#!/bin/perl
##################################################
# This program prints all codons in the first
# reading frame.
#
# This problem requires familiarity with basic I/O,
# scalar operators, and iteration.
##################################################

# Initalization
$sequence = "GTAACCGAACCTAGGAGTTAAA";
print "DNA sequence: $sequence\n";

$seqLen = length ($sequence);  # Get sequence length

$currPos = 0;           # initalize current position

while ($currPos < $seqLen - 2) { 
   print "Codon #", $currPos/3+1, " is: ", substr($sequence,$currPos,3) , "\n";
   $currPos = $currPos + 3;
}

exit;