#!/usr/bin/env perl

use strict;
use warnings;
use List::Util qw(zip);

my $str1='LFGSLSIIVAHHM';
my $str2='LFGSLSIIVSHHM';

my ($s1len, $s2len) = map {length} ($str1, $str2);
die "Length mismatch: $str1 ($s1len) != $str2 ($s2len).\n"
    if $s1len != $s2len;

my $match = grep {$_->[0] eq $_->[1]}
            zip [split //, $str1], [split //, $str2];
my $mismatch = $s1len-$match;

print "Matches: $match\nMismatches: $mismatch\nPercent match: ",
      sprintf("%.01f", ($match / $s1len) * 100),
      "\n";