/**
* Generates a random string of a given type and length.
*
*
* $str = Text::random(); // 8 character random string
*
* The following types are supported:
*
* alnum
* : Upper and lower case a-z, 0-9 (default)
*
* alpha
* : Upper and lower case a-z
*
* hexdec
* : Hexadecimal characters a-f, 0-9
*
* distinct
* : Uppercase characters and numbers that cannot be confused
*
* You can also create a custom type by providing the "pool" of characters
* as the type.
*
* @param string $type a type of pool, or a string of characters to use as the pool
* @param integer $length length of string to return
* @return string
* @uses UTF8::split
*/
public static function random($type = NULL, $length = 8)
{
if ($type === NULL) {
// Default is to generate an alphanumeric string
$type = 'alnum';
}
$utf8 = FALSE;
switch ($type) {
case 'alnum':
$pool = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
break;
case 'alpha':
$pool = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
break;
case 'hexdec':
$pool = '0123456789abcdef';
break;
case 'numeric':
$pool = '0123456789';
break;
case 'nozero':
$pool = '123456789';
break;
case 'distinct':
$pool = '2345679ACDEFHJKLMNPRSTUVWXYZ';
break;
default:
$pool = (string) $type;
$utf8 = !UTF8::is_ascii($pool);
break;
}
// Split the pool into an array of characters
$pool = $utf8 === TRUE ? UTF8::str_split($pool, 1) : str_split($pool, 1);
// Largest pool key
$max = count($pool) - 1;
$str = '';
for ($i = 0; $i < $length; $i++) {
// Select a random character from the pool and add it to the string
$str .= $pool[mt_rand(0, $max)];
}
// Make sure alnum strings contain at least one letter and one digit
if ($type === 'alnum' and $length > 1) {
if (ctype_alpha($str)) {
// Add a random digit
$str[mt_rand(0, $length - 1)] = chr(mt_rand(48, 57));
} elseif (ctype_digit($str)) {
// Add a random letter
$str[mt_rand(0, $length - 1)] = chr(mt_rand(65, 90));
}
}
return $str;
}
