DUMMY files

Dummy files can be used for test purposes, particularly for testing error routines in user programs. These dummy files are defined by *DUMMY in the FILE macro and ADD-FILE-LINK command. No actual I/O operations are executed when these files are processed. Any attempt to read such a file causes control to be passed to an error routine and write attempts are ignored, i.e. in each case a no-op (i.e. no operation) is executed.

The following table shows which events occur for the various ISAM read operations.

Read operation	Macro	Event	EXLST exit	Message
Sequential read	GET/GETR	End of file	EOFADDR	DMS0AAE
Read with key	GETKY	Key not found	NOFIND	DMS0AA8
Read with flags	GETFL LIMIT=KEY LIMIT=END	Key not found End of file	NOFIND EOFADDR	DMS0AA8 DMS0AAE

Table 60: ISAM read operations for dummy files