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 IO::Handle interface
and inherits all the methods defined by IO::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 Socket.

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 con
figuration method of the package for that domain, See
below.

NOTE NOTE NOTE NOTE NOTE NOTE NOTE NOTE NOTE NOTE

NOTE NOTE; As of VERSION 1.18 all IO::Socket objects have aut
oflush turned on by default. This was not the case
with earlier releases.

NOTE NOTE NOTE NOTE NOTE NOTE NOTE NOTE NOTE NOTE

NOTE NOTE

METHODS

See perlfunc for complete descriptions of each of the fol lowing 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)
shutdown
Some methods take slightly different arguments to those defined in perlfunc 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 a list context a two-element
array is returned containing the new socket and the
peer address; the list will be empty upon failure.; The timeout in the [PKG] can be specified as zero to
effect a "poll", but you shouldn't do that because a
new IO::Select object will be created behind the
scenes just to do the single poll. This is horren
dously inefficient. Use rather true select() with a zero timeout on the handle, or non-blocking IO.
socketpair(DOMAIN, TYPE, PROTOCOL): Call "socketpair" and return a list of two sockets
created, or an empty list on failure.
Additional methods that are provided are:
atmark: True if the socket is currently positioned at the
urgent data mark, false otherwise.

use IO::Socket;

my $sock = IO::Socket::INET->new('some_server');
$sock->read(1024,$data) until $sock->atmark;; Note: this is a reasonably new addition to the family
of socket functions, so all systems may not support
this yet. If it is unsupported by the system, an
attempt to use this method will abort the program.; The atmark() functionality is also exportable as sock_ atmark() function:

use IO::Socket 'sockatmark';
This allows for a more traditional use of sockatmark() as a procedural socket function. If your system does not support sockatmark(), the "use" declaration will fail at compile time.
connected: If the socket is in a connected state the the peer
address is returned. If the socket is not in a con
nected state then undef 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.
sockdomain: Returns the numerical number for the socket domain
type. For example, for an AF_INET socket the value of
&AF_INET will be 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.
socktype: Returns the numerical number for the socket type. For
example, for a SOCK_STREAM socket the value of
&SOCK_STREAM will be returned.
timeout([VAL]): Set or get the timeout value associated with this
socket. If called without any arguments then the cur
rent setting is returned. If called with an argument
the current setting is changed and the previous value
returned.

AUTHOR

Graham Barr. atmark() by Lincoln Stein. Currently main tained by the Perl Porters. Please report all bugs to
<perl5-porters@perl.org>.

COPYRIGHT

The atmark() implementation: Copyright 2001, Lincoln Stein <lstein@cshl.org>. This module is distributed under the
same terms as Perl itself. Feel free to use, modify and
redistribute it as long as you retain the correct attribu
tion.

docs.sk

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