The IO::Socket Module

The IO::Socket module included in the core Perl distribution provides an object-oriented approach to socket programming. This module provides a convenient way to handle the large number of options you have to deal with, and it handles the laborious task of forming addresses. IO::Socket is built upon the Socket module provided in the standard library. It inherits from IO::Handle, which supports a class of filehandle objects for much of the IO library. The following IO::Socket functions are simply frontends for the corresponding built-in functions and use the same syntax:

socket
socketpair
bind
listen
send
recv
peername (same as getpeername)
sockname (same as getsockname)

The accept function in IO::Socket is slightly different from the equivalent function, however, and is described later in the chapter.

IO:Socket contains two subclasses: INET and UNIX. The INET subclass is used to create and manipulate Internet-domain sockets, such as the ones used in the examples. The UNIX subclass creates Unix domain sockets.

Client-Side Sockets

IO::Socket greatly simplifies the implementation of a socket for client communications. The following example creates an Internet-domain socket (using the INET subclass) and attempts to connect to the specified server:

use IO::Socket;
$sock = new IO::Socket::INET (PeerAddr => 'www.ora.com',
                              PeerPort => 80,
                              Proto    => 'tcp');
die "$!" unless $sock;

IO::Socket::INET::new creates an object containing a socket filehandle and connects it ...

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