---
name: "IO::Socket::UNIX"
section: "3p"
platform: "openbsd"
package: "man"
version: "8.0-current-20261101"
release: "OpenBSD 8.0-current (2026-11-01)"
platforms: ["openbsd"]
url: "https://new.carta.tech/IO::Socket::UNIX"
---

# IO::Socket::UNIX(3p)

Object interface for AF\_UNIX domain sockets

## NAME

IO::Socket::UNIX - Object interface for AF\_UNIX domain sockets

## SYNOPSIS

```
    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
```

## DESCRIPTION

`"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.

## CONSTRUCTOR

- 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";
  ```

## METHODS

- **hostpath()**

  Returns the pathname to the fifo at the local end

- **peerpath()**

  Returns the pathanme to the fifo at the peer end

## SEE ALSO

Socket, IO::Socket

## AUTHOR

Graham Barr. Currently maintained by the Perl Porters.  Please report all bugs at \<https://github.com/Perl/perl5/issues\>.

## COPYRIGHT

Copyright (c) 1996-8 Graham Barr \<gbarr@pobox.com\>. All rights reserved. This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.