#!/usr/bin/perl

use strict;
use warnings;

use POSIX ':fcntl_h';
use IPC::Run 'run';

my $fifo = "test_fifo";

unless ( -p $fifo ) {
  system("mkfifo", $fifo) == 0 or die "Unable to create FIFO: $!";
  }

  # FIFOs need readers before writers.
  sysopen FIFO_OUT, $fifo, O_RDONLY | O_NONBLOCK or die "Unable to open FIFO for read: $!";
  sysopen FIFO_IN,  $fifo, O_WRONLY | O_NONBLOCK or die "Unable to open FIFO for write: $!";

  run ( ["cat", "pipe.pl"], ">", \*FIFO_IN, "<", \*FIFO_OUT );

  while (<FIFO_OUT>) {
    chomp;
    print "Foo: ", $_, ": Bar.\n";
  }

      close FIFO_IN  or die "Problems closing FIFO writer: $!";
      close FIFO_OUT or die "Problems closing FIFO reader: $!";