#!/usr/bin/perl
# Fig. 18.12: fig18_12.pl
# Using open to fork and filter output.

use warnings;
use strict;

$| = 1;

if ( my $pid = open( CHILD, "-|" ) ) {
   my $i;

   while ( <CHILD> ) {
      print( "Line ", ++$i, ": $_" );
   }

   close( CHILD ) or die( "Cannot close: $!" );
}
elsif ( defined( $pid ) ) {
   print( "I am doing some\n" );
   print( "processing here\n" );
   print( "that produces\n" );
   print( "multiple lines\n" );
   print( "of output.\n" );
   exit();
}
else {
   print( "Could not fork." );
}

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#  (C) Copyright 2001 by Deitel & Associates, Inc. and Prentice Hall.     #
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#  no warranty of any kind, expressed or implied, with regard to these    #
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