in reply to sigchild and $?

Is there a reason you don't use something like waitpid()?

FWIW, I've had -1 returned for $? in the past when I've set up SIGCHLD and then used perl's builtin fork/exec stuff (i.e. backticks, system(), qx()). I'm assuming perl (or the C library) sets up it's own waitpid() and/or sighandler for these expecting to reap the process and then I come along and screw things up with my SIGCHLD handler. Maybe someone with more wisdom can figure out how to do this right, but I tend to avoid setting up SIGCHLD and generally find that I don't need to.

bluto

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Re: Re: sigchild and $?
by Chapter_01 (Initiate) on Oct 01, 2003 at 13:03 UTC
    I would love to say I had a reason for not using waitpid(), but that might be a stretch. I will play around with that a bit. I did find a work around - if interested: 
    @ScriptMSG=`/run/some/script;/usr/echo "\$?"`;
chomp(@ScriptMSG);
$ExitCode=$ScriptMsg[$#ScriptMsg];

    [download]
    -Bryan
[reply]
[d/l]
      I wasn't thinking straight -- forget my comment about waitpid() which you would need if you did your own fork/exec. You don't need it with backticks. Basically backticks sets $? so you can check it directly (by using this code ripped from 'perldoc -f system'... 
      $exit_value  = $? >> 8;
$signal_num  = $? & 127;
$dumped_core = $? & 128;

      [download]
      bluto
[reply]
[d/l]

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