open(FH, "dir|")
  or die "Couldn't run dir: $!\n";

##</code><code>##

#!/usr/bin/perl

defined ($pid = open $fh, "-|") or warn $! and last;
if ($pid)
{
  # Parent
  while (<$fh>)
  {
    print "OUTPUT: $_";
  }
}
else
{
  # Child
  exec("/bin/ls");
}