preg_split/preg_match_all: string -> paragraph

[CrashRoX]

I want to use preg_match_all to find the location of a string in a series of paragraphs, case does NOT matter. What I want to happen is after it finds the string it captures the entire paragraph. Each paragraph is returned as a separate result. I tried doing something similar with preg_split, but I ended up with extra paragraphs and data. Any suggestions are appreciated. Thanks.

$string = "this contains some text and a special keyword that is 'SPECIAL KEY!'. More text, more text, more text!! Yay!

this is a second paragraph that contains the same special key! but in lower case. I also want this entire paragraph as a result.

this paragraph doesnt have any key that is special, so it should be discarded.
";

preg_match_all('/special key!/', $string, $res);

print_r($res);

[zabmilenko]

Try this:

// bad form to use $string
$text = "this contains some text and a special keyword that is 'SPECIAL KEY!'. More text, more text, more text!! Yay!

this is a second paragraph that contains the same special key! but in lower case. I also want this entire paragraph as a result.

this paragraph doesnt have any key that is special, so it should be discarded.
"; 

$matches = array();
preg_match_all('/^.*?special key.*?$/imU', $text, $matches);


print '<pre>' . print_r($matches, true) . '</pre>';

My results:

    [0] => Array
        (
            [0] => this contains some text and a special keyword that is 'SPECIAL KEY!'. More text, more text, more text!! Yay!
            [1] => this is a second paragraph that contains the same special key! but in lower case. I also want this entire paragraph as a result.
        )

[CrashRoX]

Works perfect!

Thank you!