Return random characters

[slpctrl]

How would I return any 5 random characters from a string? Let's say I've got this:

 

 

<?php
$str1 = md5(microtime() * mktime());
$str2 = str_shuffle($str1);
$str = substr($str2,0,5);
?>

 

line 1 gets a string of random characters

line 2 shuffles those random characters

line 3 gets the first 5 characters

 

 

Instead of getting the first 5 characters, how can I return 5 random characters?

[fanfavorite]

Something like this?

 

$chars = "abcdefghijkmnopqrstuvwxyz023456789";    
srand((double)microtime()*1000000);    
$i = 0;    
$pass = '' ;    
while ($i <= 4) {        
$num = rand() % 33;        
$tmp = substr($chars, $num, 1);        
$pass = $pass . $tmp;        
$i++;    
}  

[BlueSkyIS]

you are already returning 5 random characters. str_shuffle makes the string random, then you take the first 5 characters. it literally can't get 'more random' than that. if it makes you feel better, you could use str_shuffle again, then take the first 5 characters. but since str_shuffle already randomized the first 5 chars, it's a waste of effort. grad level stats, don't you know. 

[Ken2k7]

You can use uniqid(), but the way you have it, it's already unique even before the str_shuffle.

[slpctrl]

you are already returning 5 random characters. str_shuffle makes the string random, then you take the first 5 characters. it literally can't get 'more random' than that. if it makes you feel better, you could use str_shuffle again, then take the first 5 characters. but since str_shuffle already randomized the first 5 chars, it's a waste of effort. grad level stats, don't you know. 

 

Yeah that's what I was thinking. Thanks I'm dumb