Perl listen Function

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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;
}

When above code is executed, it produced following result




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