IO::Socket

IO::Socket(3)          Perl Programmers Reference Guide          IO::Socket(3)



NAME
       IO::Socket - Object interface to socket communications

SYNOPSIS
           use IO::Socket;


DESCRIPTION
       IO::Socket provides an object interface to creating and using sockets.
       It is built upon the the IO::Handle manpage interface and inherits all
       the methods defined by the IO::Handle manpage.

       IO::Socket only defines methods for those operations which are common
       to all types of socket. Operations which are specified to a socket in a
       particular domain have methods defined in sub classes of IO::Socket

       IO::Socket will export all functions (and constants) defined by the
       Socket manpage.

CONSTRUCTOR
       new ( [ARGS] )
           Creates an IO::Socket, which is a reference to a newly created
           symbol (see the Symbol package). new optionally takes arguments,
           these arguments are in key-value pairs.  new only looks for one key
           Domain which tells new which domain the socket will be in. All
           other arguments will be passed to the configuration method of the
           package for that domain, See below.

           IO::Sockets will be in autoflush mode after creation.  Note that
           versions of IO::Socket prior to 1.1603 (as shipped with Perl
           5.004_04) did not do this.   So if you need backward compatibility,
           you should set autoflush explicitly.

METHODS
       See the perlfunc manpage for complete descriptions of each of the
       following supported IO::Socket methods, which are just front ends for
       the corresponding built-in functions:

           socket
           socketpair
           bind
           listen
           accept
           send
           recv
           peername (getpeername)
           sockname (getsockname)

       Some methods take slightly different arguments to those defined in the
       perlfunc manpage in attempt to make the interface more flexible. These
       are

       accept([PKG])
           perform the system call accept on the socket and return a new
           object. The new object will be created in the same class as the
           listen socket, unless PKG is specified. This object can be used to
           communicate with the client that was trying to connect. In a scalar
           context the new socket is returned, or undef upon failure. In an
           array context a two-element array is returned containing the new
           socket and the peer address, the list will be empty upon failure.

           Additional methods that are provided are

       timeout([VAL])
           Set or get the timeout value associated with this socket. If called
           without any arguments then the current setting is returned. If
           called with an argument the current setting is changed and the
           previous value returned.

       sockopt(OPT [, VAL])
           Unified method to both set and get options in the SOL_SOCKET level.
           If called with one argument then getsockopt is called, otherwise
           setsockopt is called.

       sockdomain
           Returns the numerical number for the socket domain type. For
           example, for a AF_INET socket the value of &AF_INET will be
           returned.

       socktype
           Returns the numerical number for the socket type. For example, for
           a SOCK_STREAM socket the value of &SOCK_STREAM will be returned.

       protocol
           Returns the numerical number for the protocol being used on the
           socket, if known. If the protocol is unknown, as with an AF_UNIX
           socket, zero is returned.

SUB-CLASSES
       IO::Socket::INET

       IO::Socket::INET provides a constructor to create an AF_INET domain
       socket and some related methods. The constructor can take the following
       options

           PeerAddr    Remote host address          <hostname>[:<port>]
           PeerPort    Remote port or service       <service>[(<no>)] ⎪ <no>
           LocalAddr   Local host bind address      hostname[:port]
           LocalPort   Local host bind port         <service>[(<no>)] ⎪ <no>
           Proto       Protocol name (or number)    "tcp" ⎪ "udp" ⎪ ...
           Type        Socket type                  SOCK_STREAM ⎪ SOCK_DGRAM ⎪ ...
           Listen      Queue size for listen
           Reuse       Set SO_REUSEADDR before binding
           Timeout     Timeout value for various operations

       If Listen is defined then a listen socket is created, else if the
       socket type, which is derived from the protocol, is SOCK_STREAM then
       connect() is called.

       The PeerAddr can be a hostname or the IP-address on the "xx.xx.xx.xx"
       form.  The PeerPort can be a number or a symbolic service name.  The
       service name might be followed by a number in parenthesis which is used
       if the service is not known by the system.  The PeerPort specification
       can also be embedded in the PeerAddr by preceding it with a ":".

       If Proto is not given and you specify a symbolic PeerPort port, then
       the constructor will try to derive Proto from the service name.  As a
       last resort Proto "tcp" is assumed.  The Type parameter will be deduced
       from Proto if not specified.

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

       Examples:

          $sock = IO::Socket::INET->new(PeerAddr => 'www.perl.org',
                                        PeerPort => 'http(80)',
                                        Proto    => 'tcp');

          $sock = IO::Socket::INET->new(PeerAddr => 'localhost:smtp(25)');

          $sock = IO::Socket::INET->new(Listen    => 5,
                                        LocalAddr => 'localhost',
                                        LocalPort => 9000,
                                        Proto     => 'tcp');

          $sock = IO::Socket::INET->new('127.0.0.1:25');


       METHODS

       sockaddr ()
           Return the address part of the sockaddr structure for the socket

       sockport ()
           Return the port number that the socket is using on the local host

       sockhost ()
           Return the address part of the sockaddr structure for the socket in
           a text form xx.xx.xx.xx

       peeraddr ()
           Return the address part of the sockaddr structure for the socket on
           the peer host

       peerport ()
           Return the port number for the socket on the peer host.

       peerhost ()
           Return the address part of the sockaddr structure for the socket on
           the peer host in a text form xx.xx.xx.xx

       IO::Socket::UNIX

       IO::Socket::UNIX provides a constructor to create an AF_UNIX domain
       socket and some related methods. The constructor can take the following
       options

           Type        Type of socket (eg SOCK_STREAM or SOCK_DGRAM)
           Local       Path to local fifo
           Peer        Path to peer fifo
           Listen      Create a listen socket


       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
       the Socket manpage, the IO::Handle manpage

AUTHOR
       Graham Barr <Graham.Barr@tiuk.ti.com>

COPYRIGHT
       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.

































3rd Berkeley Distribution    perl 5.005, patch 02                IO::Socket(3)