File Section - COBOL

The File Section header is followed by file description entries or sort-merge file description entries consisting of a level indicator (FD and SD, respectively), a file-name and a series of independent clauses, terminated by a period. Each file description entry or sort-merge description entry is followed by one or more record description entries.

The file description entry and sort-merge file description entry (FD and SD) are the highest level of organization in the File Section.

A Format 1 (data item initialization) VALUE clause specified in the File Section is ignored except in the execution of the INITIALIZE statement.The initial value of a data item in the File Section is undefined.

File Description Entry

The file description entry furnishes information concerning the physical structure, identification and record names pertaining to a given file.

The level indicator FD identifies the beginning of a file description and must precede the file-name.

The clauses that follow the name of the file are optional and their order of appearance is not significant.

The LINAGE clause may be used only if file-name-1 references a sequential file. If the file description entry for a sequential file contains the LINAGE clause and the EXTERNAL clause, the LINAGE-COUNTER data item is an external data item. If the file description entry for a sequential file contains the LINAGE clause and the GLOBAL clause, the special register LINAGE-COUNTER is a global name.

One or more record description entries must follow the file description entry.

A file description entry must end with a period separator.

Sort-Merge File Description Entry

The sort-merge file description entry furnishes information concerning the physical structure, identification, and record-names of the file to be sorted or merged.

The level indicator SD identifies the beginning of the sort-merge file description and must precede the file-name.

The clauses that follow the name of the file are optional and their order of appearance is immaterial.

One or more record description entries must follow the sort-merge file description entry. Within the Procedure Division, file-name-1 may not be used in OPEN, CLOSE, READ, START, DELETE or UNLOCK statements, nor may subordinate record-names be used in WRITE or REWRITE statements.