File Management - IBM

26 File Management V4R5
Table 6. OS/400 File Management Message Number Ranges
Message IDs Operation Message Type
CPF4001-40FF Open Diagnostic and status.
CPF4101-43FF Open Escapes that make the file
unusable.
CPF4401-44FF Close Diagnostic and status.
CPF4501-46FF Close Escapes that make the file
unusable.
CPF4701-48FF I/O, Acquire, and Release Notify with a default reply of
cancel, status and escapes
that do not make the file or
device unusable.
CPF4901-49FF I/O, Acquire, and Release Notify with a default reply of
ignore or go.
CPF5001-50FF I/O, Acquire, and Release Notify with a default reply of
cancel.
CPF5101-53FF I/O, Acquire, and Release Escapes that make the file or
device unusable.
CPF5501-56FF I/O, Acquire, and Release Escapes that make the file or
device unusable.
Some status messages, CPF4018 for example, are preceded by a diagnostic message
that provides additional information. Diagnostic messages may be kept in the job
log, depending on the message logging level of the job. If a CL program monitors
for CPF4018, CPF5041, or similar messages, it can retrieve the accompanying
diagnostic message from the program message queue.
If an error occurs for which an escape message is issued and the message is not
monitored, your program will be ended and the message displayed for the
operator. You can also monitor status messages, but if you do not monitor them
the program continues. Most high-level languages except CL monitor for all the file
errors that you are likely to encounter, and provide some standard recovery.
Depending on the severity of the error, the high-level language may simply end
the program and issue a message of its own. Alternatively, the application
programmer may code an error recovery routine to handle errors that are
anticipated in that particular application.
Within these error-handling routines, it is usually necessary to examine the file
status or major and minor return codes to determine the cause of the error. The
books for the language you are using explain how to access file status and major
and minor return codes. The information for each language also explains the file
status codes as each language defines them.
Major and minor return codes in files by the system
Major and minor return codes report errors and certain status information for ICF,
display, and printer files. They are not used for other files. They usually appear as