To count the number of occurrences of GATC in your string (this is a FAQ): 
perldoc -q count

[download]
use warnings;
use strict;

my $substring = 'GATC';
my $count     = 0;
my $sequence  = 'GAGAGACCCCGATCGAGAGACCCGATCFGAGAVCTGATCCCC';
while ($sequence =~ /$substring/g) { $count++ }
print "count = $count\n";

__END__

count = 3

[download]
See also: How do I compose an effective node title?

In reply to Re: stupid/simple mistake by toolic
in thread stupid/simple mistake by gogoglou

Title:
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