#!/usr/bin/perl 
#sample simple fasta parser

use strict;
use warnings;

my $file = shift;
open (INFASTA, '<' , $file) or die $!;
my $id;
my $seq = '';
while (my $line = <INFASTA>){
        chomp $line;

        if ($line =~ />(\S+)\s?(.*)/){
                print "$seq\n" if $seq ne '';
                $seq = '';
                $id = $1;
                print ">$id" , "\n";
        }else {
                $seq .= $line;
        }
}
print "$seq\n";