>perl -wMstrict -le "my $str = 'ABC---DR----EEEEEGGGG-GRE-RED----KKKK---'; print qq{'$str'}; my $len = $str =~ tr/A-Za-z//; print qq{'$str'}; print $len; " 'ABC---DR----EEEEEGGGG-GRE-RED----KKKK---' 'ABC---DR----EEEEEGGGG-GRE-RED----KKKK---' 24