print $fh join("\n", sort { $alt{$b} <=> $alt{$a} } keys %alt), "\n"
or die "print $tmp: $!\n";
chmod($mode, $fh) or die "fchmod $tmp: $!\n";
close $fh or die "close $tmp $!\n";
rename($tmp, $alt) or die "rename $tmp => $alt: $!\n";
print $fh join("\n", sort { $alt{$b} <=> $alt{$a} } keys %alt), "\n"
or die "print $tmp: $!\n";
chmod($mode, $fh) or die "fchmod $tmp: $!\n";
close $fh or die "close $tmp $!\n";
rename($tmp, $alt) or die "rename $tmp => $alt: $!\n";