topic Re: PERL - question in Operating System - HP-UX

PERL - question

Anand_30 — Tue, 07 Jun 2005 16:20:18 GMT

Hi,

I used the following line in my PERL script to write the errors generated from a system command to a file "log"

system("/bin/cvs checkout -r$bra ivrsrc >>$log") || die "Cannot checkout CVS code from -r$bra";

But the messages from the system command is not written to the log file. It is instead appearing in the screen.

Can anyone please help.

Thanks,
Anand

Re: PERL - question

Rodney Hills — Tue, 07 Jun 2005 16:22:08 GMT

You need to redirect STDERR too.

system("/bin/cvs checkout -r$bra ivrsrc >>$log 2>&1")

HTH

-- Rod Hills

Re: PERL - question

Anand_30 — Tue, 07 Jun 2005 16:29:00 GMT

Hi Rod,

I tried it but does not seem to work. It does not print the messages on the STDERR now but does not write the messages to the log file either.

Thanks,
Anand

Re: PERL - question

Rodney Hills — Tue, 07 Jun 2005 16:31:49 GMT

Oops,

I forgot the "&" needs to be escaped...

system("/bin/cvs checkout -r$bra ivrsrc >>$log 2>\&1")

(Otherwise perl interprets it as a subroutine call)

-- Rod Hills

Re: PERL - question

Gopi Sekar — Wed, 08 Jun 2005 01:27:02 GMT

your problem is: CVS outputs the messages on standard error and >> will capture only standard output. To capture standard error you should use 2>.

Try this way:

system("/bin/cvs checkout -r$bra ivrsrc >>$log 2>>$log") || die "Cannot checkout CVS code from -r$bra";

Hope this helps,
Gopi

Re: PERL - question

Anand_30 — Wed, 08 Jun 2005 12:46:06 GMT

Hi Rod & Gopi,

Thanks for your help. But nothing seems to work.

I am trying it still now. The standard output seems to go to the log file but the standard error is getting displayed in the screen.

Thanks,
Anand

Re: PERL - question

harry d brown jr — Wed, 08 Jun 2005 13:24:19 GMT

You need to do something other than

system(...) || die ...;

Try something like this:

#!/usr/bin/perl
#
# this does not die:
#
system("echo hi mom >>/tmp/log 2>&1");
$errcode = $?;
printf("err code is ${errcode}\n");
eval ${errcode} == 0 || die "Cannot checkout CVS code from xyz";
#
# this DOES die:
#
system("NOREALCOMMAND hi mom >>/tmp/log 2>&1");
$errcode = $?;
printf("err code is ${errcode}\n");
eval ${errcode} == 0 || die "Cannot checkout CVS code from xyz";

live free or die
harry d brown jr

Re: PERL - question

harry d brown jr — Wed, 08 Jun 2005 13:29:27 GMT

Or better yet:

eval `/bin/cvs checkout -r${bra} ivrsrc >>${log} 2>&1` || die "Cannot checkout CVS code from -r${bra}";

live free or die
harry d brown jr

Re: PERL - question

harry d brown jr — Wed, 08 Jun 2005 13:41:08 GMT

I take back my last post. Use the system() ones I posted.

live free or die
harry d brown jr