use strict;
use warnings;
require 5.8.0;

my $num = 12;

print format_str( "%.01f", $num ), "\n";

sub format_str {
	my $string;
	open STROUT, ">", \$string or die "You fool: $!\n";
	printf STROUT shift, @_;
	close STROUT or die "trying: $!\n";
	return $string;
}