#!/usr/bin/perl
#
# Print a file backwards
#

open( FILE, "test.txt" )
  or die( "Can't open file file_to_reverse: $!" );

@lines = reverse <FILE>;
foreach $line (@lines) {
  $line = reverse $line;
  print $line;
}

##</code><code>##

#!/usr/bin/perl
#
# Convert DNA to bits and see what comes out
#
use strict;
use warnings;

open my $fh, "<:encoding(UTF-8)", "Homo_sapiens.GRCh38.dna.chromosome.2.fa" or die "$!\n";
# open my $fh, "<:encoding(UTF-8)", "test.txt" or die "$!\n";

my $bit = "0";
my $byte = "";
my $i = 0;

while (read($fh, my $char, 1)) {
   # ignore all other characters, escpecially those annoying NNNNNNNN, what are they anyway? 
	if ($char =~ m/[ACGT]/ ) {
		# convert bases to bits, 6 possible way to do this
		if ($char eq "A") {
			$bit = "0";		
		}
		if ($char eq "C") {
			$bit = "1";		
		}
		if ($char eq "G") {
			$bit = "0";		
		}
		if ($char eq "T") {
			$bit = "1";		
		} 		
		
		# add one bit at a time up to a byte
		if ($i < 7) {
			$i++;
			$byte .= $bit;			
		} else {
			$i = 0;
			
			# convert the byte to a string
			my $chars = length($byte);
			my @packArray = pack("B$chars",$byte);
			my $print = "@packArray";

			# only print alphanumeric characters
			if ($print =~/[a-z]|[A-Z]/) {
				print "$print";
			}			
			
			$byte = "";				
		}		
		
	}

}

print "\n";