关于fasta序列折叠

#!/usr/bin/perl -w
use strict;
print "input your file,then press Enter!\n";
my $file=;
my $key;
my %seq;
open IN,"<$file";
open OUT,">resulta";
   while (){
     if (/>/){ $key=$_;}else{$seq{$key}.=$_;}

   foreach my $target(values %seq){
         chomp$target;
    my $first=substr($seq{$key},0,60);
    my $second=substr($seq{$key},61);
   print OUT"$key\n$first\n$second\n";
   }
  }
exit;
######关于fasta序列折叠######################