IBM OS/390 User Manual

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12.4.5.2 File Attribute Mismatches
DOS/VS COBOL file open processing does not always check that the attributes of
the file definition in your program exactly match the file attributes of the physical
file (for example, as defined for a VSAM file in the LISTCAT). To conform with
ANSI 85 requirements, COBOL for OS/390 and VM open processing carries out
many detailed checks for consistency between the program and actual file
definition before opening the file. This can result in file open failures in COBOL
for OS/390 and VM for files that were opened successfully in DOS/VS COBOL.
You should add a file status check to your code following each OPEN statement.
If these subsequently indicate problems you can amend your program
accordingly.
12.4.5.3 ISAM
DOS/VS COBOL supports the processing of ISAM files, however COBOL for
OS/390 and VM does not. Any ISAM files should be converted to VSAM Keyed
Sequential Data Sets (VSAM/KSDS). CCCA/VSE can automatically convert the
file definition and I/O statements from ISAM to VSAM/KSDS.
12.5 Converting from VS COBOL II
If your VS COBOL II source is VS COBOL II Release 4 and has been compiled
with the NOCMPR2 option, then it is upward-compatible with COBOL for
VSE/ESA, which, as we said earlier, is compatible with COBOL for OS/390 and
VM. You can transfer your source code to your OS/390 system and recompile
and linkedit it.
If you prefer, you can transfer the compiled object code to OS/390 for linkediting.
See 12.2, “VSE to OS/390 Migration Considerations” on page 250.
However, if you are using LE/VSE callable services, you may need to change
their names. Callable services which have names in LE/VSE beginning with
CEE5.... are named CEE3.... in OS/390 Language Environment. These names will
require changing and these programs will have to be recompiled in OS/390. You
will not be able to transfer the compiled object code for these programs to
OS/390. Refer to Chapter 17, “Language Environment (LE)” on page 351 for
more information about migrating your run-time to Language Environment.
There are two new reserved words in COBOL for VSE/ESA, which you may need
to consider in your conversion. They are:
PROCEDURE-POINTER
FUNCTION
If your VS COBOL II source is VS COBOL II Release 3.2, then, as well as the two
reserved words mentioned above, there are three minor COBOL ANSI 85
Standard interpretation changes. These Standard interpretation changes affect
the following language elements:
REPLACE and Comment Lines
Precedence of USE Procedures
Reference Modification of a Variable-Length Group
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VSE to OS/390 Migration Workbook