File specification
There are some differences between the way COBOL for Linux® on x86 handles files and the way Enterprise COBOL handles files.
The differences between COBOL for Linux on x86 and Enterprise COBOL in file handling are in the following areas:
- Single-volume files
- Source-file suffixes
- Generation data groups (GDGs)
- File concatenation
Single-volume files:
COBOL for Linux on x86 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 Linux on x86, 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 Enterprise 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 Enterprise COBOL. However, there are differences in COBOL for Linux on x86:
- Generation data sets (GDSs), or generation files as they are referred to in this information, are supported for all file organizations and access modes in all the supported file systems.
- GDG support is not integrated into the file systems. A stand-alone
utility,
gdgmgr
, is provided for creating and deleting GDGs, managing and querying GDG entries, performing limit processing, and reconciling the GDG catalog against the existing files. - The resolution of generation file names occurs when the files are opened rather than at job initialization.
- Limit processing is done when a new generation is added to a group, rather than at job termination.
- The generational range within any given epoch is from 1 to 9999, inclusive, instead of being limited to 1000. Therefore generations 0001 and 9999 can exist in the same epoch.
- A group can contain 1000 generations instead of 255.
- Versioning is not supported.
The automatically generated version
is always
v00
.
File concatenation: In COBOL for Linux on x86, 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.