Dear monks, I wondered if someone could tell me why my very simple program is taking so long to exit after it has printed the results to the screen? Many thanks.

#! /usr/bin/perl -w

use strict;

my $num_of_params;
my $dna1;
my $base1;

$num_of_params = @ARGV;

if ($num_of_params < 2)
{
    die ("\n you havent entered enough parameters! \n");
}

open (INFILE, $ARGV[0]) or die "unable to open file";

my @lines = <INFILE>;
chomp @lines;

$dna1 = join ('', @lines);
$dna1 =~ s/\s//g;
$dna1 =~ s/^>genome//;
@lines = split ('', $dna1);



my $count_of_A = 0;
my $count_of_C = 0;
my $count_of_G = 0;
my $count_of_T = 0;
my $errors = 0;

foreach $base1 (@lines)  {

   if (($base1 eq 'A') || ($base1 eq 'a'))  {
       ++$count_of_A;
   }

   elsif (($base1 eq 'G') || ($base1 eq 'g')) {
      ++$count_of_G;
   }

   elsif (($base1 eq 'C') || ($base1 eq 'c')) {
     ++$count_of_C;
   }

   elsif (($base1 eq 'T') || ($base1 eq 't')) {
     ++$count_of_T;
   }

   else  {
      print "There are errors in this DNA sequence.  Please check that
+ your sequence contains only A C T and G\n";
       ++$errors;
   }
}

print "\nThere are $count_of_A A's in this sequence\n\n";
print "There are $count_of_G G's in this sequence\n\n";
print "There are $count_of_T T's in this sequence\n\n";
print "There are $count_of_C C's in this sequence\n\n";
print "There are $errors errors in this sequence\n\n";

exit;
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