php random x digit number

I usually just use RAND() http://php.net/manual/en/function.rand.php

e.g.

rand ( 10000 , 99999 );

for your 5 digit random number

You can use rand() together with pow() to make this happen:

$digits = 3;
echo rand(pow(10, $digits-1), pow(10, $digits)-1);

This will output a number between 100 and 999. This because 10^2 = 100 and 10^3 = 1000 and then you need to subtract it with one to get it in the desired range.

If 005 also is a valid example you'd use the following code to pad it with leading zeros:

$digits = 3;
echo str_pad(rand(0, pow(10, $digits)-1), $digits, '0', STR_PAD_LEFT);