IO::Socket
Section: Perl Programmers Reference Guide (3)
Updated: perl 5.005, patch 02
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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.
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- CONSTRUCTOR
-
- METHODS
-
- SUB-CLASSES
-
- IO::Socket::INET
-
- METHODS
-
- IO::Socket::UNIX
-
- METHODS
-
- SEE ALSO
-
- AUTHOR
-
- COPYRIGHT
-
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Time: 15:39:57 GMT, July 31, 2024