use Text::CSV;
use Data::Dumper qw(Dumper);

print "Enter file name: \n";
my $file = <STDIN>;
chomp $file;

print "Enter output file name: \n";
my $ofile = <STDIN>;
 
my $csv = Text::CSV->new({ sep_char => ',' });
my @fasta;

open(my $data, '<', $file) or die "Could not open '$file' $!\n";
while (my $line = <$data>) {
chomp $line;
 
  if ($csv->parse($line)) {
 
      my @fields = $csv->fields();
      #print Dumper \@fields;
      $fields[4]=~s/\s//gs; #removes spaces within the sequence
      push @fasta,"\>$fields[0]\_$fields[1]\_$fields[2]\_$fields[3]\n$fields[4]\n"; #outputs the correct format
      
 
  } else {
      warn "Line could not be parsed: $line\n";
  }
}

#print Dumper \@fasta;

open (FH,">$ofile"),

print FH"@fasta",

close;

end;