When you open a file the way he is, do you need to use a redirect?

unless (open (BLAST, "<result.fasta")){
    print "Can not open data file \n";
    exit;
}
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I prefer opening files this way:

open BLAST, "<result.fasta" or die "Can not open data file: $!\n";
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You may try adding a print statement in the foreach loop to print $record to make sure it has the data you want in it.