my @letters = split(//, $string); my $i = 0; my @regexes; for (my $j = 0; $j < scalar(@letters); $j++) ( for (my $i = 0; $i < scalar(@letters); $k++) { if ($i != $j) { $regexes[$i] .= $letters[$j]; } else { $regexes[$i] .= '.{1}'; } } }