debian-version

#!/usr/bin/env perl

use IO::File;
use strict;
use warnings;

my $versionFile = '/etc/debian_version';

my %rxMap = (
	1.1 => 'Buzz',
	1.2 => 'Rex',
	1.3 => 'Bo',
	2.0 => 'Hamm',
	2.1 => 'Slink',
	2.2 => 'Potato',
	3.0 => 'Woody',
	3.1 => 'Sarge',
	4.0 => 'Etch',
	5.0 => 'Lenny',
	6.0 => 'Squeeze',
	7 => 'Wheezy',
	8 => 'Jessie',
	9 => 'Stretch',
	10 => 'Buster',
	11 => 'Bullseye',
	12 => 'Bookworm',
	13 => 'Trixie',
);

sub ver {
	my ($file) = @_;

	my $actualVersion = '';
	my $fh = IO::File->new($file, 'r');
	if (defined($fh)) {
		$actualVersion = <$fh>;
		chomp($actualVersion);
	} else {
		return 'error';
	}

	if ($actualVersion) {
		while (my ($ver, $codename) = each(%rxMap)) {
			my $rx = qr/^$ver/;
			if ($actualVersion =~ $rx) {
				return $codename;
			}
		}
	}

	return 'unknown';
}

sub main {
	my $codename = ver($versionFile);
	printf("%s\n", $codename);

	if ($codename eq 'unknown' || $codename eq 'error') {
		return 1;
	}

	return 0;
}

exit(main());