File specification

There are some differences between the way COBOL for AIX handles files and the way host COBOL handles files.

The differences between COBOL for AIX and host COBOL in file handling are in the following areas:

Single-volume files: COBOL for AIX treats all files as single-volume files. All other file specifications are treated as comments. This difference affects the following items: REEL, UNIT, MULTIPLE FILE TAPE clause, and CLOSE. . .UNIT/REEL.

Source-file suffixes: In COBOL for AIX, when you compile using one of the cob2 commands, COBOL source files that either have suffix .cbl or .cob are passed to the compiler. In host COBOL, when you compile in the z/OS UNIX file system, only files that have suffix .cbl are passed to the compiler.

Generation data groups (GDGs): GDG support is almost identical to GDG support in host COBOL. However, there are differences in COBOL for AIX:

File concatenation: In COBOL for AIX, you concatenate multiple files by separating the file identifiers with a colon (:). A COBOL file that is concatenated must have sequential or line-sequential organization, must be accessed sequentially, and can be opened only for input.

related concepts  
Generation data groups