IO::Socket::UNIX - Object interface for AF_UNIX domain sockets


    use IO::Socket::UNIX;

    my $SOCK_PATH = "$ENV{HOME}/unix-domain-socket-test.sock";

    # Server:
    my $server = IO::Socket::UNIX->new(
        Type => SOCK_STREAM(),
        Local => $SOCK_PATH,
        Listen => 1,

    my $count = 1;
    while (my $conn = $server->accept()) {
        $conn->print("Hello " . ($count++) . "\n");

    # Client:
    my $client = IO::Socket::UNIX->new(
        Type => SOCK_STREAM(),
        Peer => $SOCK_PATH,

    # Now read and write from $client


IO::Socket::UNIX provides an object interface to creating and using sockets in the AF_UNIX domain. It is built upon the IO::Socket interface and inherits all the methods defined by IO::Socket.


new ( [ARGS] )

Creates an IO::Socket::UNIX object, which is a reference to a newly created symbol (see the Symbol package). new optionally takes arguments, these arguments are in key-value pairs.

In addition to the key-value pairs accepted by IO::Socket, IO::Socket::UNIX provides.

    Type        Type of socket (eg SOCK_STREAM or SOCK_DGRAM)
    Local       Path to local fifo
    Peer        Path to peer fifo
    Listen      Queue size for listen

If the constructor is only passed a single argument, it is assumed to be a Peer specification.

If the Listen argument is given, but false, the queue size will be set to 5.

If the constructor fails it will return undef and set the $IO::Socket::errstr package variable to contain an error message.

    $sock = IO::Socket::UNIX->new(...)
        or die "Cannot create socket - $IO::Socket::errstr\n";

For legacy reasons the error message is also set into the global $@ variable, and you may still find older code which looks here instead.

    $sock = IO::Socket::UNIX->new(...)
        or die "Cannot create socket - $@\n";



Returns the pathname to the fifo at the local end


Returns the pathanme to the fifo at the peer end


Socket, IO::Socket


Graham Barr. Currently maintained by the Perl Porters. Please report all bugs at


Copyright (c) 1996-8 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.