use strict;
use warnings;
use Digest::SHA;

my $file = shift;

print calculateSHA($file);
print "\n";

sub calculateSHA{
	my $data = shift;
	my $val = 0;
	eval{
		my $sha1 = Digest::SHA->new(256);
		#supposed to be portable and os independant? not working. 
		$sha1->addfile($data, "p");
		$val = $sha1->hexdigest;
	};
	if($@){
		print "An error occurred calculating the SHA-Value. Cannot verify integrity of file\n$@\n";
	}
	return $val;
}