File processing

The DMS macros for file processing (i.e. the “service macros”) are macro calls which are valid for all access methods.

Macro	Brief description
FCB	Creates a file control block (FCB).
FCBAD	Creates the FCB in the literal pool of a program.
OPEN	Opens a file.
CLOSE	Closes one or more files.
EXLST	Defines error exits.
EXRTN	Implements a return from EXLST routines.
LBRET	Implements a return from user label handling routines (tape processing).