perl -ne "print unless /^#/" infile > outfile

##</code><code>##

use strict;
use warnings;

die("usage: $0 {infile} {outfile}\n";
   if @ARGV != 2;

my ($file_in, $file_out) = @ARGV;

open(my $fh_in, '<', $file_in)
   or die("Unable to open input file \"$file_in\": $!\n");

open(my $fh_out, '>', $file_out)
   or die("Unable to create output file \"$file_out\": $!\n");

while (<$fh_in>) {
   if (!/^#/) {
      print $fh_out $_;
   }
}

##</code><code>##

use strict;
use warnings;

die("usage: $0 {filein} {fileout}\n";
   if @ARGV != 2;

my ($file_in, $file_out) = @ARGV;

open(my $fh_in, '<', $file_in)
   or die("Unable to open input file \"$file_in\": $!\n");

open(my $fh_out, '>', $file_out)
   or die("Unable to create output file \"$file_out\": $!\n");

print $fh_out (grep !/^#/, <$fh_in>);