if (mbsubstr($element->href, 0, 2) == "//") {
$element->href = $urlparts['scheme'].":".$element->href;
}
if (mbsubstr($element->href, 0, 1) == "/") {
$element->href = $base_url.$element->href;
}
if (mbsubstr($element->href, 0, 2) == "./") {
$element->href = substr($element->href, 2);
}
if (mbsubstr($element->href, 0, 5) != "http:"
&& mbsubstr($element->href, 0, 6) != "https:"
) {
$element->href = $base_url.$url_path.$element->href;
}
which looks for the href tag and will send the spider there to crawl it
then it puts it into the database by some INSERT SQL commands: (https://git.sturtz.cf/Sturtz_Network/sturtz-search-public/sr...)