#!/usr/bin/env perl
use warnings;
use 5.014;
use lib "/home/kaiyin/bin";
use wrappers;

my $dna = "ATCGTTGAATGCAAATGACATGAC";
while ($dna =~ /\G(\w\w\w)*?TGA/g) {  # note the minimal *?
   print "Got a TGA stop codon at position ", pos $dna, "\n";
}