Regex to match specific string not enclosed by another, different specific string

Question

I need a regex to match a string not enclosed by another different, specific string. For instance, in the following situation it would split the content into two groups: 1) The content before the second {Switch} and 2) The content after the second {Switch}. It wouldn't match the first {Switch} because it is enclosed by {my_string}'s. The string will always look like shown below (i.e. {my_string}any content here{/my_string})

Some more  
  {my_string}
  Random content
  {Switch} //This {Switch} may or may not be here, but should be ignored if it is present
  More random content
  {/my_string}
Content here too
{Switch}
More content

So far I've gotten what is below which I know isn't very close at all:

(.*?)\{Switch\}(.*?)

I'm just not sure how to use the [^] (not operator) with a specific string versus different characters.

Answer 1

Try this simple function:

function find_content()

function find_content($doc) {
  $temp = $doc;
  preg_match_all('~{my_string}.*?{/my_string}~is', $temp, $x);
  $i = 0;
  while (isset($x[0][$i])) {
    $temp = str_replace($x[0][$i], "{REPL:$i}", $temp);
    $i++;
    }
  $res = explode('{Switch}', $temp);
  foreach ($res as &$part) 
    foreach($x[0] as $id=>$content)
      $part = str_replace("{REPL:$id}", $content, $part);
  return $res;
  }

Use it this way

$content_parts = find_content($doc); // $doc is your input document
print_r($content_parts);

Output (your example)

Array
(
    [0] => Some more
{my_string}
Random content
{Switch} //This {Switch} may or may not be here, but should be ignored if it is present
More random content
{/my_string}
Content here too

    [1] => 
More content
)