topic help with dcl script in Operating System - OpenVMS

help with dcl script

sandyt — Sun, 09 Dec 2007 09:44:10 GMT

I need some help writing a dcl script to run on a alpha vmx 7.3-2.

The script needs to wake up every 5 minutes and check if file a.a exists. If it does exist, the script needs to do x, y ,z and then go to sleep again.

I don't know if it would be best (system overhead) just to keep the script active, or have a batch job that re-submits itself every interval.

Thanks for the help.

Any replys

Re: help with dcl script

Jan van den Ende — Sun, 09 Dec 2007 10:12:39 GMT

sandyt,

>>>
I don't know if it would be best (system overhead) just to keep the script active, or have a batch job that re-submits itself every interval.
<<<

Usual answer to such questions: "it depends"
In a cluster, maybe you want failover capability?

But, as a general rule, a "WAIT" in VMS consumes ZERO, where batch recurring jobs DO have their termination processing, and the next job's startup processing.

Bsaed upon cycling through WAIT:

$ ! infinitely looping process
$loop:
$ if f$search("absolute_dir_spec:A.A") .nes. ""
$ then
$
$
$
$
$ endif
$ wait 0:5
$ goto loop

-- You will have to fill in x, y, and z processing
-- You will have to take care that this A.A is not found again in the next loop
-- I _STRONGLY_ advise to use full-path file specification for (preferably via Concealed Device namings) and avoid/remove any dependency on any value of SET DEFAULT.

Success.

Proost.

Have one on me.

jpe

Re: help with dcl script

sandyt — Sun, 09 Dec 2007 10:43:00 GMT

Thanks for the quick reply and example.