Perl script unix cshell: running external app.

Hi Guys,

Thanks for your replies.  I have some comments for both of you below.

@ahoffmann:
I have copied and pasted the code you gave, however it doesnt seem to get anything building.
Output is as follows:
-----------------------------------------------------
com>
com>build.script dflt_image .test

Your request is being processed...

---------- Build Summary ----------
        Image:  unix-p-ms
        Suffix: .test
        Status: 0
-----------------------------------

Sending output to nohup.out

---------- Build Summary ----------
        Image:  unix-p-ms
        Suffix: .test
        Status: 4297
-----------------------------------
com>
com>
-----------------------------------------------------
So a few points to note about the above output is that firstly the "build summary" does display more than once althoug it only appears in the code once [and not in any loops either :-) ].
The second thing is that right after the "Sending output to nohup.out" is displayed there is about a 10 second pause before the 2nd build summary is displayed.  I also see that the build.log file is not created.
Any ideas?


@stefan73:
You're method worked and kicked off a build as well as redirecting the output to the correct file.  The only small
issue is that I'm not able to get the process ID, instead the output displays the entire command.  Would you know
how I can get this easily (without having to trawl through "ps -ef" if possible) ?


Thanks for your help.

stefan73, good eyes, missed to correct the csh syntax
please correct $cmd as follows:

$cmd = "nohup make MAKEFLAG_J='-j20 -l10' BIN_SUFFIX=$SUFFIX $IMAGE > build.log 2>&1 &";

Thanks - didnt think of mixing both of your suggestions, so I now have:
==============================
$cmd = "nohup make MAKEFLAG_J='-j20 -l10' BIN_SUFFIX=$SUFFIX $IMAGE > build.log 2>&1 &";
$PID=fork();
system($cmd) if ($PID>0);

#$PID = qq[nohup make MAKEFLAG_J="-j20 -l20" BIN_SUFFIX=$SUFFIX $IMAGE > build.log 2>&1 &];
#system($PID);

print "\n---------- Build Summary ----------";
print "\n\tImage:  $IMAGE\n\tSuffix: $SUFFIX";
print "\n\tStatus: $PID";
print "\n-----------------------------------\n\n";
==============================

This works but still has a problem that the build summary is displayed twice (possibly due to the fork()?)
/shamrahm-sa57779_8t>~/perl.script unix-p-ms .test
Outuput:
com>
com>build.script dflt_image .test

Your request is being processed...

---------- Build Summary ----------
        Image: dflt_image
        Suffix: .test
        Status: 0
-----------------------------------


---------- Build Summary ----------
        Image: dflt_image
        Suffix: .test
        Status: 23293
-----------------------------------
com>

So above, I would only need the second build summary since the first provies no real information (i.e the pid).
Is it possible to stop this bit of code being run twice?

Thanks.

change as follows:

$PID=fork();
if ($PID>0){
  exec($CMD);
  exit 0;
} else {
print "\n---------- Build Summary ----------";
print "\n\tImage:  $IMAGE\n\tSuffix: $SUFFIX";
print "\n\tStatus: $PID";
print "\n-----------------------------------\n\n";
}


but keep in mind that your "Build Summaryy just reports the child's PID, and not if the command succeds or what result it produced.

>  Why bother with a Perl script.
'cause the questioner makes exercises ;-)

But I prefer too:  KISS - keep it simple stupid

There are a number of reasons I've chosen to use perl, I originally did what is shown above using csh.  The three main reasons that I decided to change to perl were:
1. I wanted to start learning perl again (I had a tiny bit of experience a long time ago).
2. The small bit of code above is only a part of the overall functionality that I'm developing, so I believed perl would offer me the greatest flexibility for doing the things I need, and I may also find help easily for when I get stuck.
3. The unix environment the script will be used it is mixed, so people are using different shells, like bash etc.

I will increase the points for this question and then split them between you.
Thanks to all of you for resonding and helping :-)