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

Hi, I am trying to use this one liner in a perl script with back tags (`) 
$echo=`alarm() { /bin/perl -e "alarm shift; exec  @ARGV " '$@'; } ;ala
+rm 4 " while [ 1 ]; do echo ' ' ;done "`;
print "$echo";

[download]
But it doesnt seem to be working. Can you help me run that line from a script instead of a command line. Thank you

Replies are listed 'Best First'.
Re: one liner in script
by choroba (Cardinal) on Apr 12, 2010 at 14:08 UTC
    Can you please specify what the script should do, according to your intentions?
[reply]
      Actually I have a much larger perl script where I run a bunch of commands from the command line in between back tacs like 
      $line=`cmd 1; cmd 2 ; cmd 3 .... cmd n `;

      [download]
      Now for one of the commands I have to run it for only 4 secs. Now the only way I could come up with is like this : alarm() { /bin/perl -e 'alarm shift; exec @ARGV' "$@"; } ;alarm 4 'cmd 4 ' Now when I try to put that in a perl script between back tacs it doesnt work. This code doesnt work. 
      $line=`cmd 1; cmd 2 ; cmd 3 ;alarm() { /bin/perl -e 'alarm shift; exec
+ @ARGV' "$@"; } ;alarm 4 'cmd 4 '.... cmd n `;

      [download]
      Is there anyway I can make the cmd 4 run for 4 secs only.
[reply]
[d/l]
[select]
        This code works for me: 
        $line=`
  cmd 1
  cmd 2
  cmd 3
  alarm () {
    /usr/bin/perl -e '
      alarm shift;
      exec \@ARGV;' -- "\$@"
  }
  alarm 4 cmd 4
  cmd n `;

print "$line";

        [download]
        The differences are:
        1. path to perl (might be different on your system)
        2. escaping the @ sign
        3. escaping the $ sign
        4. Update: the -- separator
[reply]
[d/l]

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