Perl listen Function



Description

This function configures the network socket SOCKET for listening to incoming network connections. Sets the incoming connection queue length to EXPR. You might want to consider using the IO::Socket module, which provides a much easier way of creating and listening to network sockets.

Syntax

Following is the simple syntax for this function −

listen SOCKET, EXPR

Return Value

This function returns 0 on failure and 1 on success.

Example

Following is the example code showing its basic usage, this is a server example alongwith socket implementation Perl Socket −

Perl Socket

#!/usr/bin/perl -w
# server.pl
#--------------------

use strict;
use Socket;

# use port 7890 as default
my $port = shift || 7890;
my $proto = getprotobyname('tcp');

# create a socket, make it reusable
socket(SOCKET, PF_INET, SOCK_STREAM, $proto) 
   or die "Can't open socket $!\n";
setsockopt(SOCKET, SOL_SOCKET, SO_REUSEADDR, 1) 
   or die "Can't set socket option to SO_REUSEADDR $!\n";

# bind to a port, then listen
bind( SOCKET, pack( 'Sn4x8', AF_INET, $port, "\0\0\0\0" ))
       or die "Can't bind to port $port! \n";
listen(SOCKET, 5) or die "listen: $!";
print "SERVER started on port $port\n";

# accepting a connection
my $client_addr;
while ($client_addr = accept(NET_SOCKET, SOCKET)) {
   # send them a message, close connection
   print NEW_SOCKET "Smile from the server";
   close NEW_SOCKET;
}
perl_function_references.htm
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