language-benchmarks/Interpreted/lev-distance-recursive/lev.pl

use List::Util 'min';

sub leven {
    my ($s, $t) = @_;

    return length($t) if $s eq '';
    return length($s) if $t eq '';

    my ($s1, $t1) = (substr($s, 1), substr($t, 1));

    (substr($s, 0, 1) eq substr($t, 0, 1))
      ? leven($s1, $t1)
      : 1 + min(
            leven($s1, $t1),
            leven($s, $t1),
            leven($s1, $t)
        );
}

print leven($ARGV[0], $ARGV[1]), "\n";