BOL

I am using this perl code right nowadays.

#!/usr/bin/perl
use warnings;
use strict;
open(FASTA, "<", seq.fa) or die("Can't open\n");
my %singleLineSequences;
my $sequence_id;
while(){
    my $line = $_; chomp($line);
    if ($line =~ m/^>(\S+)/){
        $sequence_id = $1;  
        $singleLineSequences{$sequence_id} = ""; 
        }
    else {
        $singleLineSequences{$sequence_id} = $singleLineSequences{$sequence_id} . $line;
        }
   }


foreach my $sequence_entry (keys %singleLineSequences){
    my $currentSequence = $singleLineSequences{$sequence_entry};
    my $lengthSequence = length($currentSequence);
    print $sequence_entry . "," . $lengthSequence . "\n";
}