perl function getprotobynumber

The getprotobynumber function in Perl is used to retrieve protocol information by number.

Here's an example of using getprotobynumber in Perl:

#!/usr/bin/perl

use strict;
use warnings;

# Get protocol information for protocol number 6 (TCP)
my $proto_info = getprotobynumber(6);

# Print the protocol name
print "Protocol name for number 6: $proto_info\n";

In this example, we call the getprotobynumber function to retrieve protocol information for protocol number 6 (which corresponds to TCP). The function returns a structure containing protocol information, including the protocol name. We then print the protocol name to the console using the print function.

When you run this script, it will print the protocol name for protocol number 6 to the console.

Note that the behavior of getprotobynumber may depend on the operating system and the specific protocol number being queried. Additionally, the function may return undef if the specified protocol number is not recognized by the system.