$re = '/http(|s):[^\'$\s]+/m';
$str = 'head: https://scooptacular.net
head: https://scooptacular.net/img/uploaded/379d05029c0d84618c70ac037a25fd88.jpg
head: https://scooptacular.net/img/uploaded/4baaa58a1a37fd3da3e4e78caf366b7f.jpg
head: https://fonts.googleapis.com/css?family=Montserrat:400,700
head: https://fonts.googleapis.com/css?family=Kaushan+Script\' rel=\'stylesheet\' type=\'text/css\'>
head: https://fonts.googleapis.com/css?family=Droid+Serif:400,700,400italic,700italic\' rel=\'stylesheet\' type=\'text/css\'>
head: https://fonts.googleapis.com/css?family=Roboto+Slab:400,100,300,700\' rel=\'stylesheet\' type=\'text/css\'>
head: https://oss.maxcdn.com/libs/html5shiv/3.7.0/html5shiv.js
head: https://oss.maxcdn.com/libs/respond.js/1.4.2/respond.min.js
meta: https://scooptacular.net
meta: https://scooptacular.net/img/uploaded/379d05029c0d84618c70ac037a25fd88.jpg
meta: https://scooptacular.net/img/uploaded/4baaa58a1a37fd3da3e4e78caf366b7f.jpg
meta: https://fonts.googleapis.com/css?family=Montserrat:400,700
meta: https://fonts.googleapis.com/css?family=Kaushan+Script\' rel=\'stylesheet\' type=\'text/css\'>
meta: https://fonts.googleapis.com/css?family=Droid+Serif:400,700,400italic,700italic\' rel=\'stylesheet\' type=\'text/css\'>
meta: https://fonts.googleapis.com/css?family=Roboto+Slab:400,100,300,700\' rel=\'stylesheet\' type=\'text/css\'>
meta: https://oss.maxcdn.com/libs/html5shiv/3.7.0/html5shiv.js
meta: https://oss.maxcdn.com/libs/respond.js/1.4.2/respond.min.js
meta: https://scooptacular.net
meta: https://scooptacular.net/img/uploaded/379d05029c0d84618c70
http://google.com.ar
';
preg_match_all($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