$re = '/^(?P<Root>file\:\/\/\/(?:[A-Za-z]+):(?:\/|\\\\)|https\:\/\/)(?P<Relative>(?:(?:[^<>:"\/\\\\|?*\n])+(?:\/|\\\\))+)(?P<File>(?:[^<>:"\/\\\\|?*\n]+)(?:\.(?:pdf)))$/m';
$str = 'file:///D:/Documents/My%20Documents/T09_27jun-17jul_V_Fro.pdf
file:///z:/Documents/My%20Documents/pdfs/eggs,%20milk,%20fruit.pdf
file:///zz:/Documents/My%20Documents/example.folder/icebreaker.pdf
file:///abv:/program%20shmogram%20(x86)/CoolTheVideoGameTheMovie/lewd.mods/uwuDialogueforFemales.pdf
file:///h:/Documents/My%20Documents/example.folder/New%20folder/ExamplE%20folder%203/very_cool_kanye.pdf
https://www.samsclub.com/savings/20230626/T09_27jun-17jul_V_Fro.pdf
https://whatkindofprefixisthis.RobertTheWebsite.io/AboutUs/Who-Da-frick_IS_Robert-anyways.pdf';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php