$re = '/(https?:\/\/imgur\.com\/a\/(.*?)(?:[#\/].*|$))/m';
$str = 'http://imgur.com/a/ksU2j/embed#0
http://imgur.com/a/ksU2j#0
http://imgur.com/a/ksU2j
http://imgur.com/a/ksU2j/all
http://imgur.com/a/ksU2j/embed?backgrou...umbs=true
how to get id & full url?';
preg_match_all($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