$re = '/^(?:https?://(?:\w+\.)+\w+(?:/\S*)*|sc-domain:(?:\w+\.)+\w+)$/m';
$str = 'For example, the below entries should pass
https://www.foo.com/
https://www.foo.com/bar/
sc-domain:www.foo.com
sc-domain:abc.com
sc-domain:www.abc.com
https://www.abc.com/
https://abc.com/
However the below entries should fail
htps://www.foo.com/
https:/www.foo.com/bar/
sc-domain:www.foo.com/
sc-domain:www.foo.com/bar
scdomain:www.foo.com
sc-domain:abc.com/
sc-domain:abc.com/abc';
preg_match_all($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