See the current Perl documentation for IO::Pipe.
Here is our local, out-dated (pre-5.6) version:

IO::pipe - supply object methods for pipes

use IO::Pipe;
$pipe = new IO::Pipe;
if($pid = fork()) { # Parent
$pipe->reader();
while(<$pipe> {
....
}

IO::Pipe provides an interface to createing pipes between processes.
IO::Pipe, which is a reference to a newly created symbol (see the Symbol package). IO::Pipe::new optionally takes two arguments, which should be objects blessed into IO::Handle, or a subclass thereof. These two objects will be used for the system call
to pipe. If no arguments are given then method handles is called on the new IO::Pipe object.
These two handles are held in the array part of the
GLOB until either
reader or writer is called.
IO::Handle, and becomes a handle at the reading end of the pipe. If ARGS are given then fork
is called and ARGS are passed to exec.
IO::Handle, and becomes a handle at the writing end of the pipe. If ARGS are given then fork
is called and ARGS are passed to exec.
IO::Pipe::new
on the newly created IO::Pipe object. It returns an array of two objects blessed into IO::Pipe::End, or a subclass thereof.
Graham Barr <bodg@tiuk.ti.com>
Copyright (c) 1996 Graham Barr. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.