perl function getsockname

The getsockname function is a built-in Perl function that is used to retrieve the local address of a socket. It takes a socket file descriptor as its argument and returns an array containing the local address information.

Here's an example that demonstrates how to use getsockname:

#!/usr/bin/perl

use strict;
use warnings;
use Socket;

# Create a socket
socket(SOCK, PF_INET, SOCK_STREAM, getprotobyname('tcp'));

# Bind the socket to a local address and port
bind(SOCK, sockaddr_in(0, inet_aton('127.0.0.1')));

# Get the local address of the socket
my $local_addr = getsockname(SOCK);

# Print the local address information
my ($port, $addr) = sockaddr_in($local_addr);
print "Local Address: " . inet_ntoa($addr) . "\n";
print "Local Port: " . $port . "\n";

# Close the socket
close(SOCK);

In this example, we create a socket using the socket function and bind it to a local address and port using the bind function. We then call getsockname to retrieve the local address information and assign the returned array to the variable $local_addr. We extract the port number and address from the array using the sockaddr_in function and then convert the address to a human-readable format using inet_ntoa. Finally, we print the local address information.

Note that we need to include the Socket module in order to use the sockaddr_in and inet_aton functions, which are used to manipulate socket addresses.