# slurp in file into a string
$/=''; $DNA = <FILE>; 
# remove \n at end
chomp($DNA);

##</code><code>##

# replace line endings with commata
$DNA =~ s/\n/,/;

##</code><code>##

# replace newlines with commas
$DNA =~ s/\n/,/g;

##</code><code>##

# replace newlines with commas
$DNA =~ tr/\n/,/;