Regex to find information in PHP function - php

Question

I'm working on a regex but I'm not able to fix it.
I'm scanning documents (.php) with PHP and I'm looking for: $__this('[TEXT]') or $__this("[TEXT]")
So my question is: can somebody help me with a regex that searches in a string for: $__this('[TEXT]') or $__this("[TEXT]") and gives me [TEXT]
UPDATE (with answer, thanks to #Explosion Pills):
$string = '$__this("Foo Bar<br>HelloHello")';
preg_match('/\$__this\(([\'"])(.*?)\1\)/xi', $string, $matches);
print_r($matches);

Answer 1

preg_match('/
\$__this # just $__this. $ is meta character and must be escaped
\( # open paren also must be escaped
([\'"]) # open quote (capture for later use). \' is needed in string
(\[ # start capture. open bracket must also be escaped
.*? # Ungreedily capture whatever is between the quotes
\]) # close the open bracket and end capture
\1 # close the quote (captured earlier)
\) # close the parentheses
/xi' # ignore whitespace in pattern, allow comments, case insensitive
, $document, $matches);
The captured text will be in $matches[2]. This assumes one possible capture per line. If you need more, use preg_match_all.

Answer 2

how about:
preg_match('/\$__this(?:(\'|")\((.+?)\)\1)/', $string);
explanation:
(?-imsx:\$__this(?:(\'|")\((.+?)\)\1))
matches as follows:
NODE EXPLANATION
----------------------------------------------------------------------
(?-imsx: group, but do not capture (case-sensitive)
(with ^ and $ matching normally) (with . not
matching \n) (matching whitespace and #
normally):
----------------------------------------------------------------------
\$ '$'
----------------------------------------------------------------------
__this '__this'
----------------------------------------------------------------------
(?: group, but do not capture:
----------------------------------------------------------------------
( group and capture to \1:
----------------------------------------------------------------------
\' '''
----------------------------------------------------------------------
| OR
----------------------------------------------------------------------
" '"'
----------------------------------------------------------------------
) end of \1
----------------------------------------------------------------------
\( '('
----------------------------------------------------------------------
( group and capture to \2:
----------------------------------------------------------------------
.+? any character except \n (1 or more
times (matching the least amount
possible))
----------------------------------------------------------------------
) end of \2
----------------------------------------------------------------------
\) ')'
----------------------------------------------------------------------
\1 what was matched by capture \1
----------------------------------------------------------------------
) end of grouping
----------------------------------------------------------------------
) end of grouping
----------------------------------------------------------------------

Answer 3

Here's a solution that will catch strings with quotes and apostrophes in them as well.
$txt = "
blah blah blah
blah \$_this('abc') blah
blah \$_this('a\"b\"c') blah balah \$_this('a\"b\"c\'')
\$_this(\"123\");\$_this(\"1'23\") \$_this(\"1'23\\\"\")
";
$matches = array();
preg_match_all('/(?:\$_this\()(?:[\'"])(.*?[^\\\])(?:[\'"])(?:\))/im', $txt, $matches);
print_r($matches[1]);