topic passing parameters to dcl procedures run as detached processes in Operating System - OpenVMS

passing parameters to dcl procedures run as detached processes

Jeff Bath — Sun, 14 Aug 2005 00:19:33 GMT

Is it possible to pass P1-P8 parameters when running a dcl procedure as a detached process?
When I create an empty command file and execute it I see that P1-P8 are defined.
This is how I am starting the procedure.
$ RUN SYS$SYSTEM:LOGINOUT.EXE -
/AUTHORIZE -
/DETACHED -
/INPUT=TESTDETACH.COM -
/PROCESS_NAME="TESTDETACH" -
/on=DEV2 -
/PRIOR=4 -
/OUTPUT=TESTDETACH.LOG -
/ERROR=TESTDETACH.ERR -

Re: passing parameters to dcl procedures run as detached processes

Volker Halle — Sun, 14 Aug 2005 02:11:28 GMT

Jeff,

no, this is not possible. There is special handling for parameters P1 to P8 and BATCH$RESTART in LOGINOUT and the CLI for BATCH processes only.

As another method to pass parameters to detached processes, you could use logical names (with DEFINE/CLUSTER if you want them to be available clusterwide as indicated by /on=DEV2 in your example).

Or you could write a temporary input file containing the parameters and the invocation of @TESTDETACH.COM p1 ... p8 and use this file as the /INPUT=... file.

Volker.

Re: passing parameters to dcl procedures run as detached processes

Jeff Bath — Sun, 14 Aug 2005 02:25:01 GMT

I actually to something similiar to the second example. I was looking to simplify the process a little. I played around with a mailbox but I figured that was just making things all little to complicated.

I don't think define/cluster works until VMS 8.2 or 8.3 we are using 7.3-2 so I need to do define/table=lnm$syscluster....

Thanks for the info.

Re: passing parameters to dcl procedures run as detached processes

Peter Quodling — Sun, 14 Aug 2005 21:26:59 GMT

IN one client environment, I routine use logicals as ways of passing parameters to an already operating batch job. (Actually web server netserver processes...)

Q

Re: passing parameters to dcl procedures run as detached processes

Phillip Thayer — Mon, 15 Aug 2005 09:16:04 GMT

Logical names would be the best bet although there are several differenct ways of passing the paramters. For example the .COM could be something like

$RUN PROGRAM.EXE
PARAMTER1-VALUE
PARAMETER2-VALUE
.
.
.
PARAMETERN-VALUE
$ rest of the .com file after this

Then the PROGRAM.EXE would simply use a read from the default input channel to get the values.

This is not the ideal way though. Logical names are best for passing small amounts of data between programs (1 - 256 bytes), Mailboxes are best for larger amounts of data (256-2048 bytes depending on your SYSGEN DEFMBXBUFQUO parameter value) and files are best for large blocks of data (>2048 bytes or the value of the SYSGEN DEFMBXBUFQUO value). Depending on the amount of data that you need to send in the p1-p8 type of parameter you should choose which method to use.

Phil

Re: passing parameters to dcl procedures run as detached processes

John Gillings — Mon, 15 Aug 2005 20:43:21 GMT

Jeff,

As others have explained, there is no direct mechanism for passing parameters into a command procedure executing in a detached process, but it's a very simple matter to create a jacket procedure to do it and then delete itself. Extending your example:

$ OPEN/WRITE jack JACKET.COM
$ WRITE jack "$ @TESTDETACH ""''p1'"" ""''p2'"" etc.."
$ WRITE jack "$ DELETE 'F$ENVIRONMENT(""PROCEDURE"")'"
$ CLOSE jack
$
$ RUN SYS$SYSTEM:LOGINOUT.EXE -
/AUTHORIZE -
/DETACHED -
/INPUT=JACKET.COM -
/PROCESS_NAME="TESTDETACH" -
/on=DEV2 -
/PRIOR=4 -
/OUTPUT=TESTDETACH.LOG -
/ERROR=TESTDETACH.ERR -
...