IO::Socket - Object interface to socket communications
use IO::Socket;
IO::Socket provides an object interface to creating and using sockets. It is built
upon the Handle interface and inherits all the methods defined by Handle.
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.
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.
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
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
&AF_INET will be returned.
&SOCK_STREAM will be returned.
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');
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
Graham Barr <Graham.Barr@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.
If rather than formatting bugs, you encounter substantive content errors in these documents, such as mistakes in the explanations or code, please use the perlbug utility included with the Perl distribution.