#!/usr/bin/perl

#
# Returns the first sequence from a FASTA file
#

use warnings;

if ($ARGV[0]) { open(IN, "<$ARGV[0]") or die($!); }
else { *IN = *STDIN; }

while (<IN>) {
	if (/^>/) {
		print $_;
		while (<IN>) {
			if (/^>/) { exit(); }
			print $_;
			}
		}
	}