MAN page from Old RedHat 5.X perl-5.004-4.i386.rpm

IO::Socket

Section: Perl Programmers Reference Guide (3)
Updated: perl 5.004, patch 04
Index

NAME

IO::Socket - Object interface to socket communications

SYNOPSIS

    use IO::Socket;

DESCRIPTION

IO::Socket provides an object interface to creating and using sockets. Itis built upon the the IO::Handle manpage interface and inherits all the methods definedby the IO::Handle manpage.

IO::Socket only defines methods for those operations which are common to alltypes 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 anewly created symbol (see the Symbol package). newoptionally takes arguments, these arguments are in key-value pairs.new only looks for one key Domain which tells new which domainthe socket will be in. All other arguments will be passed to theconfiguration method of the package for that domain, See below.
IO::Sockets will be in autoflush mode after creation. Note thatversions 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 shouldset autoflush explicitly.

METHODS

See the perlfunc manpage for complete descriptions of each of the followingsupported IO::Socket methods, which are just front ends for thecorresponding 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 manpagein attempt to make the interface more flexible. These are

accept([PKG]): perform the system call accept on the socket and return a new object. Thenew object will be created in the same class as the listen socket, unlessPKG is specified. This object can be used to communicate with the clientthat 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 returnedcontaining the new socket and the peer address, the list willbe empty upon failure.
Additional methods that are provided are
timeout([VAL]): Set or get the timeout value associated with this socket. If called withoutany arguments then the current setting is returned. If called with an argumentthe 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 calledwith one argument then getsockopt is called, otherwise setsockopt is called.
sockdomain: Returns the numerical number for the socket domain type. For example, fora AF_INET socket the value of &AF_INET will be returned.
socktype: Returns the numerical number for the socket type. For example, fora SOCK_STREAM socket the value of &SOCK_STREAM will be returned.
protocol: Returns the numerical number for the protocol being used on the socket, ifknown. If the protocol is unknown, as with an AF_UNIX socket, zerois returned.

SUB-CLASSES

IO::Socket::INET

IO::Socket::INET provides a constructor to create an AF_INET domain socketand 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 thesocket type, which is derived from the protocol, is SOCK_STREAM thenconnect() 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 symbolicservice name. The service name might be followed by a number inparenthesis which is used if the service is not known by the system.The PeerPort specification can also be embedded in the PeerAddrby 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 servicename. As a last resort Proto ``tcp'' is assumed. The Typeparameter will be deduced from Proto if not specified.

If the constructor is only passed a single argument, it is assumed tobe 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 atext form xx.xx.xx.xx
peeraddr (): Return the address part of the sockaddr structure for the socket onthe 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 thepeer host in a text form xx.xx.xx.xx

IO::Socket::UNIX

IO::Socket::UNIX provides a constructor to create an AF_UNIX domain socketand 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

AUTHOR

Graham Barr <Graham.BarrAATTtiuk.ti.com>

COPYRIGHT

This document was created byman2html,using the manual pages.

IO::Socket

NAME

SYNOPSIS

DESCRIPTION

CONSTRUCTOR

METHODS

SUB-CLASSES

IO::Socket::INET

METHODS

IO::Socket::UNIX

METHODS

SEE ALSO

AUTHOR

COPYRIGHT

Index