$re = '/\bif\s*([^:]+):\s+([^:]+)\s+(?::else:\s+([^:]+)\s+)?endif\b/m';
$str = 'Text if(stat(fire) ): x :else: w endif
if o: s endif;
if is_night(): die(); horribly(); :else: live() endif
attack(5); if attack_was_lethal(): heal(1); gain(block, get_stat(strength)); :else: heal(-1) endif; draw(1)
if multiline():
abc
:else:
def
endif';
preg_match_all($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