The translate operator with the same search and replace list will return a count of the number of matched characters. Read all about it in the perlop manpage. 


while ($line = <INPUT>) {
   if ($line =~ tr/ACGT/ACGT/ > 250) { print $line; }
}

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In reply to Re: simple but stuck by YuckFoo
in thread Base sequence length in fasta format file by lolly

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