I don't know if has been mentioned -- I admit I have kind of tuned out as this thread has dragged on -- but it may be relevant to Gils' conjecture to note that PARMDD is quite analogous to the OPTFILE option of the XL C/C++ and Enterprise COBOL compilers, both of which are "roll your own" solutions by the compiler writers to the constraints of the 100-byte limitation on PARM=.
For those unfamiliar with the option, both compilers offer the user the ability to specify PARM='FOO,OPTFILE,BAR' whereupon the contents of DD SYSOPTF are logically inserted into the PARM= string between FOO and BAR. C offers slightly more flexibility in that one may code OPTFILE(filespec) and avoid the tyranny of DD SYSOPTF, and even allowing the contents of multiple, different files to be logically inserted at different spots in the PARM= string. Charles -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Paul Gilmartin Sent: Sunday, April 07, 2013 10:58 AM To: [email protected] Subject: More PARMDD: Processing sequence? More questions keep occurring to me. When is the data set associated with PARMDD read? o Is it early enough in processing that: // SET DSNAME=MY.DATA.SET //UNAUTH EXEC PGM=MYPGM,PARMDD=PARMS //PARMS DD *,SYMBOLS=(JCL) // ... &DSNAME ... ... can be effective? o Is it late enough in processing that PARMDD can refer to a temporary data set passed from an earlier job step? (Are both even logically possible?) o In the absence of SYMBOLS=JCL, or if PARMDD is a data set external to the job's JCL, will symbol references appearing in that data set be resolved by JCL processing? Questions such as above impel me to wonder, why was PARMDD introduced, rather than simply allowing a longer PARM= string? This might be continued over 585 lines, if necessary to accommodate 32760 characters, possibly read from JCLLIB. But the facility to access the PARM from an external file may have its own peculiar added value. ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
