exclude all except from preg_match

Question

If I have a string like

$string = 'the grey fox [[function name]] jumped over the moon';

How do I remove everything from the string except what is found in the square brackets? I can find and replace the code inside the square brackets like so:

$page_function = preg_replace('#\[\[(.*?)\]\]#', '', $string);

I need a way to inverse the preg_replace so I can replace all EXCEPT the code found in the preg_replace.

Thanks!

Answer 1

What you are most likely looking for is the complement function preg_match http://php.net/manual/en/function.preg-match.php

Example from interactive shell:

php > $string = 'the grey fox [[function name]] jumped over the moon';
php > preg_match('#\[\[(.*?)\]\]#', $string, $m);
php > var_dump($m);
array(2) {
  [0]=>
  string(17) "[[function name]]"
  [1]=>
  string(13) "function name"
}