perl function gethostbyname

The gethostbyname function in Perl is used to retrieve information about a specific host, identified by its name.

Here's an example of using gethostbyname in Perl:

#!/usr/bin/perl

use strict;
use warnings;
use Socket;

# Name of the host we want to look up
my $hostname = "www.example.com";

# Look up the host information by name
my $host_info = gethostbyname($hostname);

if (!$host_info) {
    die "Host $hostname not found";
}

# Convert the IP address from binary to dotted-quad format
my $ip_address = inet_ntoa($host_info);

# Print the host information
print "IP Address: $ip_address\n";

In this example, we use the gethostbyname function to retrieve information about the host named "www.example.com". If the host is not found, we exit with an error message.

If the host is found, we convert its IP address from binary to dotted-quad format using the inet_ntoa function from the Socket module, and print it to the console.

When you run this script, it will print the IP address of the host named "www.example.com" to the console, assuming that such a host exists and can be looked up. If the host is not found, the script will exit with an error message.

Note that gethostbyname performs a DNS lookup to retrieve the host information, so it requires appropriate DNS resolution to be configured on the system. If DNS resolution is not available, or if the host does not have a valid DNS entry, this function may not be able to retrieve the host information.