#foo() is the sub that outputs a lot of data
  my $pid = open(SUBOUT, '-|');
  defined($pid) or die "Fork failed: $!";
  if ($pid == 0) { 
    $|=1; foo(); exit(0);
  }
  while (<SUBOUT>) ...

##</code><code>##

#!/usr/bin/perl -l
defined($tmp = open(FOO, '-|')) or die "Can't fork: $!";

if ($tmp==0) {
        print "Roses are red\nViolets are blue\nI think Perl rules\nAnd you should too\n";
        exit(1);
}

print for map {chomp; "[$tmp] {$_}"} <FOO>;

##</code><code>##

$"=$,,$_=q>|\p4<6 8p<M/_|<('=>
.q>.<4-KI<l|2$<6%s!<qn#F<>;$,
.=pack'N*',"@{[unpack'C*',$_]
}"for split/</;$_=$,,y[A-Z a-z]
         {}cd;print lc