in reply to Re: undefined question
in thread undefined question

Thanks dws. Also informative. ONe thing though: I needed to make a small change. 
while ( my $proc = <PROCS> ) {
      ...
      $found_one = 1;
  }
  if ( $found_one ) {
      print "looks okay here\n";
      found_one = 0;
  } else {
      print "couldn't find $process\n";
  }

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W/o resetting the $found_one to 0, it would never alert me when the other processes (anything after 1) weren't running. As for the greps externally - I recall finding this in a perl tutorial many moons ago, and never learned it another way. Might you have a link that explains it internally?

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Re: Re: Re: undefined question
by dws (Chancellor) on Jun 09, 2003 at 04:58 UTC
    As for the greps externally - I recall finding this in a perl tutorial many moons ago, and never learned it another way. Might you have a link that explains it internally?

    You'd find that described under "regular expressions". As an example, 

      open(PROCS, "ps -a | grep $process |");
  while ( my $proc = <PROCS> ) {
      # ...
  }

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    can be rewriten (assuming $process holds an alphanumeric string) as 
      open(PROCS, "ps -a |");
  while ( my $proc = <PROCS> ) {
      next if $proc !~ /$process/;
      # ...
  }

    [download]
    Regular expressions are your friends. Learning about them pays off in many ways.

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[d/l]
[select]
      I've actaully been playing w/ regular expressions a bit lately. I wouldn't have thoght of using them w/ this though - this is pretty easy, after I got over my initial hurdle. They're still a bit foreign, but after reading (and asking) here, I've gotten them to do some pretty helpful things. Again - thanks for the wisdom
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