IO::Socket

Section: Perl Programmers Reference Guide (3perl)
Updated: 2001-03-03
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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 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 configuration method of the package for that domain, See below.

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

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METHODS

See perlfunc 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)
    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.
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:

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.
connected: If the socket is in a connected state the the peer address is returned. If the socket is not in a connected state then undef will be returned.

AUTHOR

Graham Barr. Currently maintained by the Perl Porters. Please report all bugs to <perl5-porters@perl.org>.

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Time: 22:21:00 GMT, December 09, 2024