$re = '/^\s*(((\/\/|#)[^\n]*\n*)|(\/\*((?!\*\/)(.|\n))+\*\/)|\s)*\s*(\$|echo|class\s+\w|\/\/php|#php|mysql_|namespace|use|include|require|function\s+[^\(\s]+\s*\(\s*\$|((if|while|for|switch|foreach)\s*\(\s*\$\w))/i';
$str = '// nějaké podmínky
if($sel->ulcp != $ulcp){$co .= ", ulcp = \'$ulcp\'";}
if($sel->ulcp2 != $ulcp2){$co .= ", ulcp2 = \'$ulcp2\'";}
if($sel->ulcp3 != $ulcp3){$co .= ", ulcp3 = \'$ulcp3\'";}';
preg_match($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