leonidlm has asked for the wisdom of the Perl Monks concerning the following question:

Hi All,
Just a small question. I am using the following code: 
    eval {
        local $SIG{ALRM} = sub {die "Cant get node's time ($host)\n"};
        alarm 5;
        @out = qx {$cmd};
        
        if ($out[1] !~ /OVO Managed Node status :/) {
            print "Detected error for node $host\n";
        }
        alarm 0;
        
    };

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My problem is that if in one iteration the timeout really worked the process run by qx is still will be running in the background! Is there a way of killing this process too right after the eval will finish?

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Re: eval leaving processess behind
by ikegami (Patriarch) on Nov 09, 2008 at 17:07 UTC 
        my $cmd = ...;

    my $pid;
    my $fh;
    my @out;
    eval {
        local $SIG{ALRM} = sub { die "Timeout\n" };
        alarm 5;
        $pid = open($fh, '-|', $cmd)
           or die;
        @out = <$fh>;
        undef $fh;
        alarm 0;
    };
    kill TERM => $pid if defined($fh);

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[reply]
[d/l]
      Very nice, thank you.
      But is there a more "elegant way" of doing this ? In your solution I will fork another perl instance for each task, I am not sure it is the most efficient solution.
[reply]

        q{perl -e'sleep 60*60'} was just the command I used for testing. You'd continue to use the same command as before. I've altered the post execute $cmd as your snippet did.

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