Complete and test two simple PHP functions

We need 2 PHP functions completed and tested. (there is a third utility function included that should work as is but you will need to test that one) Function 1: function one_random_line(){ $folder_path = '/abc/xyz/'; //step 1 - get one random file from folder_path //step 2 - get one random line from step 1 file //step 3 - return line from step 3' } Function 2: function random_anchorfy($html,$url){ //step 1 - pick random sub-string of len 1 to 3 words $words = explode(' ', $html); $numWords = count($words); $step_1_str = join(' ', array_slice($words, mt_rand(0, $numWords - 3), mt_rand(1, 3))); //step 3 - test $step_1_str has no special characters e.g. isValid($step_1_str) //step 4 - if step 3 is false then repeat step 2 //step 5 - str_replace($step_2_str,"<a href='{$url}'>{$step_2_str}</a>",$html); //step 6 - return $html as modified in step 5 } Utility Function; function isValid($str) { return !preg_match('/[^A-Za-z0-9.#\\-$]/', $str); }