$re = '/- - .* "GET .*\?do\=.*/';
$str = '- - [27/Sep/2013:12:41:21 +0200] "GET /shop/index.php?do=/blog/add HTTP/1.1" 301 566 "http://www.tld.com/shop/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; SV1;)"';
preg_match($re, $str, $matches, PREG_OFFSET_CAPTURE, 0);
// Print the entire match result
var_dump($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