random string number generator in php codeigniter
// RANDOM NUMBER GENERATOR
function random($length_of_string) {
// String of all alphanumeric character
$str_result = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz';
// Shufle the $str_result and returns substring
// of specified length
return substr(str_shuffle($str_result), 0, $length_of_string);
}