IO::Socket(3)
NNAAMMEE
IO::Socket - Object interface to socket communications
SSYYNNOOPPSSIISS
use IO::Socket;
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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.
CCOONNSSTTRRUUCCTTOORR
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.
MMEETTHHOODDSS
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.
SSUUBB--CCLLAASSSSEESS
IIOO::::SSoocckkeett::::IINNEETT
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');
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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
IIOO::::SSoocckkeett::::UUNNIIXX
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
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hostpath()
Returns the pathname to the fifo at the local end
peerpath()
Returns the pathanme to the fifo at the peer end
SSEEEE AALLSSOO
the Socket manpage, the IO::Handle manpage
AAUUTTHHOORR
Graham Barr lt;Graham.Barr@tiuk.ti.com
CCOOPPYYRRIIGGHHTT
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.