALES(1). 10 COL 17 PIC $(7)9.99 SOURCE SALES(2). 10 COL 27 PIC $(7)9.99 SOURCE SALES(3). 10 COL 37 PIC $(7)9.99 SOURCE SALES(4). And then using "STEP" and "VARYING": 10 COL 7 OCCURS 4 TIMES STEP 10 VARYING QTR FROM 1 BY 1 PIC $(7)9.99 SOURCE SALES(QTR). Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 161 5.9.32. OVERLINE (cid:11) (cid:10) OVERLINE ~~~~~~~~ OVERLINE Attribute Syntax (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: SCREEN The "OVERLINE" clause will introduce a horizontal line at the top edge of a screen field. 1. The "LEFTLINE" (see [LEFTLINE], page 151), "OVERLINE" and "UNDERLINE" (see [UNDERLINE], page 185) clauses may be used in any combination in a single field’s description. 2. This clause is essentially non-functional when used within Windows command shell (cmd.exe) environments and running programs compiled using a GNU COBOL imple- mentation built using ’PDCurses’ (such as Windows/MinGW builds). 3. Whether or not this clause operates on Cygwin or UNIX/Linux/OSX systems will depend upon the video attribute capabilities of the terminal output drivers and ’curses’ software being used. See [Color Palette and Video Attributes], page 20, for more information on screen colors and video attributes. 3 June 2014 Chapter 5 - DATA DIVISION 162 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 5.9.33. PICTURE (cid:11) (cid:10) PICTURE IS picture-string ~~~ PICTURE Clause Syntax (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE, LINKAGE, REPORT, SCREEN The picture clause defines the class (numeric, alphabetic or alphanumeric), size and format of the data that may be contained by the data item being defined. Sometimes this role is assisted by the "USAGE" (see [USAGE], page 186) clause, and in a few instances will be assumed entirely by that clause. 1. The reserved word "IS" is optional and may be included, or not, at the discretion of the programmer. The presence or absence of this word has no effect upon the program. 2. The reserved word "PICTURE" may be abbreviated as "PIC". Most programmers prefer to use the latter. 3. A picture clause may only be specified on an elementary item. 4. A is a sequence of the special symbols "$", "*", "+", ",", "-", ".", "/", "0" (zero), "9", "A", "B", "CR", "DB", "S", "V", "X" and "Z". 5. In general, each picture symbol represents either a single character in storage or a single decimal digit. There are a few exceptions, and they will be discussed as needed. 6. When a contains a repeated sequence of symbols — "PIC 9999/99/99" — for example, the repetition can be specified using a parenthetic repeat count, as in "PIC 9(4)/9(2)/9(2)". Using repeat counts is optional and their use (or not) is entirely at the discretion of the programmer. Many programmers use repetition for small sequences ("PIC XXX") and repeat counts for larger ones ("PIC 9(9)". 7. This first set of picture symbols defines the basic data type of a data item. Each symbol represents a single character’s worth of storage. "A" "N" Defines storage reserved for a single alphabetic character ("A"-"Z", "a"- "z"). Defines storage reserved for a single character in the computer’s ’National Characterset’. Support for national charactersets in GNU COBOL is currently only partially implemented, and the compile- and run-time effect of using the "N" picture symbol is the same as if "X(2)" had been coded, with the additional effect that such a field will qualify as a "NATIONAL" or "NATIONAL-EDITED" field on an "INITIALIZE" (see [INITIALIZE], page 399) statement. Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 163 "X" "9" Defines storage reserved for a single alphanumeric character (any charac- ter). Defines storage reserved for a single numeric digit character ("0"-"9"). Typically, only one kind of each of those symbols is used in the same picture clause, but that isn’t a requirement. Data items that, of the three symbols above, use nothing but "A" picture symbols are known as ’Alphabetic Data Items’ while those that use "9" picture symbols without any "A" or "X" symbols (or those that have a "USAGE" without a "PICTURE") are known as ’Numeric Data Items’. All other data items are referred to as ’Alphanumeric Data Items’. If you need to allocate space for a data item whose format is two letters followed by five digits followed by three letters, you could use the "AA99999AAA", "A(2)9(5)A(3)" "XXXXXXXXXX" or "X(10)". There is absolutely no functional differ- ence whatsoever between the four — none of them provide any functionality the others do not. The first two probably make for better documentation of the expected field contents, but they don’t provide any run-time enforcement capabilities. As far as enforcement goes, however, both alphabetic and numeric picture strings do provide for both compile-time and run-time enforcement capabilities. In the case of compilation enforcement, the compiler can issue warning messages if you attempt to specify a non-numeric value for a numeric data item or if you attempt to "MOVE" (see [MOVE], page 414) a non-numeric data item to one that is numeric. Similar capabilities exist for alphabetic data items. At run-time, you may use a special class test (see [Class Conditions], page 219) to determine if the contents of a data item are entirely numeric or entirely alphabetic. 8. The following picture symbols may be used with numeric data items. "P" Defines an implied digit position that will be considered to be a zero when the data item is referenced at run-time. This symbol is used to allow data items that will contain very large values to be allocated using less storage by assuming a certain number of trailing zeros (one per "P") to exist at the end of values. The "P" symbol is not allowed in conjunction with "N". The "P" symbol may only be used at the beginning or end of a picture clause. "P" is a repeatable symbol. All computations and "MOVE" (see [MOVE], page 414) operations involving such a data item will behave as if the zeros were actually there. For example, let’s say you need to allocate a data item that contains how- ever many millions of dollars of revenue your company has in gross revenues this year: 3 June 2014 Chapter 5 - DATA DIVISION 164 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 01 Gross-Revenue PIC 9(9). In which case 9 characters of storage will be reserved. The values 000000000 thru 999999999 will represent the gross-revenues. But, if only the millions are tracked (meaning the last six digits are always going to be 0), you could define the field as: 01 Gross-Revenue PIC 9(3)P(6). Whenever Gross-Revenue is referenced in calculations, or whenever its value is moved to another data item, the value of Gross-Revenue will be treated as if it is nnn000000, where ’nnn’ is the actual value in storage. If you wanted to store the value 128 million into that field, you would do so as if the "P"s were "9"s: MOVE 128000000 TO Gross-Revenue A "DISPLAY" (see [DISPLAY], page 370) of a data item containing "P" symbols is a little strange. The value displayed will be what is actually in storage, but the total size of the displayed value will be as if the "P" symbols had been "9"s. Thus, after the above statement established a value for Gross-Revenue, a "DISPLAY Gross-Revenue" would produce output of ’000000128’. This symbol, if used, must be the very first symbol in the "PICTURE" value. A "S" indicates that the data item is "Signed", meaning that negative values are possible for this data item. Without an "S", any negative values stored into this data item via a "MOVE" or arithmetic statement will have the negative sign stripped from it (in effect becoming the absolute value). The "S" symbol is not allowed in conjunction with "N". The "S" symbol may only occur once in a picture string. See [SIGN IS], page 177, for further discussion of how negative values may be stored in a numeric data item. This symbol is used to define where an implied decimal-point (if any) is located in a numeric item. Just as there may only be a single decimal point in a number so may there be no more than one "V" in a "PICTURE". Implied decimal points occupy no space in storage — they just specify how values are used. For example, if the value "1234" is in storage in a field defined as PIC 999V9, that value would be treated as 123.4 in any statements that referenced it. The "V" symbol is not allowed in conjunction with "N". "S" "V" The "V" symbol may only occur once in a picture string. 9. Any editing symbols introduced past this point will, if coded in the picture clause of an otherwise numeric data item, transform that data item from a numeric to a ’Numeric Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 165 Edited ’ data item. Numeric edited data items are treated as alphanumeric and may not serve either as table subscripts or as source arguments on an arithmetic statement. 10. The following are the fixed insertion editing symbols that may be specified in a picture string. Each of these editing symbols will insert a special character into the field value at the position it is specified in the picture string. These editing symbols will each introduce one extra character into the total field size for each occurrence of the symbol in the picture string. "B" The "B" editing symbol introduces a blank into the field value for each occurrence. Multiple "B" symbols may be coded. The following example will format a ten digit number (presumably a tele- phone number) into a "### ### ####" layout: ... ... 05 Phone-Number PIC 9(3)B9(3)B9(4). MOVE 5185551212 TO Phone-Number DISPLAY Phone-Number This code will display "518 555 1212". "0" The "0" (zero) editing symbol introduces one "0" character into the field value for each occurrence in the picture string. Multiple "0" symbols may be coded. Here’s an example: ... ... 05 Output-Item PIC 909090909. MOVE 12345 TO Output-Item DISPLAY Output-Item The above will display "102030405". "/" The "/" editing symbol inserts one "/" character into the field value for each occurrence in the picture string. Multiple "/" symbols may be coded. This editing symbol is most-frequently used to format dates, as follows: ... ... 05 Year-Month-Day PIC 9(4)/9(2)/9(2). MOVE 20140207 TO Year-Month-Day 3 June 2014 Chapter 5 - DATA DIVISION 166 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide DISPLAY Year-Month-Day This example displays "2014/02/07". 11. The following are the numeric formatting symbols that may be specified in a picture string. Each of these editing symbols will insert special characters into the field value to present numbers in a "friendly" format. These editing symbols will each introduce one extra character into the total field size for each occurrence of the symbol in the picture string. Numeric fields whose picture clause contains these characters may neither be used as source fields in any calculation nor may they serve as source fields for the transfer of data values to any data item other than an alphanumeric field. "." The "." symbol inserts a decimal point into a numeric field value. When the contents of a numeric data item sending field are moved into a receiving data item whose picture clause contains the "." editing symbol, implied ("V") or actual decimal point in the sending data item or literal, respec- tively, will be aligned with the "." symbol in the receiving field. Digits are then transferred from the sending to the receiving field outward from the sending field’s "V" or ".", truncating sending digits if there aren’t enough positions in the receiving field. Any digit positions in the receiving field that don’t receive digits from the sending field, if any, will be set to 0. The "." symbol is not allowed in conjunction with "N". An example will probably help: PIC 9(2)V9 VALUE 7.2. PIC 9(5).9(2). ... 05 Source-Field 05 Dest-Field ... MOVE 1234567.89 TO Dest-Field DISPLAY Dest-Field MOVE 19 TO Dest-Field DISPLAY Dest-Field MOVE Source-Field TO Dest-Field DISPLAY Dest-Field The example will display three results — "34567.89", "00019.00" and "00007.20". Both data item definitions appear to have two decimal points in their pic- ture clauses. They actually don’t, because the last character of every data item definition is always a period — the period that ends the definition. "," The "," symbol serves as a thousands separator. Many times, you’ll see large numbers formatted with these symbols — for example, 123,456,789. This can be accomplished easily by adding thousands separator symbols to a picture string. Thousands separator symbols that aren’t needed will behave as if they were "9"s. Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 167 The "," symbol is not allowed in conjunction with "N". Here’s an example: ... 05 My-Lottery-Winnings ... MOVE 12345 TO My-Lottery-Winnings DISPLAY My-Lottery-Winnings PIC 9(3),9(3),9(3). The value "0000012,345" (a very disappointing one for my retirement plans, but a good thousands separator demo) will be displayed. Notice how, since the first comma wasn’t needed due to the meager amount I won, it behaved like another "9". If desired, you may reverse the roles of the "." and "," editing symbols by speci- fying "DECIMAL POINT IS COMMA" in the "SPECIAL-NAMES" (see [SPECIAL-NAMES], page 62) paragraph. 12. The following are insertion symbols. They are used to insert an extra character (two in the case of "CR" and "DB") to signify the sign (positive or negative) of the numeric value that is moved into the field whose picture string contains one of these symbols, or the fact that the data item represents a currency (money) amount. Only one of the "+", "-", "CR" or "DB" symbols may be used in a picture clause. In this context, when any of these symbols are used in a , they must be at the end. The "+", "-" and/or currency symbols may also be used as floating editing symbols at the beginning of the — a subject that will be covered in the next numbered paragraph. "+" "-" "CR" If the value of the numeric value moved into the field is positive (0 or greater), a "+" character will be inserted. If the value is negative (less than 0), a "-" character is inserted. The "+" symbol is not allowed in conjunction with "N". If the value of the numeric value moved into the field is positive (0 or greater), a space will be inserted. If the value is negative (less than 0), a "-" character is inserted. The "-" symbol is not allowed in conjunction with "N". This symbol is coded as the two characters "C" and "R". If the value of the numeric value moved into the field is positive (0 or greater), two spaces will be inserted. If the value is negative (less than 0), the characters "CR" (credit) are inserted. The "CR" symbol is not allowed in conjunction with "N". 3 June 2014 Chapter 5 - DATA DIVISION 168 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide "DB" "$" This symbol is coded as the two characters "D" and "B". If the value of the numeric value moved into the field is positive (0 or greater), two spaces will be inserted. If the value is negative (less than 0), the characters "DB" (debit) are inserted. The "DB" symbol is not allowed in conjunction with "N". Regardless of the value moved into the field, this symbol will insert the currency symbol into the data item’s value in the position where it occurs in the (see [SPECIAL-NAMES], page 62). The "$" symbol is not allowed in conjunction with "N". 13. These editing symbols are known as floating replacement symbols. These symbols may occur in sequences before any "9" editing symbols in the of a numeric data item. Using these symbols transforms that numeric data item into a numerid edited data item, which can no longer be used in calculations or subscripts. 14. Each of the following symbols behave like a "9", until such point as all digits in the numeric value are exhausted and leading zeros are about to be inserted. In effect, these editing symbols define what should happen to those leading zero. "$" "*" "+" Of those currency symbols that correspond to character positions in which leading zeros reside, the right-most will have its "0" value replaced by the currency symbol in-effect for the program (see [SPECIAL-NAMES], page 62). Any remaining leading zero values occupying positions described by this symbol will be replaced by spaces. The "$" symbol is not allowed in conjunction with "N". Any currency symbol coded to the right of a "." will be treated exactly like a "9". This symbol is referred to as a check protection symbol. All check- protection symbols that correspond to character positions in which leading zeros reside will have their "0" values replaced by "*". The "*" symbol is not allowed in conjunction with "N". Any check-suppression symbol coded to the right of a "." will be treated exactly like a "9". Of those "+" symbols that correspond to character positions in which lead- ing zeros reside, the right-most will have its "0" value replaced by a "+" if the value in the data item is zero or greater or a "-" otherwise. Any re- maining leading zero values occupying positions described by this symbol will be replaced by spaces. You cannot use both "+" and "-" in the same . The "+" symbol is not allowed in conjunction with "N". Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 169 "-" Any "+" symbol coded to the right of a "." will be treated exactly like a "9". Of those "-" symbols that correspond to character positions in which lead- ing zeros reside, the right-most will have its "0" value replaced by a space if the value in the data item is zero or greater or a "-" otherwise. Any re- maining leading zero values occupying positions described by this symbol will be replaced by spaces. You cannot use both "+" and "-" in the same . The "-" symbol is not allowed in conjunction with "N". Any "-" symbol coded to the right of a "." will be treated exactly like a "9". "Z" All "Z" symbols that correspond to character positions in which leading zeros reside will have their "0" values replaced by spaces. Any zero-suppression symbol coded to the right of a "." will be treated exactly like a "9". "Z" and "*" should not be coded in the same "+" and "-" should not be coded in the same When multiple floating symbols are coded, even if there is only one of them used they will all be considered floating and will all be able to assume each other’s properties. For example, if a data item has a "PIC +$ZZZZ9.99" , and a value of 1 is moved to that field at run-time, the resulting value will be (the b symbol represents a space) "bbbb+$1.00". This is not consistent with many other COBOL implementations, where the result would have been "+$bbbb1.00". Most other COBOL implementations reject the use of multiple occurrences of multiple floating editing symbols. For example, they would reject s such as "+++$$$9.99", "$$$ZZZ9.99" and so on. GNU COBOL accepts these. Programmers creating GNU COBOL programs should avoid such s if there is any liklihood that those programs may be used with other COBOL implementations. 3 June 2014 Chapter 5 - DATA DIVISION 170 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 5.9.34. PRESENT WHEN (cid:11) (cid:10) PRESENT-WHEN Clause Syntax PRESENT WHEN condition-name ~~~~~~~ ~~~~ (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: REPORT This clause names an existing "Condition Name" (see [Condition Names], page 218) that will serve as a switch controlling the presentation or suppression of a report group. 1. If the specified condition-name has a value of FALSE when a "GENERATE" statement (see [GENERATE], page 391) causes a report group to be presented, the presentation of that group will be suppressed. 2. If the condition-name has a value of TRUE, the group will be presented. 3. See [Condition Names], page 218, for more information. Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 171 5.9.35. PROMPT (cid:11) (cid:10) PROMPT Clause Syntax PROMPT [ CHARACTER IS literal-1 | identifier-1 ] ~~~~~~ ~~~~~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: SCREEN This clause defines the character that will be used as the fill-character for any input fields on the screen. 1. The reserved word "IS" is optional and may be included, or not, at the discretion of the programmer. The presence or absence of this word has no effect upon the program. 2. The default prompt character, should no "CHARACTER" specification be coded, or should the "PROMPT" clause be absent altogether, is an underscore (" "). 3. Prompt characters will be automatically transformed into spaces upon input. See [Color Palette and Video Attributes], page 20, for more information on screen colors and video attributes. 3 June 2014 Chapter 5 - DATA DIVISION 172 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 5.9.36. REDEFINES (cid:11) (cid:10) REDEFINES identifier-1 ~~~~~~~~~ REDEFINES Clause Syntax (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE, LINKAGE The "REDEFINES" clause causes the data item in who’s definition the "REDEFINES" clause is specified (hereafter referred to as the redefines object) to occupy the same physical storage space as (hereafter referred to as the redefines subject). 1. The following rules must all be followed in order to use REDEFINES: A. The level number of both the subject and object data items must be the same. B. The level numbers of both the subject and object data items cannot be 66, 78 or 88. C. If "n" represents the level number of the object, then no other data items with level number "n" may be defined between the subject and object data items unless they too are "REDEFINES" of the subject. D. If "n" represents the level number of the object, then no other data items with a level number numerically less than "n" may be defined between the subject and object data items. E. The total allocated size of the subject data item must be the same as the total allocated size of the object data item. F. No "OCCURS" (see [OCCURS], page 158) clause may be part of the definition of either the subject or object data items. Either or both, however, may be group items that contain data items with "OCCURS" clauses. G. No "VALUE" (see [VALUE], page 197) clause may be defined on the object data item, and no data items subordinate to the object data item may have "VALUE" clauses, with the exception of level-88 condition names. Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 173 5.9.37. RENAMES (cid:11) (cid:10) RENAMES Clause Syntax RENAMES identifier-1 [ THRU|THROUGH identifier-2 ~~~~~~~ ~~~~ ~~~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE, LINKAGE The "RENAMES" clause regroups previously defined items by specifying alternative, possibly overlapping, groupings of elementary data items. 1. The reserved words "THRU" and "THROUGH" are interchangeable. 2. You must use the level number 66 for data description entries that contain the "RENAMES" clause. 3. The and data items, along with all data items defined between those two data items in the program source, must all be contained within the same 01-level record description. 4. See [66-Level Data Items], page 121, for additional information on the RENAMES clause. 3 June 2014 Chapter 5 - DATA DIVISION 174 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 5.9.38. REQUIRED (cid:11) (cid:10) REQUIRED ~~~~~~~~ REQUIRED Attribute Syntax (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: SCREEN This clause forces the user to enter data into the field it is specified on (or into all subordinate input-capable fields if "REQUIRED" is specified on a group item). 1. The "EMPTY-CHECK" (see [EMPTY-CHECK], page 139) and "REQUIRED" clauses are interchangeable, and may not be used together in the same data item description. 2. In order to take effect, the user must first move the cursor into the field having this clause in its definition. 3. The "ACCEPT screen-data-item" statement [ACCEPT screen-data-item], page 342) will ignore the Enter key and any other cursor-moving keystrokes that would cause the cursor to move to another screen item unless data has been entered into the field. Function keys will still be allowed to terminate the "ACCEPT". (see 4. In order to be functional, this attribute must be supported by the underlying ’curses’ package your GNU COBOL implementation was built with. As of this time, the ’PDCurses’ package (used for native Windows or MinGW builds) does not support "REQUIRED". Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 175 5.9.39. REVERSE-VIDEO (cid:11) REVERSE-VIDEO Attribute Syntax (cid:10) REVERSE-VIDEO ~~~~~~~~~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: SCREEN The "REVERSE-VIDEO" attribute swaps the specified or implied "FOREGROUND-COLOR" (see [FOREGROUND-COLOR], page 143) and "BACKGROUND-COLOR" (see [BACKGROUND- COLOR], page 129) attributes for the field whose definition contains this clause (or all subordinate fields if used on a group item). See [Color Palette and Video Attributes], page 20, for more information on screen colors and video attributes. 3 June 2014 Chapter 5 - DATA DIVISION 176 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 5.9.40. SECURE (cid:11) (cid:10) SECURE ~~~~~~ SECURE Attribute Syntax (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: SCREEN This clause will cause all data entered into the field to appear on the screen as asterisks. 1. The "NO-ECHO" (see [NO-ECHO], page 157) and "SECURE" clauses are interchangeable, and may not be used together in the same data item description. 2. This clause may only be used on a field allowing data entry (a field containing either the "USING" (see [USING], page 196) or "TO" (see [TO], page 183) clause). See [Color Palette and Video Attributes], page 20, for more information on screen colors and video attributes. Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 177 5.9.41. SIGN IS (cid:11) (cid:10) SIGN-IS Clause Syntax (cid:8) (cid:9) SIGN IS LEADING|TRAILING [ SEPARATE CHARACTER ] ~~~~ ~~~~~~~ ~~~~~~~~ ~~~~~~~~ ———————————————————————————————————————— This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE, LINKAGE, REPORT, SCREEN This clause, allowable only for "USAGE DISPLAY" numeric data items, specifies how an "S" symbol will be interpreted in a data item’s picture clause. 1. The reserved words "CHARACTER" and "IS" are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program. 2. Without the "SEPARATE CHARACTER" option, the sign of the data item’s value will be encoded by transforming the last ("TRAILING") or first ("LEADING") digit as follows: First/Last Digit 0 1 2 3 4 5 6 7 8 9 Value For Positive 0 1 2 3 4 5 6 7 8 9 Value for Negative p q r s t u v w x y 3. If the "SEPARATE CHARACTER" clause is used, then an actual "+" or "-" character will be inserted into the field’s value as the first ("LEADING") or last ("TRAILING") character. Note that having this character imbedded within the data item’s storage does not prevent the data item from being used as a source field in arithmetic operations. 4. When "SEPARATE CHARACTER" is specified, the "S" symbol in the data item’s "PICTURE" must be counted when determining the data item’s size. 5. Neither the presence of an encoded digit (see above) nor an actual "+" or "-" character imbedded within the data item’s storage prevents the data item from being used as a source field in arithmetic operations. 3 June 2014 Chapter 5 - DATA DIVISION 178 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 5.9.42. SOURCE (cid:11) (cid:10) SOURCE Clause Syntax SOURCE IS literal-1 | identifier-1 [ ROUNDED ] ~~~~~~ ~~~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: REPORT This clause logically attaches a report section data item to another data item defined else- where in the data division. 1. The reserved word "IS" is optional and may be included, or not, at the discretion of the programmer. The presence or absence of this word has no effect upon the program. 2. When the report group containing this clause is presented, the value of the specified numeric literal or identifier will be automatically moved to the report data item prior to presentation. 3. The specified identifier may be defined anywhere in the data division, but if it is defined in the report section it may only be "PAGE-COUNTER", "LINE-COUNTER" or a "SUM" (see [SUM], page 326) counter. 4. The "PICTURE" (see [PICTURE], page 162) of the report data item must be such that it would be legal to "MOVE" (see [MOVE], page 414) the specified literal or identifier to a data item with that "PICTURE". 5. The "ROUNDED" option comes into play should the number of digits to the right of an actual or assumed decimal point be different between the specified literal or identifier value (the "source value") and the "PICTURE" specified for the field in whose definition the "SOURCE" clause appears (the "target field"). Without "ROUNDED", excess digits in the source value will simply be truncated to fit the target field. With "ROUNDED", the source value will be arithmetically rounded to fit the target field. See [ROUNDED], page 240, for information on the "NEAREST-AWAY-FROM-ZERO" rounding rule, which is the one that will apply. Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 179 5.9.43. SUM OF (cid:11) (cid:10) SUM-OF Clause Syntax (cid:8) (cid:9) SUM OF { identifier-7 }... [ { RESET ON FINAL|identifier-8 } ] ~~~ { literal-2 ~~~~~ } { ~~~~~ { UPON identifier-9 } } ~~~~ ———————————————————————————————————————— This syntax is valid in the following sections: REPORT The "SUM" clause establishes a summation counter whose value will be arithmetically cal- culated whenever the field is presented. 1. The reserved words "OF" and "ON" are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program. 2. The "SUM" clause may only appear in a "CONTROL FOOTING" report group. 3. If the data item in which the "SUM" clause appears has been assigned it’s own identifier name, and that name is not "FILLER", then that data item is referred to as a sum counter. 4. All data items must be non-edited numeric in nature. 5. If any data item is defined in the report section, it must be a sum counter. 6. Any data items that are sum counters must either be defined in the same report group as the data item in which this "SUM" clause appears or they must be defined in a report data item that exists at a lower level in this report’s control hierarchy. See [Control Hierarchy], page 488, for additional information. 7. The "PICTURE" of the report data item in who’s description this "SUM" clause appears in must be such that it would be legal to "MOVE" (see [MOVE], page 414) the specified or value to a data item with that "PICTURE". 8. The following points apply to the "UPON" option: A. The data item must be the name of a detail group specified in the same report as the control footing group in which this "SUM" clause appears. B. The presence of an "UPON" clause limits the "SUM" clause to adding the specified numeric literal or identifier value into the sum counter only when a "GENERATE " statement is executed. C. If there is no "UPON" clause specified, the value of or will be added into the sum counter whenever a "GENERATE" (see [GENERATE], page 391) of any detail report group in the report is executed. 3 June 2014 Chapter 5 - DATA DIVISION 180 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide D. If there is only a single detail group in the report’s definition, the "UPON" clause is meaningless. 9. The following points apply to the "RESET" option: A. If the "RESET" option is coded, "FINAL" or (whichever is coded on the "RESET") must be one of the report’s control breaks specified on the "CONTROLS" clause. B. If there is no "RESET" option coded, the sum counter will be reset back to zero after each time the control footing containing the "SUM" clause is presented. This is the typical behavior that would be expected. C. If, however, you want to reset the "SUM" counter only when the control footing for a control break higher in the control hierarchy is presented, specify that higher control break on the "RESET" option. Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 181 5.9.44. SYNCRONIZED (cid:11) (cid:10) SYNCRONIZED Syntax (cid:8) (cid:9) SYNCRONIZED|SYNCHRONISED [ LEFT|RIGHT ] ~~~~ ~~~~ ~~~~~ ~~~~ The "LEFT" and "RIGHT" (SYNCRONIZED) clauses are syntactically recognized but are otherwise non-functional. ———————————————————————————————————————— This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE, LINKAGE This optional clause optimizes the storage of binary numeric items to store them in such a manner as to make it as fast as possible for the CPU to fetch them. 1. The reserved words "SYNCRONIZED" and "SYNCHRONISED" are interchangeable, and may be abbreviated as "SYNC". 2. If the "SYNCRONIZED" clause is coded on anything but a numeric data item with a "USAGE" (see [USAGE], page 186) that specifies storage of data in a binary form, the "SYNCRONIZED" clause will be ignored. 3. Synchronization is performed (by the compiler) as follows: A. If the binary item occupies one byte of storage, no synchronization is performed. B. If the binary item occupies two bytes of storage, the binary item is allocated at the next half-word boundary. C. If the binary item occupies four bytes of storage, the binary item is allocated at the next word boundary. D. If the binary item occupies four bytes of storage, the binary item is allocated at the next word boundary. The following illustrates the allocation of a group of data items both without and with the "SYNCRONIZED" option. The grey blocks represent the unused bytes that are allocated in the Group-Item-2 structure because of the "SYNC" clauses. 3 June 2014 Chapter 5 - DATA DIVISION 182 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 183 5.9.45. TO (cid:11) (cid:10) TO identifier-5 ~~ TO Clause Syntax (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: SCREEN This clause logically attaches a screen section data item to another data item defined else- where in the data division. 1. The "TO" clause is used to define a data-entry field with no initial value; when a value is entered, it will be saved to the specified identifier. 2. The "FROM" (see [FROM], page 144), "TO", "USING" (see [USING], page 196) and "VALUE" (see [VALUE], page 197) clauses are mutually-exclusive in any screen section data itsm’s definition. 3 June 2014 Chapter 5 - DATA DIVISION 184 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 5.9.46. TYPE (cid:11) (cid:10) TYPE Clause Syntax (cid:8) (cid:9) [ TYPE IS { RH|{REPORT HEADING} ~~~~ } ] } { ~~ ~~~~~~ ~~~~~~~ } { PH|{PAGE HEADING} { ~~ ~~~~ ~~~~~~~ } { CH|{CONTROL HEADING} FINAL|identifier-2 } } { ~~ ~~~~~~~ ~~~~~~~ } { DE|DETAIL { ~~ ~~~~~~ } { CF|{CONTROL FOOTING} FINAL|identifier-2 } } { ~~ ~~~~~~~ ~~~~~~~ } { PF|{PAGE FOOTING} } { ~~ ~~~~ ~~~~~~~ { RF|{REPORT FOOTING} } ~~ ~~~~~~ ~~~~~~~ ~~~~~ ~~~~~ ———————————————————————————————————————— This syntax is valid in the following sections: REPORT This clause defines the type of report group that is being defined for a report. 1. This clause is required on any 01-level data item definitions (other than 01-level con- stants) in the report section. This clause is invalid on any other report section data item definitions. 2. There may be a maximum of one (1) report group per "RD" defined with a "TYPE" of "REPORT HEADING", "PAGE HEADING", "PAGE FOOTING" and "REPORT FOOTING". 3. There must be either a "CONTROL HEADING" or a "CONTROL FOOTING" or both specified for each entry specified on the "CONTROLS ARE" clause of the "RD". 4. The various report groups that constitute a report may be defined in any order. 5. See [RWCS Lexicon], page 483, for a description of the seven different types of report groups. Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 185 5.9.47. UNDERLINE (cid:11) (cid:10) UNDERLINE ~~~~~~~~~ UNDERLINE Attribute Syntax (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: SCREEN The "UNDERLINE" clause will introduce a horizontal line at the bottom edge of a screen field. 1. The "LEFTLINE" (see [LEFTLINE], page 151), "OVERLINE" (see [OVERLINE], page 161) and "UNDERLINE" clauses may be used in any combination in a single field’s description. 2. This clause is essentially non-functional when used within Windows command shell (cmd.exe) environments and running programs compiled using a GNU COBOL imple- mentation built using ’PDCurses’ (such as Windows/MinGW builds). 3. Whether or not this clause operates on Cygwin or UNIX/Linux/OSX systems will depend upon the video attribute capabilities of the terminal output drivers and ’curses’ software being used. See [Color Palette and Video Attributes], page 20, for more information on screen colors and video attributes. 3 June 2014 Chapter 5 - DATA DIVISION 186 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 5.9.48. USAGE (cid:11) (cid:10) USAGE IS data-item-usage ~~~~~ USAGE Clause Syntax (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE, LINKAGE, REPORT The "USAGE" clause defines the format that will be used to store the value of a data item. 1. The reserved word "IS" is optional and may be included, or not, at the discretion of the programmer. The presence or absence of this word has no effect upon the program. 2. The following table summarizes the various USAGE specifications available in GNU COBOL. BINARY ~~~~~~ Range of Values: Defined by the quantity of "9"s and the presence or absence of an "S" in the "PICTURE" Storage Format: Compatible Binary Integer Negative Values Allowed?: If "PICTURE" contains "S" "PICTURE" Used?: Yes BINARY-C-LONG [ SIGNED ] ~~~~~~~~~~~~~ Same as "BINARY-DOUBLE SIGNED" BINARY-C-LONG UNSIGNED ~~~~~~~~~~~~~ ~~~~~~~~ Range of Values: Typically 0 to 4,294,967,295 Storage Format: Native Binary Integer Negative Values Allowed?: "PICTURE" Used?: No No Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 187 BINARY-CHAR [ SIGNED ] ~~~~~~~~~~~ Range of Values: -128 to 127 Storage Format: Native Binary Integer Negative Values Allowed?: "PICTURE" Used?: Yes No BINARY-CHAR UNSIGNED ~~~~~~~~~~~ ~~~~~~~~ Range of Values: 0 to 255 Storage Format: Native Binary Integer Negative Values Allowed?: "PICTURE" Used?: No No BINARY-DOUBLE [ SIGNED ] ~~~~~~~~~~~~~ Range of Values: -9,223,372,036,854,775,808 9,223,372,036,854,775,807 to Storage Format: Native Binary Integer Negative Values Allowed?: "PICTURE" Used?: Yes No BINARY-DOUBLE UNSIGNED ~~~~~~~~~~~~~ ~~~~~~~~ Range of Values: 0 to 18,446,744,073,709,551,615 Storage Format: Native Binary Integer Negative Values Allowed?: "PICTURE" Used?: No No 3 June 2014 Chapter 5 - DATA DIVISION 188 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide BINARY-INT ~~~~~~~~~~ Same as "BINARY-LONG SIGNED" BINARY-LONG [ SIGNED ] ~~~~~~~~~~~ Range of Values: -2,147,483,648 2,147,483,647 Storage Format: Native Binary Integer Negative Values Allowed?: "PICTURE" Used?: Yes No BINARY-LONG UNSIGNED ~~~~~~~~~~~ ~~~~~~~~ Range of Values: 0 to 4,294,967,295 Storage Format: Native Binary Integer Negative Values Allowed?: "PICTURE" Used?: No No BINARY-LONG-LONG ~~~~~~~~~~~~~~~~ Same as "BINARY-DOUBLE SIGNED" BINARY-SHORT [ SIGNED ] ~~~~~~~~~~~~ Range of Values: -32,768 to 32,767 Storage Format: Native Binary Integer Negative Values Allowed?: "PICTURE" Used?: Yes No Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 189 BINARY-SHORT UNSIGNED ~~~~~~~~~~~~ ~~~~~~~~ Range of Values: 0 to 65,535 Storage Format: Native Binary Integer Negative Values Allowed?: "PICTURE" Used?: No No COMPUTATIONAL ~~~~ Same as "BINARY" COMP[UTATIONAL]-1 ~~~~ ~~ Same as "FLOAT-SHORT" COMP[UTATIONAL]-2 ~~~~ ~~ Same as "FLOAT-LONG" COMP[UTATIONAL]-3 ~~~~ ~~ Same as "PACKED-DECIMAL" COMP[UTATIONAL]-4 ~~~~ ~~ Same as "BINARY" COMP[UTATIONAL]-5 ~~~~ ~~ Range of Values: Depends on number of "9"s in the "PICTURE" and the "binary-size" setting of the configu- ration file used to compile the program 3 June 2014 Chapter 5 - DATA DIVISION 190 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide Storage Format: Native Binary Integer Negative Values Allowed?: If "PICTURE" contains "S" "PICTURE" Used?: Yes COMP[UTATIONAL]-6 ~~~~ ~~ Range of Values: Defined by the quantity of "9"s and the presence or absence of an "S" in the "PICTURE" Storage Format: Unsigned Packed Decimal Negative Values Allowed?: "PICTURE" Used?: No Yes COMP[UTATIONAL]-X ~~~~ ~~ Range of Values: If used with "PIC X", allocates one byte of stor- age per "X"; range of values is 0 to max storable in that many bytes. If used with "PIC 9", range of values depends on number of "9"s in PIC- TURE Storage Format: Native unsigned (X) or signed (9) Binary Negative Values Allowed?: If "PICTURE" 9 and contains "S" "PICTURE" Used?: Yes DISPLAY ~~~~~~~ Range of Values: Depends on "PICTURE" One character per X, A, 9, period, $, Z, 0, *, S (if "SEPARATE in CHARACTER" specified), +, "PICTURE"; Add 2 more bytes if the "DB" or "CR" editing symbol is used - or B symbol Storage Format: Characters Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 191 Negative Values Allowed?: If "PICTURE" contains "S" "PICTURE" Used?: Yes FLOAT-DECIMAL-16 ~~~~~~~~~~~~~~~~ Range of Values: 9.99999999999999910^384 9.99999999999999910^384 to Storage Format: Native IEEE 754 Decimal64 Floating-point Negative Values Allowed?: "PICTURE" Used?: Yes No FLOAT-DECIMAL-34 ~~~~~~~~~~~~~~~~ Range of Values: -9.99999...10^6144 to 9.99999...10^6144 Storage Format: Native IEEE 754 Decimal128 Floating-point Negative Values Allowed?: "PICTURE" Used?: Yes No FLOAT-LONG ~~~~~~~~~~ Range of Values: Approximately -1.79769313486231610^308 to 1.79769313486231610^308 Storage Format: Native IEEE 754 Binary64 Floating-point Negative Values Allowed?: "PICTURE" Used?: Yes No FLOAT-SHORT ~~~~~~~~~~~ Range of Values: Approximately 3.402823510^38 -3.402823510^38 to 3 June 2014 Chapter 5 - DATA DIVISION 192 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide Storage Format: Native IEEE 754 Binary32 Negative Values Allowed?: "PICTURE" Used?: Yes No INDEX ~~~~~ Range of Values: 0 to maximum address possible (32 or 64 bits) Storage Format: Native Binary Integer Negative Values Allowed?: "PICTURE" Used?: No No NATIONAL ~~~~~~~~ "USAGE NATIONAL", while syntactically recognized, COBOL is not supported by GNU PACKED-DECIMAL ~~~~~~~~~~~~~~ Range of Values: Defined by the quantity of "9"s and the presence or absence of an "S" in the PICTURE Storage Format: Signed Packed Decimal Negative Values Allowed?: If "PICTURE" contains "S" "PICTURE" Used?: No POINTER ~~~~~~~ Range of Values: 0 to maximum address possible (32 or 64 bits) Storage Format: Native Binary Integer Negative Values Allowed?: "PICTURE" Used?: No No Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 193 PROCEDURE-POINTER ~~~~~~~~~~~~~~~~~ Same as "PROGRAM-POINTER" PROGRAM-POINTER ~~~~~~~~~~~~~~~ Range of Values: 0 to maximum address possible (32 or 64 bits) Storage Format: Native Binary Integer Negative Values Allowed?: "PICTURE" Used?: No No SIGNED-INT ~~~~~~~~~~ Same as "BINARY-LONG SIGNED" SIGNED-LONG ~~~~~~~~~~~ Same as "BINARY-DOUBLE SIGNED" SIGNED-SHORT ~~~~~~~~~~~~ Same as "BINARY-SHORT SIGNED" UNSIGNED-INT ~~~~~~~~~~~~ Same as "BINARY-LONG UNSIGNED" UNSIGNED-LONG ~~~~~~~~~~~~~ Same as "BINARY-DOUBLE UNSIGNED" UNSIGNED-SHORT ~~~~~~~~~~~~~~ 3 June 2014 Chapter 5 - DATA DIVISION 194 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide Same as "BINARY-SHORT UNSIGNED" 3. Binary data (integer or floating-point) can be stored in either a Big-Endian or Little- Endian form. Big-endian data allocation calls for the bytes that comprise a binary item to be allocated such that the least-significant byte is the right-most byte. For example, a four-byte binary item having a value of decimal 20 would be big-endian allocated as 00000014 (shown in hexadecimal notation). Little-endian data allocation calls for the bytes that comprise a binary item to be allocated such that the least-significant byte is the left-most byte. For example, a four-byte binary item having a value of decimal 20 would be little-endian allocated as 14000000 (shown in hexadecimal notation). All CPUs are capable of "understanding" big-endian format, which makes it the "most-compatible" form of binary storage across computer systems. such as the Intel/AMD i386/x64 architecture processors used in most Some CPUs Windows PCs prefer to process binary data stored in a little-endian format. Since that format is more efficient on those systems, it is referred to as the "native" binary format. On a system supporting only one format of binary storage (generally, that would be big-endian), the terms ’most-efficient’ and ’native format’ are synonymous. 4. Data items that have the "UNSIGNED" attribute explicitly coded, or "DISPLAY", "PACKED-DECIMAL", "COMP-5", "COMP-X" items that do not have an "S" symbol in their picture clause cannot preserve negative values that may be stored into them. Storing a negative value into such a field will actually result in the sign being stripped, essentially saving the absolute value in the data item. 5. Packed-decimal (i.e. "USAGE PACKED-DECIMAL", "USAGE COMP-3" or "USAGE COMP-6") data is stored as a series of bytes such that each byte contains two 4-bit fields, referred to as ’nibbles’ (since they comprise half a "byte", they’re just "nibbles" — don’t groan, I don’t just make this stuff up!). Each nibble represents a "9" in the "PICTURE" and each holds a single decimal digit encoded as its binary value (0 = 0000, 1 = 0001, . . . , 9 = 1001). The last byte of a "PACKED-DECIMAL" or "COMP-3" data item will always have its left nibble corresponding to the last "9" in the "PICTURE" and its right nibble reserved as a sign indicator. This sign indicator is always present regardless of whether or not the "PICTURE" included an "S" symbol. The first byte of the data item will contain an unused left nibble if the "PICTURE" had an even number of "9" symbols in it. The sign indicator will have a value of a hexadecimal A thru F. Traditional packed decimal encoding rules call for hecadecimal values of F, A, C or E ("FACE") in the Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 195 sign nibble to indicate a positive value and B or D to represent a negative value (hex- adecimal digits 0-9 are undefined). Testing with a Windows MinGW/GNU COBOL implementation shows that – in fact – hex digit D represents a negative number and any other hexadecimal digit denotes a positive number. Therefore, a "PIC S9(3) COMP-3" packed-decimal field with a value of -15 would be stored internally as a hexadecimal 015D in GNU COBOL. If you attempt to store a negative number into a packed decimal field that has no "S" in its "PICTURE", the absolute value of the negative number will actually be stored. "USAGE COMP-6" does not allow for negative values, therefore no sign nibble will be allocated. A "USAGE COMP-6" data item containing an odd number of "9" symbols in its "PICTURE" will leave its leftmost nibble unused. 6. The "USAGE" specifications "FLOAT-DECIMAL-16" and "FLOAT-DECIMAL-34" will en- code data using IEEE 754 "Decimal64" and "Decimal128" format, respectively. The former allows for up to 16 digits of exact precision while the latter offers 34. The phrase "exact precision" is used because the traditional binary renderings of decimal real numbers in a floating-point format ("FLOAT-LONG" and "FLOAT-SHORT", for exam- ple) only yield an approximation of the actual value because many decimal fractions cannot be precisely rendered in binary. The Decimal64 and Decimal128 renderings, however, render decimal real numbers in encoded decimal form in much the same way that "PACKED-DECIMAL" renders a decimal integer in digit-by-digit decimal form. The exact manner in which this rendering is performed is complex (Wikipedia has an ex- cellent article on the subject just search for "Decimal64"). 7. GNU COBOL stores "FLOAT-DECIMAL-16" and "FLOAT-DECIMAL-34" data items using either Big-Endian or Little-Endian form, whichever is native to the system. 8. The "USAGE" specifications "FLOAT-LONG" and "FLOAT-SHORT" use the IEEE 754 "Binary64" and "Binary32" formats, respectively. These are binary encodings of real decimal numbers, and as such cannot represent every possible value between the minimum and maximum values in the range for those usages. Wikipedia has an excellent article on the Binary64 and Binary32 encoding schemes just search on "Binary32" or "Binary64". GNU COBOL stores "FLOAT-LONG" and "FLOAT-SHORT" data items using either Big- Endian or Little-Endian form, whichever is native to the system. 9. A "USAGE" clause specified at the group item level will apply that "USAGE" to all subordinate data items, except those that themselves have a "USAGE" clause. 10. The only "USAGE" that is allowed in the report section is "USAGE DISPLAY". 3 June 2014 Chapter 5 - DATA DIVISION 196 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 5.9.49. USING (cid:11) (cid:10) USING identifier-1 ~~~~~ USING Clause Syntax (cid:8) (cid:9) ———————————————————————————————————————— This syntax is valid in the following sections: SCREEN This clause logically attaches a screen section data item to another data item defined else- where in the data division. 1. When the screen item whose definition this clause is part of is displayed, the value currently in will be automatically moved into the screen item first. 2. When the screen item whose definition this clause is part of (or its parent) is accepted, the current contents of the screen item will be saved back to at the conclusion of the "ACCEPT". 3. The "FROM" (see [FROM], page 144), "TO" (see [TO], page 183), "USING" and "VALUE" (see [VALUE], page 197) clauses are mutually-exclusive in any screen section data itsm’s definition. Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 197 5.9.50. VALUE (cid:11) (cid:10) VALUE (Condition Names) Clause Syntax } {literal-1 [ THRU|THROUGH literal-2 ]}... { VALUE IS ~~~~ ~~~~~~~ } { ~~~~~ { VALUES ARE } ~~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— (cid:11) (cid:8) (cid:10) VALUE (Other Data Items) Syntax (cid:9) VALUE IS [ ALL ] literal-1 ~~~ ~~~~~ ———————————————————————————————————————— This syntax is valid in the following sections: FILE, WORKING-STORAGE, LOCAL-STORAGE, LINKAGE, REPORT, SCREEN The "VALUE" clause is used to define condition names or to assign values (at compilation time) to data items. 1. The reserved words "ARE" and "IS" are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program. 2. This clause cannot be specified on the same data item as a "FROM" (see [FROM], page 144), "TO" (see [TO], page 183) or "USING" (see [USING], page 196) clause. 3. The following points apply to using the "VALUE" clause in the definition of a condition name: A. The clauses "VALUE IS" and "VALUES ARE" are interchangeable. B. The reserved words "THRU" and "THROUGH" are interchangeable. C. See [88-Level Data Items], page 124, for a discussion of how this format of "VALUE" is used to create condition names. D. See [Condition Names], page 218, for a discussion of how condition names are used. 4. The following points apply to using the "VALUE" clause in the definition of any other data item: A. In this context, "VALUE" specifies an initial compilation-time value that will be assigned to the storage occupied by the data item in the program object code generated by the compiler. 3 June 2014 Chapter 5 - DATA DIVISION 198 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide B. The "VALUE" clause is ignored on "EXTERNAL" (see [EXTERNAL], page 141) data items or on any data items defines as subordinate to an "EXTERNAL" data item. C. This format of the "VALUE" clause may not be used anywhere in the description of an 01 item (or any of it’s subordinate items) serving as an "FD" or "SD" record description. D. If the optional "ALL" clause is used, it may only be used with an alphanumeric literal value; the value will be repeated as needed to completely fill the data item. Here are some examples with and without "ALL" (the symbol b denotes a space): PIC X(5) VALUE "A" PIC X(5) VALUE ALL "A" PIC 9(3) VALUE 1 PIC 9(3) VALUE ALL "1" *> Abbbb *> AAAAA *> 001 *> 111 E. When used in the definition of a screen data item: a. A figurative constant may not be supplied as . b. Any "FROM" (see [FROM], page 144), "TO" (see [TO], page 183) or "USING" (see [USING], page 196) clause in the same data item’s definition will be ignored. c. If there is no picture clause specified, the size of the screen data item will be the length of the value. d. If there is no picture clause and the "ALL" option is specified, the "ALL" option will be ignored. F. Giving a table an initial, compile-time value is one of the trickier aspects of COBOL data definition. There are basically three standard techniques and a fourth that people familiar with other COBOL implementations but new to GNU COBOL may find interesting. So, here are the three standard approaches: a. Don’t bother worrying about it at compile-time. Use the "INITIALIZE" (see [INITIALIZE], page 399) to initialize all data item occurrences in a table (at run-time) to their data-type-specific default values (numerics: 0, alphabetic and alphanumerics: spaces). b. Initialize small tables at compile time by including a "VALUE" clause on the group item that serves as a parent to the table, as follows: 05 SHIRT-SIZES 10 SHIRT-SIZE-TBL 15 SST-SIZE 15 SST-NECK VALUE "S 14M 15L 16XL17". OCCURS 4 TIMES. PIC X(2). PIC 9(2). c. Initialize tables of almost any size at compilation time by utilizing the "REDEFINES" (see [REDEFINES], page 172) clause: 05 SHIRT-SIZE-VALUES. 10 PIC X(4) VALUE "S 14". Chapter 5 - DATA DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 199 10 PIC X(4) 10 PIC X(4) 10 PIC X(4) . 05 SHIRT-SIZES 10 SHIRT-SIZE-TBL 15 SST-SIZE 15 SST-NECK VALUE "M 15". VALUE "L 16". VALUE "XL17" REDEFINES SHIRT-SIZE-VALUES. OCCURS 4 TIMES. PIC X(2). PIC 9(2). Admittedly, this table is much more verbose than the one shown with a group "VALUE". What is good about this initialization technique, however, is that you can have as many "FILLER" and "VALUE" items as you need for a larger table, and those values can be as long as necessary! G. Many COBOL compilers do not allow the use of "VALUE" and "OCCURS" (see [OCCURS], page 158) on the same data item; additionally, they don’t allow a "VALUE" clause on a data item subordinate to an "OCCURS". GNU COBOL, how- ever, has neither of these restrictions! Observe the following example, which illustrates a fourth manner in which tables may be initialized in GNU COBOL: 05 X 10 A 10 B 10 N OCCURS 6 TIMES. PIC X(1) VALUE ’?’. PIC X(1) VALUE ’%’. PIC 9(2) VALUE 10. In this example, all six "A" items will be initialized to "?", all six "B" items will be initialized to "%" and all six "N" items will be initialized to 10. It’s not clear exactly how many times this sort of initialization will be useful, but it’s there if you need it. 5. The "FROM" (see [FROM], page 144), "TO" (see [TO], page 183), "USING" (see [USING], page 196) and "VALUE" clauses are mutually-exclusive in any screen section data itsm’s definition. ———————————————————— End of Chapter 5 — DATA DIVISION 3 June 2014 Chapter 5 - DATA DIVISION GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 201 6. PROCEDURE DIVISION (cid:11) (cid:10) PROCEDURE DIVISION Syntax PROCEDURE DIVISION [ { USING Subprogram-Argument ... ~~~~~~~~~ ~~~~~~~~ } ] } { ~~~~~ { CHAINING Main-Program-Argument...} ~~~~~~~~ [ RETURNING identifier-1 ] . (cid:8) (cid:9) [ DECLARATIVES. ] ~~~~~~~~~~~~ ~~~~~~~~~ [ Event-Handler-Routine... . ] [ END DECLARATIVES. ] ~~~ ~~~~~~~~~~~~ General-Program-Logic [ Nested-Subprogram... ] [ END PROGRAM|FUNCTION name-1 ] ~~~ ~~~~~~~ ~~~~~~~~ ———————————————————————————————————————— The PROCEDURE DIVISION of any GNU COBOL program marks the point where all executable code is written. 3 June 2014 Chapter 6 - PROCEDURE DIVISION 202 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 6.1. PROCEDURE DIVISION USING (cid:11) (cid:10) PROCEDURE DIVISION Subprogram-Argument Syntax (cid:8) (cid:9) [ BY { REFERENCE [ OPTIONAL ] } ] identifier-1 } ~~~~~~~~ { ~~~~~~~~~ } ] } { VALUE [ [ UNSIGNED ] SIZE IS { AUTO } { ~~~~ } { DEFAULT } { ~~~~~~~ { integer-1 } ~~~~~~~~ ~~~~~ ~~~~ ———————————————————————————————————————— The "USING" clause defines the arguments that will be passed to a GNU COBOL program which is serving as a subprogram. 1. The reserved words "BY" and "IS" are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words have no effect upon the program. 2. The "USING" clause should only be used on the procedure division header of subpro- grams (subroutines or user-defined functions). 3. The calling program will pass zero or more data items, known as arguments, to this subprogram — there must be exactly as many data items specified on the USING clause as the maximum number of arguments the subprogram will ever be passed. 4. If a subprogram does not expect any arguments, it should not have a "USING" clause specified on it’s procedure division header. 5. The order in which arguments are defined on the "USING" clause must correspond to the order in which those arguments will be passed to the subprogram by the calling program. 6. The identifiers specified on the "USING" clause must be defined in the linkage section of the subprogram. No storage is actually allocated for those identifiers in the subprogram as the actual storage for them will exist in the calling program. 7. A GNU COBOL subprogram expects that all arguments to it will be one of two things: • The memory address of the actual data item (allocated in the calling program) that is being passed to the subprogram. • A numeric, full-word, binary value (i.e. "USAGE BINARY-LONG" (see [USAGE], page 186)) which is the actual argument being passed to the subprogram. In the case of the former, the "USING" clause on the procedure division header should describe the argument via the "BY REFERENCE" clause — in the latter case, a "BY Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 203 VALUE" specification should be coded. This allows the code generated by the compiler to properly reference the subprogram arguments at run-time. 8. "BY REFERENCE" is the assumed default for the first "USING" argument should no "BY" clause be specified for it. Subsequent arguments will assume the "BY" specification of the argument prior to them should they lack a "BY" clause of their own. 9. Changes made by a subprogram to the value of an argument specified on the "USING" clause will "be visible" to the calling program only if "BY REFERENCE" was explicitly specified or implicitly assumed for the argument on the subprogram’s procedure division header and the argument was passed to the subprogram "BY REFERENCE" by the calling program. See [Subprogram Arguments], page 565, for additional information on the mechanics of how arguments are passed to subprograms. 10. The optional "SIZE" clause allows you to specify the number of bytes a "BY VALUE" argument will occupy, with "SIZE DEFAULT" specifying 4 bytes (this is the default if no "SIZE" clause is used), "SIZE AUTO" specifying the size of the argument in the calling program and "SIZE " specifying a specific byte count. 11. The optional "UNSIGNED" keyword, legal only if "SIZE AUTO" or "SIZE " are coded, will add the "unsigned" attribute to the argument’s specification in the C- language function header code generated for the subprogram. While not of any benefit when the calling program is a GNU COBOL program, this can improve compatibility with a C-language calling program. 12. The "OPTIONAL" keyword, legal only on "BY REFERENCE" arguments, allows calling programs to code "OMITTED" for that corresponding argument when they call this subprogram. See [CALL], page 359. for additional information on this feature. 3 June 2014 Chapter 6 - PROCEDURE DIVISION 204 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 6.2. PROCEDURE DIVISION CHAINING (cid:11) (cid:10) PROCEDURE DIVISION Main-Program-Argument Syntax (cid:8) (cid:9) [ BY REFERENCE ] [ OPTIONAL ] identifier-1 ~~~~~~~~~ ~~~~~~~~ ———————————————————————————————————————— The "CHAINING" term provides one mechanism a programmer may use to retrieve command- line arguments passed to a program at execution time. 1. "PROCEDURE DIVISION CHAINING" may only be coded in a main program (that is, the first program executed when a compiled GNU COBOL compilation unit is executed). It cannot be used in any form of subprogram. 2. The "CHAINING" clause defines arguments that will be passed to a main program from the operating system. The argument identifiers specified on the CHAINING clause will be populated by character strings comprised of the parameters specified to the program on the command line that executed it, as follows: A. When a GNU COBOL program is excecuted from a command-line, the complete command line text will be broken into a series of "tokens", where each token is identified as being a word separated from the others in the command text by at least one space. For example, if the command line was /usr/local/myprog THIS IS A TEST, there will be five tokens identified by the operating system — "/usr/local/myprog", "THIS", "IS", "A" and "TEST". B. Multiple space-delimited tokens may be treated as a single token by enclosing them in quotes. For example, there are only three tokens generated from the command line C:\Pgms\myprog.exe "THIS IS A" TEST — "C:\Pgms\myprog.exe", "THIS IS A" and "TEST". When quote characters are used to create multi-word tokens, the quote characters themselves are stripped from the token’s value. C. Once tokens have been identified, the first (the command) will be discarded; the rest will be stored into the "CHAINING" arguments when the program begins execution, with the 2nd token going to the 1st argument, the 3rd token going to the 2nd argument and so forth. D. If there are more tokens than there are arguments, the excess tokens will be dis- carded. E. If there are fewer tokens than there are arguments, the excess arguments will be initialized as if the "INITIALIZE " (see [INITIALIZE], page 399) statement were executed. F. All identifiers specified on the CHAINING clause should be defined as PIC X, PIC A, group items (which are treated implicitly as PIC X) or as PIC 9 USAGE DISPLAY. The use of USAGE BINARY (or the like) data items as CHAINING Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 205 arguments is not recommended as all command-line tokens will be retained in their original character form as they are moved into the argument data items. G. If an argument identifier is smaller in storage size than the token value to be stored in it, the right-most excess characters of the token value will be truncated as the value is moved in. Any JUSTIFIED RIGHT clause on such an argument identifier will be ignored. H. If an argument is larger in storage size than the token value to be stored in it, the token value will be moved into the argument identifier in a left-justified manner. Un-modified byte positions in the identifier will be space filled, unless the argument identifier is defined as PIC 9 USAGE DISPLAY, in which case unmodified bytes will be filled with "0" characters from the systems native characterset. This behavior when the argument is defined as "PIC 9" may be unacceptable, as an argument defined as "PIC 9(3)" but passed in a value of "1" from the command line will receive a value of "100", not "001". Consider defining "numeric" command line arguments as "PIC X" and then using the "NUMVAL" intrinsic function (see [NUMVAL], page 304) function to determine the proper numeric value. 3 June 2014 Chapter 6 - PROCEDURE DIVISION 206 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 6.3. PROCEDURE DIVISION RETURNING (cid:11) (cid:10) PROCEDURE DIVISION RETURNING Syntax (cid:8) (cid:9) RETURNING identifier-1 ~~~~~~~~~ ———————————————————————————————————————— The RETURNING clause on the PROCEDURE DIVISION header documents that the subprogram in which the clause appears will be returning a numeric value back to the program that called it. 1. The "RETURNING" clause is optional within a subroutine, as not all subroutines return a value to their caller. 2. The "RETURNING" clause is mandatory within a user-defined function, as all such must return a numeric result. 3. The data item should be defined as a USAGE BINARY-LONG data item. 4. Main programs that wish to "pass back" a return code value to the operating system when they exit do not use RETURNING - they do so simply by MOVEing a value to the "RETURN-CODE" special register. 5. This is not the only mechanism that a subprogram may use to pass a value back to it’s caller. Other possibilities are: A. The subprogram may modify any argument that is specified as "BY REFER- ENCE" on it’s PROCEDURE DIVISION header. Whether the calling program can actually "see" any modifications depends upon how the calling program passed the argument to the subprogram. See [CALL], page 359, for more information. B. A data item with the "GLOBAL" (see [GLOBAL], page 146) attribute specified in it’s description in the calling program is automatically visible to and updatable by a subprogram nested with the calling program. See [Independent vs Contained vs Nested Subprograms], page 557, for more information on subprogram nesting. C. A data item defined with the "EXTERNAL" (see [EXTERNAL], page 141) attribute in a subprogram and the calling program (same name in both programs) is auto- matically visible to and updatable by both programs, even if those programs are compiled separately from ona another. Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 207 6.4. PROCEDURE DIVISION Sections and Paragraphs The procedure division is the only one of the COBOL divisions that allows you to create your own sections and paragraphs. These are collectively referred to as ’Procedures’, and the names you create for those sections and paragraphs are called ’Procedure Names’. Procedure names are optional in the procedure division and — when used — are named entirely according to the needs and whims of the programmer. Procedure names may be up to thirty one (31) characters long and may consist of letters, numbers, dashes and underscores. A procedure name may neither begin nor end with a dash (-) or underscore ( ) character. This means that "Main", "0100-Read-Transaction" and "17" are all perfectly valid procedure names. There are three circumstances under which the use of certain GNU COBOL statements or options will require the specification of procedures. These situations are: 1. When "DECLARATIVES" (see [DECLARATIVES], page 208) are specified. 2. When the "ENTRY" statement (see [ENTRY], page 382) is being used. 3. When any procedure division statement that references procedures is used. These statements are: • "ALTER " • "GO TO " • "MERGE ... OUTPUT PROCEDURE " • "PERFORM " • "SORT ... INPUT PROCEDURE " and/or "SORT ... INPUT PROCEDURE " 3 June 2014 Chapter 6 - PROCEDURE DIVISION 208 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 6.5. DECLARATIVES (cid:11) (cid:10) section-name-1 SECTION. DECLARATIVES Syntax (cid:8) (cid:9) ~~~~~~ { ~~~~~~~~~ } { ERROR } ~~~~~ USE { [ GLOBAL ] AFTER STANDARD { EXCEPTION } PROCEDURE ON { INPUT } } { ~~~~~ ~~~ { } } { OUTPUT { } } { ~~~~~~ { } } { I-O { } } { ~~~ { FOR DEBUGGING ON { procedure-name-1 } } { EXTEND { } } } } { ~~~~~~ { { file-name-1 } } { } { } { [ GLOBAL ] BEFORE REPORTING identifier-2 } ~~~~~~ ~~~~~~~~~ { } { } { AFTER EC|{EXCEPTION CONDITION} } { ALL PROCEDURES } } { ~~~ ~~~~~~~~~~ { REFERENCES OF identifier-1 } ~~~~~~~~~ ~~~~~~ ~~ ~~~~~~~~~ ~~~~~~~~~ The "AFTER EXCEPTION CONDITION" and "AFTER EC" clauses are syntactically recognized but are otherwise non-functional. ———————————————————————————————————————— The "DECLARATIVES" area of the procedure division allows the programmer to define a series of "trap" procedures (referred to as declarative procedures) capable of intercepting certain events that may occur at program execution time. The syntax diagram above shows the format of a single such procedure. 1. The reserved words "AFTER", "FOR", "ON", "PROCEDURE" and "STANDARD" are optional and may be included, or not, at the discretion of the programmer. The presence or absence of these words has no effect upon the program. 2. "EC" and "EXCEPTION CONDITION" are interchangeable. 3. The declaratives area may contain any number of declarative procedures, but no two declarative procedures should be coded to trap the same event. 4. The following points apply to the "USE BEFORE REPORTING" clause: A. must be a report group. B. At run-time, the declaratives procedure will be executed prior to the processing of the specified report group’s presentation; within the procedure you may take either of the following actions: Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 209 • You may adjust the value(s) of any items referenced in "SUM" (see [SUM], page 326) or "SOURCE" (see [SOURCE], page 178) clauses in the report group. • You may execute the "SUPPRESS" (see [SUPPRESS], page 471) statement to squelch the presentation of the specified report group altogether. Note that you will be suppressing this one specific instance of that group’s presentation and not all of them. 5. The following points apply to the "USE FOR DEBUGGING" clause: A. This clause allows you to define a declarative procedure that will be invoked whenever. . . • . . . is referenced on any statement. • . . . is executed. • . . . any procedure is executed ("ALL PROCEDURES"). B. A "USE FOR DEBUGGING" declarative procedure will be ignored at compilation time unless "WITH DEBUGGING MODE" is specified in the "SOURCE-COMPUTER" (see [SOURCE-COMPUTER], page 57) paragraph. Neither the compiler’s "-fdebugging-line" switch nor "-debug" switch will activate this feature. C. Any "USE FOR DEBUGGING" declarative procedures will be ignored at execution time unless the "COB_SET_DEBUG" run-time environment variable (see [Run Time Environment Variables], page 522) has been set to a value of "Y", "y" or "1". D. The typical use of a "USE FOR DEBUGGING" declarative procedure is to display the "DEBUG-ITEM" special register, which will be implicitly and automatically created in your program for you if "WITH DEBUGGING MODE" is active. The structure of DEBUG-ITEM will be as follows: 01 DEBUG-ITEM. 05 DEBUG-LINE 05 FILLER 05 DEBUG-NAME 05 FILLER 05 DEBUG-SUB-1 05 FILLER 05 DEBUG-SUB-2 05 FILLER 05 DEBUG-SUB-3 05 FILLER 05 DEBUG-CONTENTS PIC X(6). PIC X(1) VALUE SPACE. PIC X(31). PIC X(1) VALUE SPACE. PIC S9(4) SIGN LEADING SEPARATE. PIC X(1) VALUE SPACE. PIC S9(4) SIGN LEADING SEPARATE. PIC X(1) VALUE SPACE. PIC S9(4) SIGN LEADING SEPARATE. PIC X(1) VALUE SPACE. PIC X(31). where. . . 3 June 2014 Chapter 6 - PROCEDURE DIVISION 210 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide "DEBUG-LINE" . . . is the program line number of the statement that triggered the declaratives procedure. "DEBUG-NAME" . . . is the procedure name or identifier name that triggered the declar- atives procedure. "DEBUG-SUB-1" . . . is the first subscript value (if any) for the reference of the identifier that triggered the declaratives procedure. "DEBUG-SUB-2" . . . is the second subscript value (if any) for the reference of the iden- tifier that triggered the declaratives procedure. "DEBUG-SUB-3" . . . is the third subscript value (if any) for the reference of the identifier that triggered the declaratives procedure. "DEBUG-CONTENTS" . . . is a (brief) statement of the manner in which the procedure that triggered the declaratives procedure was executed or the first 31 char- acters of the value of the identifier whose reference triggered the declar- atives procedure (the value after the statement was executed). 6. The "USE AFTER STANDARD ERROR PROCEDURE" clause defines a declarative procedure invoked any time a failure is encountered with the specified I/O type (or against the specified file(s)). 7. The "GLOBAL" (see [GLOBAL], page 146) option, if used, allows a declarative procedure to be used across the program containing the "USE" statement and any subprograms nested within that program. 8. Declarative procedures may not reference any other procedures defined outside the scope of DECLARATIVES. Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 211 6.6. Table References COBOL uses parenthesis to specify the subscripts used to reference table entries (tables in COBOL are what other programming languages refer to as arrays). For example, observe the following data structure which defines a 4 column by 3 row grid of characters: 01 GRID. 05 GRID-ROW OCCURS 3 TIMES. 10 GRID-COLUMN OCCURS 4 TIMES. 15 GRID-CHARACTER PIC X(1). If the structure contains the following grid of characters: A B C D E F G H I J K L Then "GRID-CHARACTER (2, 3)" references the "G" and "GRID-CHARACTER (3, 2)" ref- erences the "J". Subscripts may be specified as numeric (integer) literals, numeric (integer) data items, data items created with any of the picture-less integer "USAGE" (see [USAGE], page 186) specifications, "USAGE INDEX" data items or arithmetic expressions resulting in a non-zero integer value. In the above examples, a comma is used as a separator character between the two subscript values; semicolons (";") are also valid subscript separator characters, as are spaces! The use of a comma or semicolon separator in such a situation is technically optional, but by convention most COBOL programmers use one or the other. The use of no separator character (other than a space) is not recommended, even though it is syntactically correct, as this practice can lead to programmer-unfriendly code. It isn’t too difficult to read and understand "GRID-CHARACTER(2 3)", but it’s another story entirely when trying to comprehend "GRID-CHARACTER(I + 1 J / 3)" (instead of "GRID-CHARACTER(I + 1, J / 3)"). The compiler accepts it, but too much of this would make my head hurt. 3 June 2014 Chapter 6 - PROCEDURE DIVISION 212 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 6.7. Qualification of Data Names COBOL allows data names to be duplicated within a program, provided references to those data names may be made in such a manner as to make those references unique through a process known as qualification. To see qualification at work, observe the following segments of two data records defined in a COBOL program: 01 EMPLOYEE. 05 MAILING-ADDRESS. 01 CUSTOMER. 05 MAILING-ADDRESS. 10 STREET 10 CITY 10 STATE 10 ZIP-CODE. PIC X(35). PIC X(15). PIC X(2). 10 STREET 10 CITY 10 STATE 10 ZIP-CODE. PIC X(35). PIC X(15). PIC X(2). 15 ZIP-CODE-5 PIC 9(5). PIC X(4). 15 FILLER 15 ZIP-CODE-5 PIC 9(5). PIC X(4). 15 FILLER let’s deal with the problem of setting the CITY portion of an EMPLOYEEs Now, MAILING-ADDRESS to "Philadelphia". Clearly, "MOVE ’Philadelphia’ TO CITY" cannot work because the compiler will be unable to determine which of the two CITY fields you are referring to. In an attempt to correct the problem, we could qualify the reference to CITY as "MOVE ’Philadelphia’ TO CITY OF MAILING-ADDRESS". Unfortunately that too is insufficient because it still insufficiently specifies which CITY is being referenced. To truly identify which specific CITY you want, you’d have to code "MOVE ’Philadelphia’ TO CITY OF MAILING-ADDRESS OF EMPLOYEE". Now there can be no confusion as to which CITY is being changed. Fortunately, you don’t need to be quite so specific; COBOL allows intermediate and unnecessary qualification levels to be omitted. This allows "MOVE ’Philadelphia’ TO CITY OF EMPLOYEE" to do the job nicely. If you need to qualify a reference to a table, do so by coding something like " OF ( subscript(s) )". The reserved word "IN" may be used in lieu of "OF". Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 213 6.8. Reference Modifiers (cid:11) (cid:10) Reference Modifier (Format 1) Syntax (cid:8) (cid:9) identifier-1 [ OF|IN identifier-2 ] [ (subscript...) ] (start:[ length ]) ~~ ~~ ———————————————————————————————————————— (cid:11) (cid:8) (cid:10) Reference Modifier (Format 2) Syntax (cid:9) intrinsic-function-reference (start:[ length ]) ———————————————————————————————————————— The COBOL ’85 standard introduced the concept of a reference modifier to facilitate refer- ences to only a portion of a data item; GNU COBOL fully supports reference modification. The value indicates the starting character position being referenced (character posi- tion values start with 1, not 0 as is the case in some programming languages) and specifies how many characters are wanted. If no is specified, a value equivalent to the remaining character positions from to the end of or to the end of the value returned by the function will be assumed. Both and may be specified as integer numeric literals, integer numeric data items or arithmetic expressions with an integer value. Here are a few examples: "CUSTOMER-LAST-NAME (1:3)" References the first three characters of CUSTOMER-LAST-NAME. "CUSTOMER-LAST-NAME (4:)" References all character positions of CUSTOMER-LAST-NAME from the fourth onward. "FUNCTION CURRENT-DATE (5:2)" References the current month as a 2-digit number in character form. See [CURRENT-DATE], page 257, for more information. "Hex-Digits (Nibble + 1:1)" Assuming that "Nibble" is a numeric data item with a value in the range 0-15, and Hex-Digits is a "PIC X(16)" item with a value of "0123456789ABCDEF", this converts that numeric value to a hexadecimal digit. 3 June 2014 Chapter 6 - PROCEDURE DIVISION 214 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide "Table-Entry (6) (7:5)" References characters 7 through 11 (5 characters in total) in the 6th occurrence of Table-Entry. Reference modification may be used anywhere an identifier is legal, including serving as the receiving field of statements like "MOVE" (see [MOVE], page 414), "STRING" (see [STRING], page 463) and "ACCEPT" (see [ACCEPT], page 338), to name a few. Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 215 6.9. Arithmetic Expressions (cid:11) (cid:10) Arithmetic-Expression Syntax Unary-Expression-1 { **|^ } Unary-Expression-2 { *|/ } { +|- } (cid:8) (cid:9) ———————————————————————————————————————— (cid:11) (cid:8) (cid:10) Unary-Expression Syntax (cid:9) { [ +|- ] { ( Arithmetic-Expression-1 ) { { { { Arithmetic-Expression-2 { [ LENGTH OF ] { identifier-1 { { } } } } } { literal-1 } } } { Function-Reference } } } } ~~~~~~ ~~ ———————————————————————————————————————— Arithmetic expressions are formed using four categories of operations — exponentiation, multiplication & division, addition & subtraction, and sign specification. In complex expressions composed of multiple operators and operands, a precedence of op- eration applies whereby those operations having a higher precedence are computed first before operations with a lower precedence. As is the case in almost any other programming language, the programmer is always free to use pairs of parenthesis to enclose sub-expressions of complex expressions that are to be evaluated before other sub-expressions rather than let operator precedence dictate the sequence of evaluation. In highest to lowest order of precedence, here is a discussion of each category of operation: Level 1 (Highest) — Unary Sign Specification ("+" and "-" with a single argument) The unary "minus" (-) operator returns the arithmetic negation of its single argument, effectively returning as its value the product of its argument and -1. The unary "plus" (+) operator returns the value of its single argument, effec- tively returning as its value the product of its argument and +1. Level 2 — Exponentiation ("**" or "^") The value of the left argument is raised to the power indicated by the right ar- gument. Non-integer powers are allowed. The "^" and "**" operators are both supported to provide compatibility with programs written for other COBOL implementations. 3 June 2014 Chapter 6 - PROCEDURE DIVISION 216 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide Level 3 — Multiplication ("*") and division ("/") The "*" operator computes the product of the left and right arguments while the "/" operator computes the value of the left argument divided by the value of the right argument. If the right argument has a value of zero, expression evaluation will be prematurely terminated before a value is generated. This may cause program failure at run-time. A sequence of multiple 3rd-level operations ("A * B / C", for example) will evaluate in strict left-to-right sequence if no parenthesis are used to control the order of evaluation. Level 4 — Addition ("+") or subtraction ("+") The "+" operator calculates the sum of the left and right arguments while the "-" operator computes the value of the right argument subtracted from that of the left argument. A sequence of multiple 4th-level operations ("A - B + C", for example) will evaluate in strict left-to-right sequence if no parenthesis are used to control the order of evaluation. The syntactical rules of COBOL, allowing a dash (-) character in data item names, can lead to some ambiguity. PIC 9 VALUE 5. PIC 9 VALUE 2. PIC 9 VALUE 7. PIC 9 VALUE 0. 01 C 01 D 01 C-D 01 I ... COMPUTE I=C-D+1 The "COMPUTE" (see [COMPUTE], page 366) statement will evaluate the arithmetic expres- sion "C-D+1" and then save that result in "I". What value will be stored in "I"? The number 4, which is the result of subtracting the value of "D" (2) from the value of "C" (5) and then adding 1? Or, will it be the number 8, which is the value of adding 1 to the value of data item "C-D" (7)? The right answer is 8 — the value of data item "C-D" plus 1! Hopefully, that was the intended result. The GNU COBOL compiler actually went through the following decision-making logic when generating code for the "COMPUTE" Statement: 1. Is there a data item named "C-D" defined? If so, use its value for the character sequence "C-D". Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 217 2. If there is no "C-D" data item, then are there "C" and "D" data items? If not, the "COMPUTE" statement is in error. If there are, however, then code will be generated to subtract the value of "D" from "C" and add 1 to the result. Had there been at least one space to the left and/or the right of the "-", there would have been no ambiguity — the compiler would have been forced to use the individual "C" and "D" data items. To avoid any possible ambiguity, as well as to improve program readability, it’s considered good COBOL programming practice to always code at least one space to both the left and right of every operator in arithmetic expressions as well as the "=" sign on a COMPUTE. Here are some examples of how the precedence of operations affects the results of arithmetic expressions (all examples use numeric literals, to simplify the discussion). Expression 3 * 4 + 1 4 * 2 ^ 3 - 10 (4 * 2) ^ 3 - 10 Result Notes 13 22 502 * has precedence over + 2^3 is 8 (^ has precedence over *), times 4 is 32, minus 10 is 22. Parenthesis provide for a recursive application of the arithmetic expression rules, effectively allowing you to alter the precedence of operations. 4 times 2 is 8 (the use of parenthesis "trumps" the exponention operator, so the multiplication happens first); 8 ^ 3 is 512, minus 10 is 502. 5 / 2.5 + 7 * 2 - 1.15 15.35 Integer and non-integer operands may be freely intermixed Of course, arithmetic expression operands may be numeric data items (any USAGE except POINTER or PROGRAM POINTER) as well as numeric literals. 3 June 2014 Chapter 6 - PROCEDURE DIVISION 218 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 6.10. Conditional Expressions Conditional expressions are expressions which identify the circumstances under which a program may take an action or cease taking an action. As such, conditional expressions produce a value of TRUE or FALSE. There are seven types of conditional expressions, as discussed in the following sections. 6.10.1. Condition Names These are the simplest of all conditions. Observe the following code: 05 SHIRT-SIZE 88 TINY 88 XS 88 S 88 M 88 L 88 XL 88 XXL 88 XXXL 88 VERY-LARGE PIC 99V9. VALUE 0 THRU 12.5 VALUE 13 THRU 13.5. VALUE 14, 14.5. VALUE 15, 15.5. VALUE 16, 16.5. VALUE 17, 17.5. VALUE 18, 18.5. VALUE 19, 19.5. VALUE 20 THRU 99.9. The condition names "TINY", "XS", "S", "M", "L", "XL", "XXL", "XXXL" and "VERY-LARGE" will have TRUE or FALSE values based upon the values within their parent data item (SHIRT-SIZE). A program wanting to test whether or not the current "SHIRT-SIZE" value can be classified as "XL" could have that decision coded as a combined condition (the most complex type of conditional expression), as either: IF SHIRT-SIZE = 17 OR SHIRT-SIZE = 17.5 - or - IF SHIRT-SIZE = 17 OR 17.5 Or it could simply utilize the condition name XL as follows: IF XL Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 219 6.10.2. Class Conditions (cid:11) (cid:10) Class-Condition Syntax ~~~ } identifier-1 IS [ NOT ] { NUMERIC } { ~~~~~~~ } { ALPHABETIC { ~~~~~~~~~~ } { ALPHABETIC-LOWER } { ~~~~~~~~~~~~~~~~ } { ALPHABETIC-UPPER } { ~~~~~~~~~~~~~~~~ } } { OMITTED } { ~~~~~~~ } { class-name-1 (cid:8) (cid:9) ———————————————————————————————————————— Class conditions evaluate the type of data that is currently stored in a data item. 1. The "NUMERIC" class test considers only the characters "0", "1", , "9" to be numeric; only a data item containing nothing but digits will pass a "NUMERIC" class test. Spaces, decimal points, commas, currency signs, plus signs, minus signs and any other characters except the digit characters will all fail "NUMERIC" class tests. . . . 2. The "ALPHABETIC" class test considers only upper-case letters, lower-case letters and spaces to be alphabetic in nature. 3. The "ALPHABETIC-LOWER" and "ALPHABETIC-UPPER" class conditions consider only spaces and the respective type of letters to be acceptable in order to pass such a class test. 4. The "NOT" option reverses the TRUE/FALSE value of the condition. 5. Note that what constitutes a "letter" (or upper/lower case too, for that manner) may be influenced through the use of "CHARACTER CLASSIFICATION" specifications in the "OBJECT-COMPUTER" (see [OBJECT-COMPUTER], page 58) paragraph. 6. Only data items whose "USAGE" (see [USAGE], page 186) is either explicitly or implic- itly defined as "DISPLAY" may be used in "NUMERIC" or any of the "ALPHABETIC" class conditions. 7. Some COBOL implementations disallow the use of group items or "PIC A" items with "NUMERIC" class conditions and the use of "PIC 9" items with "ALPHABETIC" class conditions. GNU COBOL has no such restrictions. 8. The "OMITTED" class condition is used when it is necessary for a subprogram to deter- mine whether or not a particular argument was passed to it. In such class conditions, must be a linkage section item defined on the "USING" clause of the sub- 3 June 2014 Chapter 6 - PROCEDURE DIVISION 220 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide programs "PROCEDURE DIVISION" header. See [PROCEDURE DIVISION USING], page 202, for additional information. The option allows you to test for a user-defined class. Here’s an example. First, assume the following "SPECIAL-NAMES" (see [SPECIAL-NAMES], page 62) definition of the user-defined class "Hexadecimal": SPECIAL-NAMES. CLASS Hexadecimal IS ’0’ THRU ’9’, ’A’ THRU ’F’, ’a’ THRU ’f’. Now observe the following code, which will execute the "150-Process-Hex-Value" proce- dure if "Entered-Value" contains nothing but valid hexadecimal digits: IF Entered-Value IS Hexadecimal PERFORM 150-Process-Hex-Value END-IF Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 221 6.10.3. Sign Conditions (cid:11) (cid:10) Sign-Condition Syntax ~~~ identifier-1 IS [ NOT ] { POSITIVE } { ~~~~~~~~ } { NEGATIVE } { ~~~~~~~~ } { ZERO } ~~~~ (cid:8) (cid:9) ———————————————————————————————————————— Sign conditions evaluate the numeric state of a data item defined with a "PICTURE" (see [PICTURE], page 162) and/or "USAGE" (see [USAGE], page 186) that supports numeric values. 1. A "POSITIVE" or "NEGATIVE" class condition will be TRUE only if the value of is strictly greater than or less than zero, respectively. 2. A "ZERO" class condition can be passed only if the value of is exactly zero. 3. The "NOT" option reverses the TRUE/FALSE value of the condition. 3 June 2014 Chapter 6 - PROCEDURE DIVISION 222 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 6.10.4. Switch-Status Conditions In the "SPECIAL-NAMES" (see [SPECIAL-NAMES], page 62) paragraph, an external switch name can be associated with one or more condition names. These condition names may then be used to test the ON/OFF status of the external switch. Here are the relevant sections of code in a program named "testprog", which is designed to simply announce if SWITCH-1 is on: ... ENVIRONMENT DIVISION. SPECIAL-NAMES. SWITCH-1 ON STATUS IS Switch-1-Is-ON. ... PROCEDURE DIVISION. ... IF Switch-1-Is-ON DISPLAY "Switch 1 Is On" END-IF ... the following are two different command window sessions — the left on a Unix/Cygwin/OSX system and the right on a windows system — that will set the switch on and then execute the "testprog" program. Notice how the message indicating that the program detected the switch was set is displayed in both examples: $ COB_SWITCH_1=ON $ export COB_SWITCH_1 $ ./testprog Switch 1 Is On $ C:>SET COB_SWITCH_1=ON C:>testprog Switch 1 Is On C:> Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 223 6.10.5. Relation Conditions (cid:11) (cid:10) Relation-Condition Syntax (cid:8) (cid:9) } IS [ NOT ] RelOp { identifier-2 { identifier-1 } { literal-1 { arithmetic-expression-1 } } { index-name-1 } } { literal-2 { arithmetic-expression-2 } } { index-name-2 ~~~ ———————————————————————————————————————— (cid:11) (cid:8) (cid:10) RelOp Syntax (cid:9) } { EQUAL TO } { ~~~~~ } { EQUALS } { ~~~~~~ } { GREATER THAN { ~~~~~~~ } { GREATER THAN OR EQUAL TO } } { ~~~~~~~ } { LESS THAN } { ~~~~ } { LESS THAN OR EQUAL TO } { ~~~~ } { = } { > } { >= } { < } { <= ~~ ~~~~~ ~~ ~~~~~ ———————————————————————————————————————— These conditions evaluate how two different values "relate" to each other. 1. When comparing one numeric value to another, the "USAGE" (see [USAGE], page 186) and number of significant digits in either value are irrelevant as the comparison is performed using the actual algebraic values. 2. When comparing strings, the comparison is made based upon the program’s collating sequence. When the two string arguments are of unequal length, the shorter is assumed to be padded (on the right) with a sufficient number of spaces as to make the two strings of equal length. String comparisons take place on a corresponding character- by-character basis, left to right, until the TRUE/FALSE value for the relation test can be established. Characters are compared according to their relative position in the program’s "COLLATING SEQUENCE" (as defined in "SPECIAL-NAMES" (see [SPECIAL- 3 June 2014 Chapter 6 - PROCEDURE DIVISION 224 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide NAMES], page 62)), not according to the bit-pattern values the characters have in storage. 3. By default, the program’s "COLLATING SEQUENCE" will, however, be based entirely on the bit-pattern values of the various characters. 4. There is no functional difference between using the wordy version ("IS EQUAL TO", "IS LESS THAN", . . . ) versus the symbolic version ("=", "<", . . . ) of the actual relation operators. Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 225 6.10.6. Combined Conditions (cid:11) (cid:10) Combined Condition Syntax [ ( ] Condition-1 [ ) ] { AND } [ ( ] Condition-2 [ ) ] { ~~~ } { OR } { ~~ } (cid:8) (cid:9) ———————————————————————————————————————— A combined condition is one that computes a TRUE/FALSE value from the TRUE/FALSE values of two other conditions (which could themselves be combined conditions). 1. If either condition has a value of TRUE, the result of "OR"ing the two together will result in a value of TRUE. "OR"ing two FALSE conditions will result in a value of FALSE. 2. In order for "AND" to yield a value of TRUE, both conditions must have a value of TRUE. In all other circumstances, "AND" produces a FALSE value. 3. When chaining multiple, similar conditions (OR/AND), and left or right arguments have common subjects, abbreviate the program code. For example: together with the same operator it is possible to IF ACCOUNT-STATUS = 1 OR ACCOUNT-STATUS = 2 OR ACCOUNT-STATUS = 7 Could be abbreviated as: IF ACCOUNT-STATUS = 1 OR 2 OR 7 4. Just as multiplication takes precedence over addition in arithmetic expressions, so does "AND" take precedence over "OR" in combined conditions. Use parenthesis to change this precedence, if necessary. For example: "FALSE AND FALSE OR TRUE AND TRUE" Evaluates to TRUE "(FALSE AND FALSE) OR (TRUE AND TRUE)" Evaluates to TRUE (since AND has precedence over OR) - this is identical to the previous example "(FALSE AND (FALSE OR TRUE)) AND TRUE" Evaluates to FALSE 3 June 2014 Chapter 6 - PROCEDURE DIVISION 226 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 6.10.7. Negated Conditions (cid:11) (cid:10) NOT Condition-1 ~~~ Negated Condition Syntax (cid:8) (cid:9) ———————————————————————————————————————— A condition may be negated by prefixing it with the "NOT" operator. 1. The "NOT" operator has the highest precedence of all logical operators, just as a unary minus sign (which "negates" a numeric value) is the highest precedence arithmetic operator. 2. Parenthesis must be used to explicitly signify the sequence in which conditions are evaluated and processed if the default precedence isn’t desired. For example: "NOT TRUE AND FALSE AND NOT FALSE" Evaluates to FALSE AND FALSE AND TRUE which evaluates to FALSE "NOT (TRUE AND FALSE AND NOT FALSE)" Evaluates to NOT (FALSE) which evaluates to TRUE "NOT TRUE AND (FALSE AND NOT FALSE)" Evaluates to FALSE AND (FALSE AND TRUE) which evaluates to FALSE Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 227 6.11. Use of Periods All COBOL implementations distinguish between sentences and statements in the procedure division. A ’Statement’ is a single executable COBOL instruction. For example, these are all statements: MOVE SPACES TO Employee-Address ADD 1 TO Record-Counter DISPLAY "Record-Counter=" Record-Counter Some COBOL statements have a "scope of applicability" associated with them where one or more other statements can be considered to be part of or related to the statement in question. An example of such a situation might be the following, where the interest on a loan is being calculated and displayed — 4% interest if the loan balance is under $10000 and 4.5% otherwise (WARNING – the following code has an error!): IF Loan-Balance < 10000 MULTIPLY Loan-Balance BY 0.04 GIVING Interest ELSE MULTIPLY Loan-Balance BY 0.045 GIVING Interest DISPLAY "Interest Amount = " Interest In this example, the IF statement actually has a scope that can include two sets of associated statements – one set to be executed when the "IF" (see [IF], page 397) condition is TRUE and another if it is FALSE. Unfortunately, there’s a problem with the above. A human being looking at that code would probably infer that the "DISPLAY" (see [DISPLAY], page 370) statement, because of its lack of indentation, is to be executed regardless of the TRUE/FALSE value of the "IF" condition. Unfortunately, the GNU COBOL compiler (or any other COBOL compiler for that matter) won’t see it that way because it really couldn’t care less what sort of indentation, if any, is used. In fact, any COBOL compiler would be just as happy to see the code written like this: IF Loan-Balance < 10000 MULTIPLY Loan-balance BY 0.04 GIVING Interest ELSE MULTIPLY Loan-Balance BY 0.045 GIVING Interest DISPLAY "Interest Amount = " Interest So how then do we inform the compiler that the "DISPLAY" statement is outside the scope of the "IF"? That’s where sentences come in. A COBOL ’Sentence’ is defined as any arbitrarily long sequence of statements, followed by a period (.) character. The period character is what terminates the scope of a set of statements. Therefore, our example should have been coded like this: IF Loan-Balance < 10000 3 June 2014 Chapter 6 - PROCEDURE DIVISION 228 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide MULTIPLY Loan-Balance BY 0.04 GIVING Interest ELSE MULTIPLY Loan-Balance BY 0.045 GIVING Interest. DISPLAY "Interest Amount = " Interest See the period at the end of the second "MULTIPLY" (see [MULTIPLY], page 416)? That is what terminates the scope of the "IF", thus making the "DISPLAY" statement’s execution completely independent of the TRUE/FALSE status of the "IF". Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 229 6.12. Use of VERB/END-VERB Constructs Prior to the 1985 COBOL standard, using a period character was the only way to signal the end of a statement’s scope. Unfortunately, this caused some problems. Take a look at this code: IF A = 1 IF B = 1 DISPLAY "A & B = 1" ELSE *> This ELSE has a problem! IF B = 1 DISPLAY "A NOT = 1 BUT B = 1" ELSE DISPLAY "NEITHER A NOR B = 1". The problem with this code is that indentation — so critical to improving the human- readability of a program — can provide an erroneous view of the logical flow. An "ELSE" is always associated with the most-recently encountered "IF"; this means the emphasized "ELSE" will be associated with the "IF B = 1" statement, not the "IF A = 1" statement as the indentation would appear to imply. This sort of problem led to a band-aid solution — the "NEXT SENTENCE" clause — being added to the COBOL language. IF A = 1 IF B = 1 DISPLAY "A & B = 1" ELSE NEXT SENTENCE ELSE IF B = 1 DISPLAY "A NOT = 1 BUT B = 1" ELSE DISPLAY "NEITHER A NOR B = 1". The "NEXT SENTENCE" clause informs the compiler that if the "B = 1" condition is false, control should fall into the first statement that follows the next period. With the 1985 standard for COBOL, a much more elegant solution was introduced. Any COBOL ’Verb’ (the first reserved word of a statement) that needed such a thing was allowed to use an "END-verb" construct to end it’s scope without disrupting the scope of any other statement it might have been in. Any COBOL 85 compiler would have allowed the following solution to our problem: IF A = 1 IF B = 1 DISPLAY "A & B = 1" 3 June 2014 Chapter 6 - PROCEDURE DIVISION 230 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide END-IF ELSE IF B = 1 DISPLAY "A NOT = 1 BUT B = 1" ELSE DISPLAY "NEITHER A NOR B = 1". This new facility made the period almost obsolete, as our program segment would probably be coded like this today: IF A = 1 IF B = 1 DISPLAY "A & B = 1" END-IF ELSE IF B = 1 DISPLAY "A NOT = 1 BUT B = 1" ELSE DISPLAY "NEITHER A NOR B = 1" END-IF END-IF COBOL (GNU COBOL included) still requires that each procedure division paragraph contain at least one sentence if there is any executable code in that paragraph, but a popular coding style is now to simply code a single period right before the end of each paragraph. The standard for the COBOL language shows the various "END-verb" clauses are optional because using a period as a scope-terminator remains legal. If you will be porting existing code over to GNU COBOL, you’ll find it an accommodating facility capable of conforming to whatever language and coding standards that code is likely to use. If you are creating new GNU COBOL programs, however, I would strongly counsel you to use the "END-verb" structures in those programs. Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 231 6.13. Concurrent Access to Files The manipulation of data files is one of the COBOL language’s great strengths. There are features built into COBOL to deal with the possibility that multiple programs may be attempting to access the same file concurrently. Multiple program concurrent access is dealt with in two ways — file sharing and record locking. Not all GNU COBOL implementations support file sharing and record-locking options. Whether they do or not depends upon the operating system they were built for and the build options that were used when the specific GNU COBOL implementation was generated. 6.13.1. File Sharing GNU COBOL controls concurrent-file access at the highest level through the concept of file sharing, enforced when a program attempts to open a file. This is accomplished via a UNIX operating-system routine called "fcntl()". That module is not currently supported by Windows and is not present in the MinGW Unix-emulation package. GNU COBOL builds created using a MinGW environment will be incapable of supporting file-sharing controls — files will always be shared in such environments. A GNU COBOL build created using the Cygwin environment on Windows would have access to "fcntl()" and therefore will support file sharing. Of course, actual Unix builds of GNU COBOL, as well as OSX builds, should have no issues because "fcntl()" should be available. Any limitations imposed on a successful "OPEN" (see [OPEN], page 420) will remain in place until your program either issues a "CLOSE" (see [CLOSE], page 364) against the file or the program terminates. File sharing is controlled through the use of a "SHARING" clause: SHARING WITH { ALL OTHER } } ~~~~~~~ { ~~~ { NO OTHER } { ~~ } { READ ONLY } ~~~~ ~~~~ This clause may be used either in the file’s "SELECT" statement (see [SELECT], page 73), on the "OPEN" statement (see [OPEN], page 420) which initiates your program’s use of the file, or both. If a "SHARING" option is specified in both places, the specifications made on the "OPEN" statement will take precedence over those from the "SELECT" statement. Here are the meanings of the three options: "ALL OTHER" When your program opens a file with this sharing option in effect, no restric- tions will be placed on other programs attempting to "OPEN" the file after your program did. This is the default sharing mode. 3 June 2014 Chapter 6 - PROCEDURE DIVISION 232 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide "NO OTHER" When your program opens a file with this sharing option in effect, your program announces that it is unwilling to allow any other program to have any access to the file as long as you are using that file; "OPEN" attempts made in other programs will fail with a file status of 37 ("PERMISSION DENIED") until such time as you "CLOSE" (see [CLOSE], page 364) the file. "READ ONLY" Opening a file with this sharing option indicates you are willing to allow other programs to "OPEN" the file for input while you have it open. If they attempt any other "OPEN", theirs will fail with a file status of 37. Of course, your program may fail if someone else got to the file first and opened it with a sharing option that imposed file-sharing limitations. If the "SELECT" of a file is coded with a "FILE STATUS" clause, "OPEN" failures — including those induced by sharing failures — will be detectable by the program and a graceful recovery (or at least a graceful termination) will be possible. If no such clause was coded, however, a runtime message will be issued and the program will be terminated. Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 233 6.13.2. Record Locking Record-locking is supported by advanced file-management software built-in to the GNU COBOL implementation you are using. This software provides a single point-of-control for access to files — usually "ORGANIZATION INDEXED" (see [ORGANIZATION INDEXED], page 84) files. One such runtime package capable of doing this is the Berkely Database (BDB) package — a package frequently used in GNU COBOL builds to support indexed files. The various I/O statements your program can execute are capable of imposing limitations on access by other concurrently-executing programs to the file record they just accessed. These limitations are syntactically imposed by placing a lock on the record using a "LOCK" clause. Other records in the file remain available, assuming that file-sharing limitations imposed at the time the file was opened didn’t prevent access to the entire file. 1. If the GNU COBOL build you are using was configured to use the Berkely Data- base (BDB) package for indexed file I/O, record locking will be available by using the "DB_HOME" run-time environment variable (see [Run Time Environment Variables], page 522). 2. If the "SELECT" (see [SELECT], page 73) statement or file "OPEN" (see [OPEN], page 420) specifies "SHARING WITH NO OTHER", record locking will be disabled. 3. If the file’s "SELECT" contains a "LOCK MODE IS AUTOMATIC" clause, every time a record is read from the file, that record is automatically locked. Other programs may access other records within the file, but not a locked record. 4. If the file’s "SELECT" contains a "LOCK MODE IS MANUAL" clause, locks are placed on records only when a "READ" statement executed against the file includes a "LOCK" clause (this clause will be discussed shortly). 5. If the "LOCK ON" clause is specified in the file’s "SELECT", locks (either automatically or manually acquired) will continue to accumulate as more and more records are read, until they are explicitly released. This is referred to as ’multiple record locking’. Locks acquired vie multiple record locking remain in-effect until the program holding the lock. . . • . . . terminates, or . . . • . . . executes a "CLOSE" statement (see [CLOSE], page 364) against the file, or . . . • . . . executes an "UNLOCK" statement (see [UNLOCK], page 474) against the file, or . . . • . . . executes a "COMMIT" statement (see [COMMIT], page 365) or . . . • . . . executes a "ROLLBACK" statement (see [ROLLBACK], page 439). 6. If the "LOCK ON" clause is not specified, then the next I/O statement your program executes, except for "START" (see [START], page 459), will release the lock. This is referred to as ’single record locking’. 3 June 2014 Chapter 6 - PROCEDURE DIVISION 234 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 7. A "LOCK" clause, which may be coded on a "READ" (see [READ], page 428), "REWRITE" (see [REWRITE], page 437) or "WRITE" statement (see [WRITE], page 479) looks like this: } { IGNORING LOCK { ~~~~~~~~ ~~~~ } { WITH [ NO ] LOCK } ~~~~ } ~~ { } { WITH KEPT LOCK { } ~~~~ ~~~~ { WITH IGNORE LOCK } ~~~~~~ ~~~~ } { { WITH WAIT } ~~~~ The "WITH [ NO ] LOCK" option is the only one available to "REWRITE" or "WRITE" statements. The meanings of the various record locking options are as follows: "IGNORING LOCK" "WITH IGNORE LOCK" These options (which are synonymous) inform GNU COBOL that any locks held by other programs should be ignored. "WITH LOCK" Access to the record by other programs will be denied. "WITH NO LOCK" The record will not be locked. This is the default locking option in effect for all statements. "WITH KEPT LOCK" When single record locking is in-effect, as a new record is accessed, locks held for previous records are released. By using this option, not only is the newly-accessed record locked (as WITH LOCK would do), but prior record locks will be retained as well. A subsequent "READ" without the "KEPT LOCK" option will release all "kept" locks, as will the "UNLOCK" statement. "WITH WAIT" This option informs GNU COBOL that the program is willing to wait for a lock held (by another program) on the record being read to be released. Without this option, an attempt to read a locked record will be immediately aborted and a file status of 47 will be returned. With this option, the program will wait for a pre-configured time for the lock to be released. If the lock is released within the preconfigured wait Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 235 time, the read will be successful. If the pre-configured wait time expires before the lock is released, the read attempt will be aborted and a 47 file status will be issued. 6.14. Common Clauses on Executable Statements 6.14.1. AT END + NOT AT END (cid:11) (cid:10) AT END Syntax [ AT END imperative-statement-1 ] ~~~ [ NOT AT END imperative-statement-2 ] ~~~ ~~~ (cid:8) (cid:9) ———————————————————————————————————————— "AT END" clauses may be specified on "READ" (see [READ], page 428), "RETURN" (see [RETURN], page 436), "SEARCH" (see [SEARCH], page 440) and "SEARCH ALL" (see [SEARCH ALL], page 442) statements. 1. The following points pertain to the use of these clauses on "READ" (see [READ], page 428) and "RETURN" (see [RETURN], page 436) statements: A. The "AT END" clause will — if present — cause (see [Imperative Statement], page 593) to be executed if the statement fails due to a file status of 10 (end-of-file). See [File Status Codes], page 76, for a list of possible File Status codes. An "AT END" clause will not detect other non-zero file-status values. Use a "DECLARATIVES" (see [DECLARATIVES], page 208) routine or an explicitly- declared file status field tested after the "READ" or "RETURN" to detect error con- ditions other than end-of-file. B. A "NOT AT END" clause will cause to be executed if the "READ" or "RETURN" attempt is successful. 2. The following points pertain to the use of these clauses on "SEARCH" (see [SEARCH], page 440) and "SEARCH ALL" (see [SEARCH ALL], page 442) statements: A. An "AT END" clause detects and handles the case where either form of table search has failed to locate an entry that satisfies the search conditions being used. B. The "NOT AT END" clause is not allowed on either form of table search. 3 June 2014 Chapter 6 - PROCEDURE DIVISION 236 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 6.14.2. CORRESPONDING Three GNU COBOL statements — "ADD" (see [ADD CORRESPONDING], page 354), "MOVE" (see [MOVE CORRESPONDING], page 415) and "SUBTRACT" (see [SUBTRACT CORRESPONDING], page 469) support the use of a "CORRESPONDING" option: ADD CORRESPONDING group-item-1 TO group-item-2 MOVE CORRESPONDING group-item-1 TO group-item-2 SUBTRACT CORRESPONDING group-item-1 FROM group-item-2 This option allows one or more data items within one group item ( — the first named on the statement) to be paired with correspondingly-named (hence the name) in a second group item ( — the second named on the statement). The contents of will remain unaffected by the statement while one or more data items within will be changed. In order for , defined subordinate to group item to be a "corresponding" match to which is subordinate to , each of the following must be true: 1. Both and must have the same name, and that name may not explicitly or implicitly be "FILLER". 2. Both and . . . A. B. . . . must exist at the same relative structural "depth" of definition within and , respectively . . . and all "parent" data items defined within each group item must have identical (but non-"FILLER") names. 3. When used with a "MOVE" verb. . . A. . . . one of or (but not both) is allowed to be a group item B. . . . and it must be valid to move TO . 4. When used with "ADD" or "SUBTRACT" verbs, both and must be numeric, elementary, unedited items. 5. Neither nor may be a "REDEFINES" (see [REDEFINES], page 172) or "RENAMES" (see [RENAMES], page 173) of another data item. 6. Neither nor may have an "OCCURS" (see [OCCURS], page 158) clause, although either may contain subordinate data items that do have an "OCCURS" clause (assuming rule 3a applies) Observe the definitions of data items "Q" and "Y". . . 01 Q. 03 X. 05 A 01 Y. 02 A 02 G1. PIC 9(1). PIC X(1). Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 237 05 G1. 10 G2. 15 B PIC X(1). 05 C. 10 FILLER PIC X(1). 03 G2. 04 B 02 C 02 G3. 03 G5. 04 D 03 G6 05 G3. 10 G4. 15 D 05 E 05 F 05 G. 10 G6 05 H 05 I 05 J. 10 K. PIC X(1). PIC X(1). REDEFINES V1 PIC X(1). 02 E 02 F 02 G 02 H OCCURS 4 TIMES PIC X(1). PIC X(4). PIC 9(1). 66 I 02 J. 03 K. 04 L. 05 M. PIC X(1). PIC X(1). PIC X(1). PIC X(1). PIC 9(1). PIC X(1). PIC X(4). OCCURS 4 TIMES PIC X(1). RENAMES E. 15 M PIC X(1). The following are the valid CORRESPONDING matches, assuming the statement "MOVE CORRESPONDING X TO Y" is being executed (there are no valid corresponding matches for "ADD CORRESPONDING" or "SUBTRACT CORRESPONDING" because every potential matchup violates rule #4): A, B, C, G The following are the CORRESPONDING matchups that passed rule #1 (but failed on another rule), and the reasons why they failed. Data Item "D" "E" "F" "G1" "G2" "G3" "G4" "G5" "G6" "H" "I" "J" "K" "L" Failure Reason Fails due to rule #2b Fails due to rule #3b Fails due to rule #5 Fails due to rule #3a Fails due to rule #3a Fails due to rule #3a Fails due to rule #1 Fails due to rule #1 Fails due to rule #6 Fails due to rule #6 Fails due to rule #5 Fails due to rule #3a Fails due to rule #3a Fails due to rule #1 3 June 2014 Chapter 6 - PROCEDURE DIVISION 238 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide (cid:8) (cid:9) (cid:8) (cid:9) "M" Fails due to rule #2a 6.14.3. INVALID KEY + NOT INVALID KEY (cid:11) (cid:10) INVALID KEY Syntax [ INVALID KEY imperative-statement-1 ] ~~~~~~~ [ NOT INVALID KEY imperative-statement-2 ] ~~~ ~~~~~~~ ———————————————————————————————————————— "INVALID KEY" clauses may be specified on "DELETE" (see [DELETE], page 369), "READ" (see [Random READ], page 430), "REWRITE" (see [REWRITE], page 437), "START" (see [START], page 459) and "WRITE" (see [WRITE], page 479) statements. Specification of an "INVALID KEY" clause will allow your program to trap an I/O failure condition (with an I/O error code in the file’s "FILE-STATUS" (see [SELECT], page 73) field) that has occurred due to a record-not-found condition and handle it gracefully by executing (see [Imperative Statement], page 593). An optional "NOT INVALID KEY" clause will cause to be executed if the statement’s execution was successful. 6.14.4. ON EXCEPTION + NOT ON EXCEPTION (cid:11) (cid:10) ON EXCEPTION Syntax [ ON EXCEPTION imperative-statement-1 ] ~~~~~~~~~ [ NOT ON EXCEPTION imperative-statement-2 ] ~~~ ~~~~~~~~~ ———————————————————————————————————————— "EXCEPTION" clauses may be specified on "ACCEPT" (see [ACCEPT], page 338), "CALL" (see [CALL], page 359) and "DISPLAY" (see [DISPLAY], page 370) statements. Specification of an exception clause will allow your program to trap a failure condition that has occurred and handle it gracefully by executing (see [Imperative Statement], page 593). If such a condition occurs at runtime without hav- ing one of these clauses specified, an error message will be generated (by the GNU COBOL runtime library) to the SYSERR device (pipe 2). The program may also be terminated, depending upon the type and severity of the error. Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 239 An optional "NOT ON EXCEPTION" clause will cause to be exe- cuted if the statement’s execution was successful. 6.14.5. ON OVERFLOW + NOT ON OVERFLOW (cid:11) (cid:10) ON OVERFLOW Syntax [ ON OVERFLOW imperative-statement-1 ] ~~~~~~~~ [ NOT ON OVERFLOW imperative-statement-2 ] ~~~ ~~~~~~~~ ———————————————————————————————————————— "OVERFLOW" clauses may be specified on "CALL" (see [CALL], page 359), "STRING" (see [STRING], page 463) and "UNSTRING" (see [UNSTRING], page 475) statements. An "ON OVERFLOW" clause will allow your program to trap a failure condition that has occurred and handle it gracefully by executing (see [Imperative Statement], page 593). If such a condition occurs at runtime without having one of these clauses specified, an error message will be generated (by the GNU COBOL runtime library) to the SYSERR device (pipe 2). The program may also be terminated, depending upon the type and severity of the error. An optional "NOT ON OVERFLOW" clause will cause to be executed if the statement’s execution was successful. 6.14.6. ON SIZE ERROR + NOT ON SIZE ERROR (cid:11) (cid:10) ON SIZE ERROR Syntax [ ON SIZE ERROR imperative-statement-1 ] ~~~~ ~~~~~ [ NOT ON SIZE ERROR imperative-statement-2 ] ~~~ ~~~~ ~~~~~ ———————————————————————————————————————— "SIZE ERROR" clauses may be included on "ADD" (see [ADD], page 350), "COMPUTE" (see [COMPUTE], page 366), "DIVIDE" (see [DIVIDE], page 376), "MULTIPLY" (see [MULTIPLY], page 416) and "SUBTRACT" (see [SUBTRACT], page 465) statements. Including an "ON SIZE ERROR" clause on an arithmetic statement will allow your program to trap a failure of an arithmetic statement (either generating a result too large for the receiving field, or attempting to divide by zero) and handle it gracefully by executing (see [Imperative Statement], page 593). Field size overflow conditions occur 3 June 2014 Chapter 6 - PROCEDURE DIVISION (cid:8) (cid:9) (cid:8) (cid:9) 240 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide silently, usually without any runtime messages being generated, even though such events rarely lend themselves to generating correct results. Division by zero errors, when no "ON SIZE ERROR" clause exists, will produce an error message (by the GNU COBOL runtime library) to the SYSERR device (pipe 2) and will also abort the program. An optional "NOT ON SIZE ERROR" clause will cause to be exe- cuted if the arithmetic statement’s execution was successful. (cid:8) (cid:9) 6.14.7. ROUNDED (cid:11) (cid:10) ROUNDED Syntax ~~~~ ROUNDED [ MODE IS { AWAY-FROM-ZERO } } { ~~~~~~~~~~~~~~ ~~~~~~~ { NEAREST-AWAY-FROM-ZERO } { ~~~~~~~~~~~~~~~~~~~~~~ } } { NEAREST-EVEN } { ~~~~~~~~~~~~ } { NEAREST-TOWARD-ZERO } { ~~~~~~~~~~~~~~~~~~~ } { PROHIBITED } { ~~~~~~~~~~ } { TOWARD-GREATER } { ~~~~~~~~~~~~~~ } { TOWARD-LESSER } { ~~~~~~~~~~~~~ { TRUNCATION } ~~~~~~~~~~ ———————————————————————————————————————— GNU COBOL provides for control over the final rounding process applied to the receiv- ing fields on all arithmetic verbs. Each of the arithmetic statements ("ADD" (see [ADD], page 350), "COMPUTE" (see [COMPUTE], page 366), "DIVIDE" (see [DIVIDE], page 376), "MULTIPLY" (see [MULTIPLY], page 416) and "SUBTRACT" (see [SUBTRACT], page 465)) statements allow an optional "ROUNDED" clause to be applied to each receiving data item. The following rules apply to the rounding behavior induced by this clause. 1. Rounding only applies when the result being saved to a receiving field with a "ROUNDED" clause is a non-integer value. 2. Absence of a "ROUNDED" clause is the same as specifying "ROUNDED MODE IS TRUNCATION". 3. Use of a "ROUNDED" clause without a "MODE" specification is the same as specifying "ROUNDED MODE IS NEAREST-AWAY-FROM-ZERO". Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 241 The behavior of the eight different rounding modes is defined in the following table. Note that a ". . . " indicates the last digit repeats. The examples assume an integer receiving field. "AWAY-FROM-ZERO" Rounding is to the nearest value of larger magnitude. -3.510 ⇒ -4 -3.500 ⇒ -4 -3.499. . . ⇒ -4 -2.500 ⇒ -3 -2.499. . . ⇒ -3 "NEAREST-AWAY-FROM-ZERO" +3.510 ⇒ +4 +3.500 ⇒ +4 +3.499. . . ⇒ +4 +2.500 ⇒ +3 +2.499. . . ⇒ +3 Rounding is to the nearest value (larger or smaller). If two values are equally near, the value with the larger absolute value is selected. -3.510 ⇒ -4 -3.500 ⇒ -4 -3.499. . . ⇒ -3 -2.500 ⇒ -3 -2.499. . . ⇒ -2 "NEAREST-EVEN" +3.510 ⇒ +4 +3.500 ⇒ +4 +3.499. . . ⇒ +3 +2.500 ⇒ +3 +2.499. . . ⇒ +2 Rounding is to the nearest value (larger or smaller). If two values are equally near, the value whose rightmost digit is even is selected. This mode is sometimes called "Banker’s rounding". -3.510 ⇒ -4 -3.500 ⇒ -4 -3.499. . . ⇒ -3 -2.500 ⇒ -2 -2.499. . . ⇒ -2 "NEAREST-TOWARD-ZERO" +3.510 ⇒ +4 +3.500 ⇒ +4 +3.499. . . ⇒ +3 +2.500 ⇒ +2 +2.499. . . ⇒ +2 Rounding is to the nearest value (larger or smaller). If two values are equally near, the value with the smaller absolute value is selected. -3.510 ⇒ -4 -3.500 ⇒ -3 -3.499. . . ⇒ -3 -2.500 ⇒ -2 -2.499. . . ⇒ -2 "PROHIBITED" +3.510 ⇒ +4 +3.500 ⇒ +3 +3.499. . . ⇒ +3 +2.500 ⇒ +2 +2.499. . . ⇒ +2 No rounding is performed. If the value cannot be represented exactly in the desired format, the EC-SIZE-TRUNCATION condition (exception code 1005) 3 June 2014 Chapter 6 - PROCEDURE DIVISION 242 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide is set (and may be retrieved via the "ACCEPT" (see [ACCEPT FROM Runtime- Info], page 349) statement) and the results of the operation are undefined. -3.510 ⇒ Undefined -3.500 ⇒ Undefined -3.499. . . ⇒ Undefined -2.500 ⇒ Undefined -2.499. . . ⇒ Undefined "TOWARD-GREATER" +3.510 ⇒ Undefined +3.500 ⇒ Undefined +3.499. . . ⇒ Undefined +2.500 ⇒ Undefined +2.499. . . ⇒ Undefined Rounding is toward the nearest value whose algebraic value is larger. -3.510 ⇒ -3 -3.500 ⇒ -3 -3.499. . . ⇒ -3 -2.500 ⇒ -2 -2.499. . . ⇒ -2 "TOWARD-LESSER" +3.510 ⇒ +4 +3.500 ⇒ +4 +3.499. . . ⇒ +4 +2.500 ⇒ +3 +2.499. . . ⇒ +3 Rounding is toward the nearest value whose algebraic value is smaller. -3.510 ⇒ -4 -3.500 ⇒ -4 -3.499. . . ⇒ -4 -2.500 ⇒ -3 -2.499. . . ⇒ -3 "TRUNCATION" +3.510 ⇒ +3 +3.500 ⇒ +3 +3.499. . . ⇒ +3 +2.500 ⇒ +2 +2.499. . . ⇒ +2 Rounding is to the nearest value whose magnitude is smaller. -3.510 ⇒ -3 -3.500 ⇒ -3 -3.499. . . ⇒ -3 -2.500 ⇒ -2 -2.499. . . ⇒ -2 +3.510 ⇒ +3 +3.500 ⇒ +3 +3.499. . . ⇒ +3 +2.500 ⇒ +2 +2.499. . . ⇒ +2 Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 243 6.15. Special Registers GNU COBOL, like other COBOL dialects, includes a number of data items that are auto- matically available to a programmer without the need to actually define them in the data division. COBOL refers to such items as registers or special registers. The special registers available to a GNU COBOL program are as follows: "COB-CRT-STATUS" PIC 9(4) — This is the default data item allocated for use by the "ACCEPT " statement (see [ACCEPT screen-data-item], page 342), if no "CRT STATUS" (see [SPECIAL-NAMES], page 62) clause was specified.. "DEBUG-ITEM" Group Item — A group item in which debugging information generated by a "USE FOR DEBUGGING" section in the declaratives area of the procedure division will place information documenting why the "USE FOR DEBUGGING" procedure was invoked. Consult the "DECLARATIVES" (see [DECLARATIVES], page 208) documentation for information on the structure of this register. "LINAGE-COUNTER" BINARY-LONG SIGNED — An occurrence of this register exists for each selected file having a "LINAGE" (see [File/Sort-Description], page 94) clause. If there are multiple files whose file descriptions have "LINAGE" clauses, any explicit references to this register will require qualification (using "OF file-name"). The value of this register will be the current logical line number within the page body. The value of this register cannot be modified. "LINE-COUNTER" BINARY-LONG SIGNED — An occurrence of this register exists for each re- port defined in the program (via an "RD" (see [REPORT SECTION], page 107)). If there are multiple reports, any explicit references to this register not made in the report section will require qualification ("OF report-name"). The value of this register will be the current logical line number on the current page. The value of this register cannot be modified. "NUMBER-OF-CALL-PARAMETERS" BINARY-LONG SIGNED — This register contains the number of arguments passed to a subroutine — the same value that would be returned by the "C$NARG" built-in system subroutine (see [C$NARG], page 529). Its value will be zero when referenced in a main program. This register, when referenced from within a user-defined function, returns a value of one (1) if the function has any number of arguments and a zero if it has no arguments. 3 June 2014 Chapter 6 - PROCEDURE DIVISION 244 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide "PAGE-COUNTER" BINARY-LONG SIGNED — An occurrence of this register exists for each re- port having an "RD" (see [REPORT SECTION], page 107). If there are multiple such reports, any explicit references to this register not made in the report sec- tion will require qualification ( "OF report-name"). The value of this register will be the current report page number. The value of this register cannot be modified. "RETURN-CODE" BINARY-LONG SIGNED — This register provides a numeric data item into which a subroutine may "MOVE" (see [MOVE], page 414) a value (which will then be available to the calling program) prior to transferring control back to the program that called it, or into which a main program may "MOVE" a value before returning control to the operating system. Many built-in subroutines will return a value using this register. These values are — by convention — used to signify success (usually with a value of 0) or failure (usually with a non-zero value) of the process the program was attempting to perform. This register may also be modified by a subprogram as a result of that subprogram’s use of the "RETURNING" (see [PROCEDURE DIVISION RETURNING], page 206) clause. "SORT-RETURN" BINARY-LONG SIGNED — This register is used to report the success/fail status of a "RELEASE" (see [RELEASE], page 434) or "RETURN" (see [RETURN], page 436) statement. A value of 0 is reported on success. A value of 16 denotes failure. An "AT END" (see [AT END + NOT AT END], page 235) condition on a "RETURN" is not considered a failure. "WHEN-COMPILED" PIC X(16) — This register contains the date and time the program was com- piled in the format "mm/dd/yyhh.mm.ss". Note that only a two-digit year is provided. Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 245 6.16. Intrinsic Functions GNU COBOL supports a wide variety of "intrinsic functions" that may be used anywhere in the PROCEDURE DIVISION where a literal is allowed. For example: MOVE FUNCTION LENGTH(Employee-Last-Name) TO Employee-LN-Len Note how the word "FUNCTION" is part of the syntax when you use an intrinsic function. You can use intrinsic functions without having to include the reserved word "FUNCTION" via settings in the "REPOSITORY" (see [REPOSITORY], page 60) paragraph. You may accomplish the same thing by specifying the "-fintrinsics" switch to the GNU COBOL compiler when you compile your programs. User-written functions (see [Subprogram Types], page 557) never require the "FUNCTION" keyword when they are executed, because each user-written function a program uses must be included in that program’s "REPOSITORY" paragraph, which therefore makes the "FUNCTION" keyword optional. The following intrinsic functions, known to other "dialects" of COBOL, are defined to GNU COBOL as reserved words but are not otherwise implemented currently. Any attempts to use these functions will result in a compile-time error message. BOOLEAN-OF-INTEGER FORMATTED-CURRENT-DATE INTEGER-OF-FORMATTED-DATE CHAR-NATIONAL FORMATTED-DATE NATIONAL-OF DISPLAY-OF FORMATTED-DATETIME STANDARD-COMPARE EXCEPTION-FILE-N FORMATTED-TIME TEST-FORMATTED-DATETIME EXCEPTION-LOCATION-N INTEGER-OF-BOOLEAN The supported intrinsic functions are listed in the following sections, along with their syntax and usage notes. 3 June 2014 Chapter 6 - PROCEDURE DIVISION 246 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 6.16.1. ABS (cid:11) (cid:10) ABS(number) ~~~ ABS Function Syntax (cid:8) (cid:9) ———————————————————————————————————————— This function determines and returns the absolute value of the (a numeric literal or data item) supplied as an argument. Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 247 6.16.2. ACOS (cid:11) (cid:10) ACOS(cosine) ~~~~ ACOS Function Syntax (cid:8) (cid:9) ———————————————————————————————————————— The "ACOS" function determines and returns the trigonometric arc-cosine, or inverse cosine, of the value (a numeric literal or data item) supplied as an argument. The result will be an angle, expressed in radians. You may convert this to an angle measured in degrees, as follows: "COMPUTE = ( * 180 ) / FUNCTION PI" 3 June 2014 Chapter 6 - PROCEDURE DIVISION 248 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 6.16.3. ANNUITY (cid:11) (cid:10) ANNUITY Function Syntax ANNUITY(interest-rate, number-of-periods) ~~~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— This function returns a numeric value approximating the ratio of an annuity paid at the specified (numeric data item or literal) for each of the specified (numeric data items or literals). The is the rate of interest paid at each payment. If you only have an annual interest rate and you wish to compute monthly annuity payments, divide the annual interest rate by 12 and use that value for on this function. Multiply the result uf this function times the desired principal amount to determine the amount of each period’s payment. A note for the financially challenged: an annuity is basically a reverse loan; an accountant would take the result of this function multiplied by -1 times the principal amount to compute a loan payment you are making. Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 249 6.16.4. ASIN (cid:11) (cid:10) ASIN(sine) ~~~~ ASIN Function Syntax (cid:8) (cid:9) ———————————————————————————————————————— The "ASIN" function determines and returns the trigonometric arc-sine, or inverse sine, of the value (a numeric literal or data item) supplied as an argument. The result will be an angle, expressed in radians. You may convert this to an angle measured in degrees, as follows: "COMPUTE = ( * 180 ) / FUNCTION PI" 3 June 2014 Chapter 6 - PROCEDURE DIVISION 250 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 6.16.5. ATAN (cid:11) (cid:10) ATAN(tangent) ~~~~ ATAN Function Syntax (cid:8) (cid:9) ———————————————————————————————————————— Use this function to determine and return the trigonometric arc-tangent, or inverse tangent, of the value (a numeric literal or data item) supplied as an argument. The result will be an angle, expressed in radians. You may convert this to an angle measured in degrees, as follows: "COMPUTE = ( * 180 ) / FUNCTION PI" Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 251 6.16.6. BYTE-LENGTH (cid:11) (cid:10) BYTE-LENGTH(string) ~~~~~~~~~~~ BYTE-LENGTH Function Syntax (cid:8) (cid:9) ———————————————————————————————————————— "BYTE-LENGTH" returns the length — in bytes — of the specified (a group item, "USAGE DISPLAY" elementary item or alphanumeric literal). This intrinsic function is iden- tical to the "LENGTH-AN" (see [LENGTH-AN], page 278) function. Note that the value returned by this function is not necessarily the number of characters comprising , but rather the number of actual bytes required to store it. For example, if is encoded using a double-byte characterset such as UNICODE (where each character is represented by 16 bits of storage, not the 8-bits inherent to charac- tersets like ASCII or EBCDIC), then calling this function with a argument whose "PICTURE" (see [PICTURE], page 162) is "X(4)" would return a value of 8 rather than the value 4. Contrast this with the "LENGTH" (see [LENGTH], page 277) function. 3 June 2014 Chapter 6 - PROCEDURE DIVISION 252 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 6.16.7. CHAR (cid:11) (cid:10) CHAR(integer) ~~~~ CHAR Function Syntax (cid:8) (cid:9) ———————————————————————————————————————— This function returns the character in the ordinal position specified by the ar- gument (a numeric integer literal or data item with a value of 1 or greater) from the "COLLATING SEQUENCE" (see [OBJECT-COMPUTER], page 58) being used by the pro- gram. For example, if the program is using the (default) ASCII characterset, CHAR(34) returns the 34th character in the ASCII characterset — an exclamation-point ("!"). If you are using this function to convert a numeric value to its corresponding ASCII character, you must use an argument value one greater than the numeric value. If an argument whose value is less than 1 or greater than 256 is specified, the character in the program collating sequence corresponding to a value of all zero bits is returned. The following code is an alternative approach when you just wish to convert a number to its ASCII equivalent: 01 Char-Value. 05 Numeric-Value USAGE BINARY-CHAR. ... MOVE numeric-character-value TO Numeric-Value The "Char-Value" item now has the corresponding ASCII character value. Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 253 6.16.8. COMBINED-DATETIME (cid:11) (cid:10) COMBINED-DATETIME Function Syntax COMBINED-DATETIME(days, seconds) ~~~~~~~~~~~~~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— This function returns a 12-digit numeric result, the first seven digits of which are the integer value of the argument (a numeric data item or literal) and the last five of which are the integer value of the argument (also a numeric data item or literal). If a value less than 1 or greater than 3067671 is specified, or if a value less than 1 or greater than 86400 is specified, a value of 0 is returned and a runtime error will result. 3 June 2014 Chapter 6 - PROCEDURE DIVISION 254 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 6.16.9. CONCATENATE (cid:11) (cid:10) CONCATENATE Function Syntax CONCATENATE(string-1 [, string-2 ]...) ~~~~~~~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— This function concatenates the , , . . . (group items, "USAGE DISPLAY" elementary items and/or alphanumeric literals) together into a single string result. If a numeric literal or "PIC 9" identifier is specified as an argument, decimal points, if any, will be removed and negative signs in "PIC S9" fields or numeric literals will be inserted as defined by the "SIGN IS" (see [SIGN IS], page 177) clause (or absence thereof) of the field. Numeric literals are processed as if "SIGN IS TRAILING SEPARATE" were in effect. Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 255 6.16.10. COS (cid:11) (cid:10) COS(angle) ~~~ COS Function Syntax (cid:8) (cid:9) ———————————————————————————————————————— The "COS" function determines and returns the trigonometric cosine of the (a numeric literal or data item) supplied as an argument. The is assumed to be a value expressed in radians. If you need to determine the cosine of an angle measured in degrees, you first need to convert that angle to radians as follows: "COMPUTE = ( * FUNCTION PI) / 180" 3 June 2014 Chapter 6 - PROCEDURE DIVISION 256 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 6.16.11. CURRENCY-SYMBOL (cid:11) CURRENCY-SYMBOL Function Syntax (cid:10) CURRENCY-SYMBOL ~~~~~~~~~~~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— The "CURRENCY-SYMBOL" function returns the currency symbol character currently in effect for the locale under which your program is running. On UNIX systems, your locale is established via the "LANG" run-time environment variable (see [Run Time Environment Variables], page 522) environment variable. On Windows, the Control Panel’s "Regional and Language Options" define the locale. Changing the currency symbol via the "SPECIAL-NAMES" (see [SPECIAL-NAMES], page 62) paragraph’s "CURRENCY SYMBOL" setting will not affect the value returned by this function. Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 257 6.16.12. CURRENT-DATE (cid:11) (cid:10) CURRENT-DATE ~~~~~~~~~~~~ CURRENT-DATE Function Syntax (cid:8) (cid:9) ———————————————————————————————————————— Returns the current date and time as the following 21-character structure: 01 CURRENT-DATE-AND-TIME. 05 CDT-Year 05 CDT-Month 05 CDT-Day 05 CDT-Hour 05 CDT-Minutes 05 CDT-Seconds 05 CDT-Hundredths-Of-Secs 05 CDT-GMT-Diff-Hours 05 CDT-GMT-Diff-Minutes PIC 9(4). PIC 9(2). *> 01-12 PIC 9(2). *> 01-31 PIC 9(2). *> 00-23 PIC 9(2). *> 00-59 PIC 9(2). *> 00-59 PIC 9(2). *> 00-99 PIC S9(2) SIGN LEADING SEPARATE. PIC 9(2). *> 00 or 30 Since this function has no arguments, no parenthesis should be specified. 3 June 2014 Chapter 6 - PROCEDURE DIVISION 258 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 6.16.13. DATE-OF-INTEGER (cid:11) (cid:10) DATE-OF-INTEGER Function Syntax DATE-OF-INTEGER(integer) ~~~~~~~~~~~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— This function returns a numeric calendar date in yyyymmdd (i.e. Gregorian) format. The date is determined by adding the number of days specified as (a numeric integer data item or literal) to the date December 31, 1600. For example, "DATE-OF-INTEGER(1)" returns 16010101 while "DATE-OF-INTEGER(150000)" returns 20110908. A value less than 1 or greater than 3067671 (9999/12/31) will return a result of 0. Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 259 6.16.14. DATE-TO-YYYYMMDD (cid:11) (cid:10) DATE-TO-YYYYMMDD Function Syntax DATE-TO-YYYYMMDD(yymmdd [, yy-cutoff ]) ~~~~~~~~~~~~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— You can use this function to convert the six-digit Gregorian date specified as (a numeric integer data item or literal) to an eight-digit format (yyyymmdd). The optional (a numeric integer data item or literal) argument is the year cutoff used to delineate centuries; if the year component of the date meets or exceeds this cutoff value, the result will be 19yymmdd; if the year component of the date is less than the cutoff value, the result will be 20yymmdd. The default cutoff value if no second argument is given will be 50. 3 June 2014 Chapter 6 - PROCEDURE DIVISION 260 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 6.16.15. DAY-OF-INTEGER (cid:11) DAY-OF-INTEGER Function Syntax (cid:10) DAY-OF-INTEGER(integer) ~~~~~~~~~~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— This function returns a calendar date in yyyyddd (i.e. Julian) format. The date is deter- mined by adding the number of days specified as integer (a numeric integer data item or literal) to December 31, 1600. For example, "DAY-OF-INTEGER(1)" returns 1601001 while "DAY-OF-INTEGER(250000)" returns 2011251. A value less than 1 or greater than 3067671 (9999/12/31) will return a result of 0. Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 261 6.16.16. DAY-TO-YYYYDDD (cid:11) (cid:10) DAY-TO-YYYYDDD Function Syntax DAY-TO-YYYYDDD(yyddd [, yy-cutoff]) ~~~~~~~~~~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— You can use this function to convert the five-digit Julian date specified as (a numeric integer data item or literal) to a seven-digit numeric Julian format (yyyyddd). The optional argument (a numeric integer data item or literal) is the year cutoff used to delineate centuries; if the year component of the date meets or exceeds this cutoff value, the result will be 19yyddd; if the year component of the date is less than the cutoff, the result will be 20yyddd. The default cutoff value if no second argument is given will be 50. 3 June 2014 Chapter 6 - PROCEDURE DIVISION 262 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 6.16.17. E (cid:11) (cid:10) E ~ E Function Syntax (cid:8) (cid:9) ———————————————————————————————————————— function returns This arithms). 2.7182818284590452353602874713526625. log- The maximum precision with which this value may be returned is the mathematical constant "E" (the base of natural Since this function has no arguments, no parenthesis should be specified. Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 263 6.16.18. EXCEPTION-FILE (cid:11) EXCEPTION-FILE Function Syntax (cid:10) EXCEPTION-FILE ~~~~~~~~~~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— This function returns I/O exception information from the most-recently executed input or output statement. The information is returned as a 34-character string, where the first two characters are the two-digit file status value (see [File Status Codes], page 76) and the remaining 32 are the specification from the file’s "SELECT" (see [SELECT], page 73) statement. The name returned after the file status information will be returned only if the returned file status value is not 00. Since this function has no arguments, no parenthesis should be specified. The documentation of [CBL ERROR PROC], page 536) built-in subroutine illustrates the use of this function. the "CBL_ERROR_PROC" built-in system subroutine (see 3 June 2014 Chapter 6 - PROCEDURE DIVISION 264 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 6.16.19. EXCEPTION-LOCATION (cid:11) EXCEPTION-LOCATION Function Syntax (cid:10) EXCEPTION-LOCATION ~~~~~~~~~~~~~~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— This function returns exception information from the most-recently failing statement. The information is returned to a 1023 character string in one of the following formats, depending on the nature of the failure: • primary-entry-point-name; paragraph OF section; statement-number • primary-entry-point-name; section; statement-number • primary-entry-point-name; paragraph; statement-number • primary-entry-point-name; statement-number Since this function has no arguments, no parenthesis should be specified. The program must be compiled with the "-debug" switch, "-ftraceall" switch or "-g" switch for this function to return any meaningful information. The documentation of [CBL ERROR PROC], page 536) built-in subroutine illustrates the use of this function. the "CBL_ERROR_PROC" built-in system subroutine (see Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 265 6.16.20. EXCEPTION-STATEMENT (cid:11) EXCEPTION-STATEMENT Function Syntax (cid:10) EXCEPTION-STATEMENT ~~~~~~~~~~~~~~~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— This function returns the most-recent COBOL statement that generated an exception con- dition. Since this function has no arguments, no parenthesis should be specified. The program must be compiled with the "-debug" switch, "-ftraceall" switch or "-g" switch for this function to return any meaningful information. The documentation of [CBL ERROR PROC], page 536) built-in subroutine illustrates the use of this function. the "CBL_ERROR_PROC" built-in system subroutine (see 3 June 2014 Chapter 6 - PROCEDURE DIVISION 266 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 6.16.21. EXCEPTION-STATUS (cid:11) EXCEPTION-STATUS Function Syntax (cid:10) EXCEPTION-STATUS ~~~~~~~~~~~~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— This function returns the error type (a text string — see column 2 of the upcoming table for the possible values) from the most-recent COBOL statement that generated an exception condition. Since this function has no arguments, no parenthesis should be specified. The documentation of [CBL ERROR PROC], page 536) built-in subroutine illustrates the use of this function. the "CBL_ERROR_PROC" built-in system subroutine (see The following are the error type strings, and their corresponding exception codes and de- scriptions. Code Error Type Description 0101 0202 EC-ARGUMENT- FUNCTION EC-BOUND-ODO Function argument error OCCURS . . . DEPENDING ON data item out of bounds 0204 EC-BOUND-PTR Data-pointer contains an address that is out of bounds 0205 EC-BOUND-REF-MOD Reference modifier out of bounds 0207 EC-BOUND-SUBSCRIPT Subscript out of bounds 0303 EC-DATA-INCOMPATIBLE Incompatible data exception 0500 EC-I-O input-output exception 0501 EC-I-O-AT-END I-O status "1x" 0502 EC-I-O-EOP An end of page condition occurred 0504 EC-I-O-FILE-SHARING I-O status "6x" 0505 EC-I-O-IMP I-O status "9x" Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 267 0506 EC-I-O-INVALID-KEY I-O status "2x" 0508 EC-I-O-LOGIC-ERROR I-O status "4x" 0509 050A 0601 EC-I-O-PERMANENT- ERROR EC-I-O-RECORD- OPERATION EC-IMP-ACCEPT I-O status "3x" I-O status "5x" Implementation-defined accept condition 0602 EC-IMP-DISPLAY Implementation-defined display condition 0A00 EC-OVERFLOW Overflow condition 0A02 EC-OVERFLOW-STRING STRING overflow condition 0A03 0B05 0D03 1000 EC-OVERFLOW- UNSTRING EC-PROGRAM-NOT- FOUND EC-RANGE-INSPECT- SIZE EC-SIZE UNSTRING overflow condition Called program not found Size of replace item in inspect differs Size error exception 1004 EC-SIZE-OVERFLOW Arithmetic overflow in calculation 1005 EC-SIZE-TRUNCATION Significant digits truncated in store 1007 EC-SIZE-ZERO-DIVIDE Division by zero 1202 EC-STORAGE-NOT- ALLOC The data-pointer specified in a FREE statement does not identify currently allocated storage 1203 EC-STORAGE-NOT-AVAIL The amount of storage requested by an ALLO- CATE statement is not available 3 June 2014 Chapter 6 - PROCEDURE DIVISION 268 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 6.16.22. EXP (cid:11) (cid:10) EXP(number) ~~~ EXP Function Syntax (cid:8) (cid:9) ———————————————————————————————————————— Computes and returns the value of the mathematical constant "e" raised to the power specified by (a numeric literal or data item). Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 269 6.16.23. EXP10 (cid:11) (cid:10) EXP10(number) ~~~~~ EXP10 Function Syntax (cid:8) (cid:9) ———————————————————————————————————————— Computes and returns the value of 10 raised to the power specified by (a numeric literal or data item). 3 June 2014 Chapter 6 - PROCEDURE DIVISION 270 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 6.16.24. FACTORIAL (cid:11) (cid:10) FACTORIAL(number) ~~~~~~~~~ FACTORIAL Function Syntax (cid:8) (cid:9) ———————————————————————————————————————— This function computes and returns the factorial value of (a numeric literal or data item). Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 271 6.16.25. FRACTION-PART (cid:11) FRACTION-PART Function Syntax (cid:10) FRACTION-PART(number) ~~~~~~~~~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— This function returns that portion of (a numeric data item or a numeric literal) that occurs to the right of the decimal point. "FRACTION-PART(3.1415)", for example, returns a value of 0.1415. This function is equivalent to the expression: -- FUNCTION INTEGER-PART() 3 June 2014 Chapter 6 - PROCEDURE DIVISION 272 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 6.16.26. HIGHEST-ALGEBRAIC (cid:11) (cid:10) HIGHEST-ALGEBRAIC Function Syntax HIGHEST-ALGEBRAIC(numeric-identifier) ~~~~~~~~~~~~~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— This function returns the highest (i.e. largest or farthest away from 0 in a positive direction if is signed) value that could possibly be stored in the specified . Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 273 6.16.27. INTEGER (cid:11) (cid:10) INTEGER(number) ~~~~~~~ INTEGER Function Syntax (cid:8) (cid:9) ———————————————————————————————————————— The "INTEGER" function returns the greatest integer value that is less than or equal to (a numeric literal or data item). 3 June 2014 Chapter 6 - PROCEDURE DIVISION 274 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 6.16.28. INTEGER-OF-DATE (cid:11) INTEGER-OF-DATE Function Syntax (cid:10) INTEGER-OF-DATE(date) ~~~~~~~~~~~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— This function converts (a numeric integer data item or literal) — presumed to be a Gregorian calendar form standard date (YYYYMMDD) — to internal date form (the number of days that have transpired since 1600/12/31). Once in that form, mathematical operations may be performed against the internal date before it is transformed back into a date using the "DATE-OF-INTEGER" (see [DATE-OF- INTEGER], page 258) or "DAY-OF-INTEGER" (see [DAY-OF-INTEGER], page 260) func- tion. Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 275 6.16.29. INTEGER-OF-DAY (cid:11) INTEGER-OF-DAY Function Syntax (cid:10) INTEGER-OF-DAY(date) ~~~~~~~~~~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— This function converts (a numeric integer data item or literal) — presumed to be a Julian calendar form standard date (YYYYDDD) — to internal date form (the number of days that have transpired since 1600/12/31). Once in that form, mathematical operations may be performed against the internal date before it is transformed back into a date using the "DATE-OF-INTEGER" (see [DATE-OF- INTEGER], page 258) or "DAY-OF-INTEGER" (see [DAY-OF-INTEGER], page 260) func- tion. 3 June 2014 Chapter 6 - PROCEDURE DIVISION 276 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 6.16.30. INTEGER-PART (cid:11) INTEGER-PART Function Syntax (cid:10) INTEGER-PART(number) ~~~~~~~~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— Returns the integer portion of the value of (a numeric literal or data item). Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 277 6.16.31. LENGTH (cid:11) (cid:10) LENGTH(string) ~~~~~~ LENGTH Function Syntax (cid:8) (cid:9) ———————————————————————————————————————— Returns the length — in characters — of (a group item, "USAGE DISPLAY" ele- mentary item or alphanumeric literal). The value returned by this function is not the number of bytes of storage occupied by string, but rather the number of actual characters making up the string. For example, if is encoded using a double-byte characterset such as UNICODE (where each character is represented by 16 bits of storage, not the 8-bits inherent to charactersets like ASCII or EBCDIC), then calling this function with a argument whose "PICTURE is X(4)" would return a value of 4 rather than the value 8 (the actual number of bytes of storage occupied by that item). Comtrast this function with the "BYTE-LENGTH" (see [BYTE-LENGTH], page 251) and "LENGTH-AN" (see [LENGTH-AN], page 278) functions. 3 June 2014 Chapter 6 - PROCEDURE DIVISION 278 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 6.16.32. LENGTH-AN (cid:11) (cid:10) LENGTH-AN(string) ~~~~~~~~~ LENGTH-AN Function Syntax (cid:8) (cid:9) ———————————————————————————————————————— This function returns the length — in bytes of storage — of (a group item, "USAGE DISPLAY" elementary item or alphanumeric literal). This intrinsic function is identical to the "BYTE-LENGTH" (see [BYTE-LENGTH], page 251) function. Note that the value returned by this function is not the number of characters making up the , but rather the number of actual bytes of storage required to store . For example, if is encoded using a double-byte characterset such as UNICODE (where each character is represented by 16 bits of storage, not the 8-bits inherent to charac- tersets like ASCII or EBCDIC), then calling this function with a argument whose "PICTURE is X(4)" would return a value of 8 rather than the value 4. Contrast this with the "LENGTH" (see [LENGTH], page 277) function. Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 279 6.16.33. LOCALE-COMPARE (cid:11) (cid:10) LOCALE-COMPARE Function Syntax LOCALE-COMPARE(argument-1, argument-2 [ , locale ]) ~~~~~~~~~~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— The "LOCALE-COMPARE" function returns a character indicating the result of comparing and using a culturally-preferred ordering defined by a . Either or both of the 1st two arguments may be an alphanumeric literal, a group item or an elementary item appropriate to storing alphabetic or alphanumeric data. If the lengths of the two arguments are unequal, the shorter will be assumed to be padded to the right with spaces. The two arguments will be compared, character by character, against each other until their relationship to each other can be determined. The comparison is made according to the cultural rules in effect for the specified name or for the current locale if no argument is specified. Once that relationship is determined, a one-character alphanumeric value will be returned as follows: • "<" — If is determined to be less than • "=" — If the two arguments are equal to each other • ">" — If is determined to be greater than See [LOCALE Names], page 64, for a list of typically-available locale names. 3 June 2014 Chapter 6 - PROCEDURE DIVISION 280 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 6.16.34. LOCALE-DATE (cid:11) (cid:10) LOCALE-DATE Function Syntax LOCALE-DATE(date [, locale ]) ~~~~~~~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— Converts the eight-digit Gregorian (a numeric integer data item or literal) from yyyymmdd format to the format appropriate to the current locale. On a Windows system, this will be the "short date" format as set using Control Panel. You may include an optional second argument to specify the name (group item or "PIC X" identifier) you’d like to use for date formatting. If used, this second argument must be an identifier. Locale names are specified using UNIX-standard names. Chapter 6 - PROCEDURE DIVISION 3 June 2014 GNU COBOL 2.1 [23NOV2013] Programmer’s Guide 281 6.16.35. LOCALE-TIME (cid:11) (cid:10) LOCALE-TIME Function Syntax LOCALE-TIME(time [, locale ]) ~~~~~~~~~~~ (cid:8) (cid:9) ———————————————————————————————————————— Converts the four- (hhmm) or six-digit (hhmmss)