$re = '/\[DE\](.*?)\[\/DE\]/s';
$str = '[DE]lkjhkjh
huhu[/DE]
[EN]
lkjlkjlkjlkjhkhj
sjdkjdhfksjfhsdkshkjhf
sfksjdksjfkdsfksjdfh
skjfkjskfjdsfh
dsjfhskjfdkjsfhd
[/EN]
[DE]
lsdkflkdsj
kjlskdjfldj
kjlskdjlksfdljs
flkslfkslfsdkfldsfdskfljdsk
lksjdlkslfdkslfsdfkjfs
jkjhkjkjhkjh
lkjlkljjlkjklj
[/DE]
';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php