indent C headers for readability

indentr.pl

$reserved = 0;
$indent = 0;

while (<>) {
    if ($reserved) {
	$indent++;
	$reserved = 0;
    }

    if (/^#if/) {
	$reserved = 1;
    }

    if (/^#else/) {
	$indent--;
	$reserved = 1;
    }

    if (/^#endif/) {
	$indent--;
    }

    $space = "";
    for ($i = 0; $i < $indent; $i++) {$space .= "__";}
    print ($space . $_);
}