I know this has been asked a couple of times before, but please bear with me. I'd like to be able to run shell commands (system() or qx()) that time-out after a given time, something like: 
$exit = &command( "/bin/snore", 60 );

[download]
I pretty new to the world of pipe/fork/exec stuff, so please excuse any ignorance!

I fould this in perlipc: 
eval {
  local $SIG{ALRM} = sub { die "alarm clock restart" };
  alarm 10;
  flock(FH, 2);   # blocking write lock
  alarm 0;
};
if ($@ and $@ !~ /alarm clock restart/) { die }

[download]
Along with the quote:

           If the operation being timed out is system() or qx(), this technique is liable to generate zombies. If this matters to you, you'll need to do your own fork() and exec(), and kill the errant child process.

So after a bit of research i came up with this: 
#! /usr/bin/perl
use strict;

my $exit = &command( "sleep 4; exit 99;", 1 );

if(! defined( $exit ) ) { print "error: command timed-out\n" }
else                    { print "yay, it worked, exit: $exit\n" }

sub command
{
  my( $command, $timeout ) = @_;
  my $pid;
  
  eval
  {
    local $SIG{ALRM} = sub { die };
    
    if( $pid = fork ) { alarm $timeout }
    else              { exec( $command ) || die( "Couldn't exec $comma
+nd" ) }
    
    waitpid( $pid, 0 );
    alarm 0;
  };
  
  if( $@ ) { return undef    }
  else     { return $? / 256 }
}

[download]
  • fork... check
  • exec... check
  • kill... ? oops, where do i do this?

    Am i still breeding zombies? And how do i go about capturing output? Thanks.

    - ><iper


    my JAPH:
  print"Just another Perl hacker\n";
  #    ^ look, no space! pretty tricky hey?

    [download]

    In reply to The 'ol shell timeout question by xiper

    Title:
    Use:  <p> text here (a paragraph) </p>
    and:  <code> code here </code>
    to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.