Sys::Net - system network information or actions

	my %if_named = %{Sys::Net::interfaces()};
	foreach my $if_name (keys %if_named) {
		print 'interface with name: ', $if_name, ' has ip: ', $if_named{$if_name}, "\n";
	}

	use Sys::Net 'resolv';
	my $hostname = resolv('127.0.0.1');
	my $ip       = resolv('localhost');

	our @EXPORT_OK = qw(resolv interfaces);

	{
		'lo'   => { 'ip' => '127.0.0.1'     },
		'eth0' => { 'ip' => '192.168.100.6' },
	};

package Sys::Net;

use warnings;
use strict;

our $VERSION = '0.06';

use Socket 'inet_ntoa', 'inet_aton', 'AF_INET';

use base 'Exporter';

our $IFCONFIG_CMD = '/sbin/ifconfig';
our $if_named;
our @EXPORT_OK = qw(resolv interfaces);

sub interfaces {
	return $if_named
		if defined $if_named;

	$if_named = {};

	# TODO use File::Which to look if there is ifconfig (also any more folders then just one)	
	my @ifconfig_out = `$IFCONFIG_CMD`;
	
	my $ifname;
	my $ifip;
	foreach my $line (@ifconfig_out) {
		# empty line resets the values
		if ($line =~ /^\s*$/) {
			$ifname = undef;
			$ifip   = undef;
		}

		# get columns 1, 2, 3
		my ($c1,$c2,$c3) = split /\s+/, $line;

		# get interface name
		$ifname = $c1
			if $c2 eq 'Link';
		# get ip address
		($ifip) = $c3 =~ m/addr:(.+)/
			if $c2 eq 'inet';
		
		# if we have both ip and interface name store it
		$if_named->{$ifname} = { 'ip' => $ifip }
			if ($ifname and $ifip);
	}
	
	return $if_named;
}

sub resolv {
	my $name = shift;
	
	# resolv ip to a hostname
	if ($name =~ m/^\s*[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\s*$/) {
		return scalar gethostbyaddr(inet_aton($name), AF_INET);
	}
	# resolv hostname to ip
	else {
		return inet_ntoa(scalar gethostbyname($name));
	}
}


1;


__END__