I used the below perl script to remove out the partial cds, but its not working correctly and i am getting a blank output file. Can any body find out the the mistake and kindly correct it.

use strict;
use warnings;
open (fh, '<C:\Users\bulbul\Desktop\New folder\Unigene.transdecoder.cds.txt') or die "file not found,$!";
open (out, ">bulbul.txt");
while (my $line = "Unigene.transdecoder.cds.txt") {
    chomp $line;
    print "processing $line\n";
    my ($id, $rna_sq) = split(/\s+/, $line);

    while ($rna_sq =~ /atg/g) {

        my $start = pos($rna_sq) - 3; 

          last $rna_sq =~ /tga|taa|tag/g;

        my $stop    = pos($rna_sq);
        my $genelen = $stop - $start;

        my $gene    = substr($rna_sq, $start, $genelen);
        print "\t" . join(' ', $id, $start+1, $stop, $gene, $genelen) . "\n";
    }
}