In addition to the system syntax files, there may be one group syntax file and one or more user syntax files active for each user task. In this case, a file hierarchy determines how SDF uses the various syntax files. System syntax files and group syntax files can be activated by means of the MODIFY-SDF-PARAMETERS command, user syntax files with the MODIFY-SDF-OPTIONS command. The names of the system syntax files and the group syntax files to be activated are entered in an SDF parameter file.
The basic system syntax file is automatically activated when SDF is loaded. The same applies to the subsystem syntax files if they are named in the SDF parameter file, i.e. when their names are entered in the SDF parameter file.
If no parameter file is specified in the DSSM declaration for SDF, then $TSOS.SYSPAR.SDF is used as the parameter file. If the parameter file does not have any valid contents, then a new name is requested via console message CMD0691. When “*STD“ is the reply, $TSOS.SYSSDF.SDF.048 is activated as the basic system syntax file (and $TSOS.SYSSDF.BS2CP.<bs2vers> is activated as a subsystem syntax file).
The activated basic system syntax file can be switched during the session by system administration (with the MODIFY-SDF-PARAMETERS command). The basic system syntax file activated during a session with MODIFY-SDF-PARAMETERS may have any name.
System administration assigns a group syntax file to a profile ID and can change this assignment during the session with the aid of the MODIFY-SDF-PARAMETERS command. The SCOPE operand defines this assignment as permanent, permanent as of the next session, or valid for the current session only.
The group syntax file assigned in this way is activated automatically after LOGON processing for each task under a user ID with the corresponding profile ID.
A warning is output if the SDF parameter file does not exist or is invalid.
User syntax files are linked to a user ID. If a user syntax file is to be activated automatically after LOGON processing, it must be cataloged under the name $<userid>.SDF.USER.SYNTAX. The user may activate or deactivate user syntax files during execution of a user task (with MODIFY-SDF-OPTIONS). If a user syntax file is activated with MODIFY-SDF-OPTIONS, it may have any desired name.