An example of a printer exit module, sampprnx.cbl, is provided in the /src/enterpriseserver/exit sub-directory of your product installation directory by default. This example simply takes each line and calls the COBOL run-time system's print routines to print it.
Printer exits need not be written in COBOL, but they must handle parameters as illustrated in sampprnx. These parameters are defined and documented in the cascbprn.cpy copybook. COBOL printer exits must be compiled with the non-mainframe dialect, which implies CHARSET(ASCII). They must be also built as an .int, a .gnt, or a .dll.
The linkage section of sampprnx, and the cascbprn.cpy are shown below.
linkage section. copy 'cascbprn.cpy' replacing ==(ws)== by ==lk==. 01 lk-catalog-rec. copy 'mvscatlg.cpy' replacing ==(TAG)== by ==lk==. 01 LK-OUTPUT. copy mvsdout replacing ==()== by ==LK-OUTPUT==. 01 LK-SPOOL. copy 'spool.cpy' replacing ==(tag)== by ==lk==. 01 extended-output. copy 'outpext.cpy'.
01 (ws)-prn-exit-interface.
*> What is the format of the structure used to call the
*> printer exit. Will change with major revisions to this
*> Data Structure.
03 (ws)-prn-version pic x(4) comp-5.
88 (ws)-prn-current-version-88 value 1.
*> The printer exit is driven once as the batch printer SEP
*> starts, once for every print job, and once when the batch
*> printer is shut down.
03 (ws)-prn-command pic x comp-5.
88 (ws)-prn-exit-init-88 value 0.
88 (ws)-prn-exit-print-88 value 1.
88 (ws)-prn-exit-term-88 value 2.
*> For the requested print job. (ws)-prn-exit-print-88
*> what is the character set of the data being printed.
03 (ws)-prn-char pic x.
88 (ws)-prn-char-ascii-88 value 'A'.
88 (ws)-prn-char-ebcdic-88 value 'E'.
88 (ws)-prn-char-unknown-88 value '?'.
*> This is the file status returned by driving the procedure
*> pointers:
*> (ws)-prn-sysout-open-pptr
*> (ws)-prn-sysout-read-next-pptr
*> (ws)-prn-sysout-close-pptr
*>
03 (ws)-prn-sysout-status pic x(2).
88 (ws)-prn-sysout-status-ok-88 value '00'.
88 (ws)-prn-sysout-status-eof-88 value '10'.
***--------------------------------------------------------------*
*> Procedure pointer to drive the open of the sysout dataset
*> (ws)-prn-exit-print-88 only
03 (ws)-prn-sysout-open-pptr procedure-pointer.
*> Procedure pointer to a read of the sysout dataset
*> (ws)-prn-exit-print-88 only
03 (ws)-prn-sysout-read-next-pptr procedure-pointer.
*> Procedure pointer to drive the close of the sysout dataset
*> (ws)-prn-exit-print-88 only
03 (ws)-prn-sysout-close-pptr procedure-pointer.
*> Procedure pointer to allow a message to be driven to the
*> console. (all functions)
03 (ws)-prn-message-pptr procedure-pointer.
*> Procedure pointer to retrieve the next OUTPUT statement.
*> Returns a null (ws)-prn-output-record-ptr if none are
*> available.
*> (ws)-prn-exit-print-88 only
03 (ws)-prn-output-read-next-pptr procedure-pointer.
03 procedure-pointer.
03 procedure-pointer.
***--------------------------------------------------------------*
*> A pointer to the data structure contained in Spool.cpy
*> (ws)-prn-exit-print-88 only
03 (ws)-prn-spool-record-ptr pointer.
*> A pointer to the data structure contained in mvscatlg.cpy
*> (ws)-prn-exit-print-88 only
03 (ws)-prn-catalog-record-ptr pointer.
*> The printer handle for the printer assigned to the this SEP
03 (ws)-prn-printer-handle pic x(4) comp-5.
*> The LRECL of the dataset being printed.
*> (ws)-prn-exit-print-88 only
03 (ws)-prn-lrecl pic x(4) comp-5.
*> The Maximum LRECL of the dataset being printed.
*> Same as ws-prn-lrecl.
*> (ws)-prn-exit-print-88 only
03 (ws)-prn-lrecl-max pic x(4) comp-5.
*> The Minimum LRECL of the dataset being printed.
*> (Variable Length SYSOUT Datasets.
*> (ws)-prn-exit-print-88 only
03 (ws)-prn-lrecl-min pic x(4) comp-5.
03 (ws)-prn-file-disp pic x.
*> set to '1' to delete spool file on return
03 pic x(3).
*> The length of the buffer used to return data when driving
*> (ws)-prn-sysout-read-next-pptr
*> (How much data was returned)
*> (ws)-prn-exit-print-88 only
03 (ws)-prn-buffer-len pic x(4) comp-5.
03 (ws)-prn-buffer.
05 (ws)-prn-buffer-byte occurs 384 times pic x comp-x.
*> The "MVS" Name of the document being printed.
*> (ws)-prn-exit-print-88 only
03 (ws)-prn-document.
05 (ws)-prn-document-len pic x(2) comp-5.
05 (ws)-prn-document-title pic x(128).
*> The name of the batch printer driving this print job.
03 (ws)-prn-printer.
05 (ws)-prn-printer-name-len pic x(2) comp-5.
05 (ws)-prn-printer-name pic x(128).
*> The "physical" filename for the file being printed.
*> (eg. Where does it reside on the disk pack)
*> (ws)-prn-exit-print-88 only
03 (ws)-prn-sysout-file-name pic x(260).
*> A pointer to an OUTPUT Statement associated with this
*> SYSOUT Dataset. Points to the data structure contained
*> in IDADOUTP.CPY
*> (ws)-prn-exit-print-88 only
03 (ws)-prn-output-record-ptr pointer.