use strict;
use warnings;
use Bio::SeqIO;

my $in = Bio::SeqIO->new( -fh => \*ARGV, -format => 'Fasta' );

while ( my $seq = $in->next_seq() ) {
	my $protein;
	$protein .= codon2aa($_) for $seq->seq =~ /.../g;
	print '>' . $seq->id . "\n$protein\n";
}

#' codon2aa
#'
#' A subroutine to translate a DNA 3-character codon to an amino acid

sub codon2aa {
	my ($codon) = @_;

	if    ( $codon =~ /GC./i )        { return 'A' }    # Alanine
	elsif ( $codon =~ /TG[TC]/i )     { return 'C' }    # Cysteine
	elsif ( $codon =~ /GA[TC]/i )     { return 'D' }    # Aspartic Acid
	elsif ( $codon =~ /GA[AG]/i )     { return 'E' }    # Glutamic Acid
	elsif ( $codon =~ /TT[TC]/i )     { return 'F' }    # Phenylalanine
	elsif ( $codon =~ /GG./i )        { return 'G' }    # Glycine
	elsif ( $codon =~ /CA[TC]/i )     { return 'H' }    # Histidine
	elsif ( $codon =~ /AT[TCA]/i )    { return 'I' }    # Isoleucine
	elsif ( $codon =~ /AA[AG]/i )     { return 'K' }    # Lysine
	elsif ( $codon =~ /TT[AG]|CT./i ) { return 'L' }    # Leucine
	elsif ( $codon =~ /ATG/i )        { return 'M' }    # Methionine
	elsif ( $codon =~ /AA[TC]/i )     { return 'N' }    # Asparagine
	elsif ( $codon =~ /CC./i )        { return 'P' }    # Proline
	elsif ( $codon =~ /CA[AG]/i )     { return 'Q' }    # Glutamine
	elsif ( $codon =~ /CG.|AG[AG]/i ) { return 'R' }    # Arginine
	elsif ( $codon =~ /TC.|AG[TC]/i ) { return 'S' }    # Serine
	elsif ( $codon =~ /AC./i )        { return 'T' }    # Threonine
	elsif ( $codon =~ /GT./i )        { return 'V' }    # Valine
	elsif ( $codon =~ /TGG/i )        { return 'W' }    # Tryptophan
	elsif ( $codon =~ /TA[TC]/i )     { return 'Y' }    # Tyrosine
	elsif ( $codon =~ /TA[AG]|TGA/i ) { return '_' }    # Stop
	else {
		return '*';
	}
}