regex, problem with backreference in pattern with preg match all

[ahmedhelmy007]

i wonder what is the problem with the backreference here:

preg_match_all('/__((\'|")([^\1]+)\1/', "__('match this') . 'not this'", $matches);

it is expected to match the string between __('') but actually it returns:

match this') . 'not this

[coopster]

Looks like it is getting greedy. Try adding a non-greedy modifier to your expression. Also, you may want to escape the parenthesis. It may not be necessary but since it is meant to capture subpatterns I typically make a habit of escaping them when they are literal values.