Generate random 5 characters string
You can try it simply like this:
$length = 5;
$randomletter = substr(str_shuffle("abcdefghijklmnopqrstuvwxyz"), 0, $length);
more details: http://forum.arnlweb.com/viewtopic.php?f=7&t=25
If for
loops are on short supply, here's what I like to use:
$s = substr(str_shuffle(str_repeat("0123456789abcdefghijklmnopqrstuvwxyz", 5)), 0, 5);
A speedy way is to use the most volatile characters of the uniqid function.
For example:
$rand = substr(uniqid('', true), -5);
$rand = substr(md5(microtime()),rand(0,26),5);
Would be my best guess--Unless you're looking for special characters, too:
$seed = str_split('abcdefghijklmnopqrstuvwxyz'
.'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
.'0123456789!@#$%^&*()'); // and any other characters
shuffle($seed); // probably optional since array_is randomized; this may be redundant
$rand = '';
foreach (array_rand($seed, 5) as $k) $rand .= $seed[$k];
Example
And, for one based on the clock (fewer collisions since it's incremental):
function incrementalHash($len = 5){
$charset = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
$base = strlen($charset);
$result = '';
$now = explode(' ', microtime())[1];
while ($now >= $base){
$i = $now % $base;
$result = $charset[$i] . $result;
$now /= $base;
}
return substr($result, -5);
}
Note: incremental means easier to guess; If you're using this as a salt or a verification token, don't. A salt (now) of "WCWyb" means 5 seconds from now it's "WCWyg")