$re = '/^https?:\/\/[A-Za-z0-9:/.]+(?:([ ,;])https?:\/\/[A-Za-z0-9:/.]+(?:\1[A-Za-z0-9:/.]+)*)?$/m';
$str = 'e.g this should match as it only uses one type of special character (semi-colon):
https://hello.com/example1;https://hello.com.com/example2;https://hello.com.com/example3
This should fail as it mixes two types of special characters (space and semi-colon)
https://hello.com/example1; https://hello.com.com/example2 ;https://hello.com.com/example3
https://hello.com/example1
test';
preg_match_all($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