IO::Socket(3) 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
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IO::Socket(3) IO::Socket(3)
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
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IO::Socket(3) IO::Socket(3)
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
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IO::Socket(3) IO::Socket(3)
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.
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IO::Socket(3) IO::Socket(3)
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