It is possible, for each individual output device, to define whether SPOOL outputs on this device are to be processed using exit routines (see the START-PRINTER-OUTPUT command).
Querying the current SPOOL version
The SPOOL (and RSO) exit routines must query the numbers of the current SPOOL version in the SCB.
Exit routines are loaded, activated and deactivated independently of the DSSM commands START-SUBSYSTEM, STOP-SUBSYSTEM, HOLD-SUBSYSTEM and RESUME-SUBSYSTEM. As a result, SPOOL can be unloaded and replaced by another version, while the exit routines remain activated and can be called later by the newly loaded SPOOL version.
The exit routines have to be able to recognize this change to the SPOOL version; to this end they check the version specification stored in the SCB.
The version number is contained in the SCBESCB field of the DSECT, which can be created using the SSVSCB macro.
If system exits 90, 91 and 92 are active at the same time, the calls occur in the following order:
Exit 90: First call
Exit 91: Header page routine
Exit 90: Processing routine
Exit 92: Trailer page routine
Exit 90: Final call.
The first call has already been processed when the file is opened. The next step is to format the header page.
Once the trailer page has been generated, the final call is issued and the file is closed.
Independently of this sequence, system exit 95 may have been activated in order to monitor channel programs sent to the printers.
In the case of “family” processing, a header can be generated either for the first file only or for every file in the family. By means of an SPSINF call (INFO=SPSGEN) in the exit routine you can read the GEN entry and thus obtain the information you require.
If GENFAM=YES is set in the GEN entry, a header page is printed for each file in the “family” printout; otherwise only a header page for the first file will be printed (i.e. if the field SCBESEQ#=0 is set in the SCB).
Systems support staff can use exit 094 to generate a user routine for assistance in controlling the conversion of resources within a client/server environment in conjunction with the product Distributed Print Services (Dprint).
Using exit 096 in conjunction with the product Distributed Print Services enables systems support staff to select particular servers by combining the appropriate selection criteria.
Exit 097 can be used to control the number of jobs of the product Dprint (Distributed Print Services) for file transfer.
Note
The descriptions on the following pages refer to the new PRINT-DOCUMENT command or PRNTDOC macro introduced with SPOOL V3.0. The exit functions can be used in the same way with the old PRINT-FILE command or the old PRNT macro. More detailed information on SPOOL can be found in the manual “SPOOL” [13]. For Dprint exits please use the description given in the manual “Distributed Print Services” [5].