[PHP-WIN] how to avoid repetition?

I need to generate 10million 12-char string and I am able to do so, however the problem is how to avoid repetition keeping each string unique? it will be a disaster to compare each string,isn't it? ps Thanks Yong. Bo -- PHP Windows Mailing List (http://www.php.net/) To unsubscribe,

[PHP-WIN] what's wrong with this while loop?

Following my code is to write a 15digit random generated password into a file named test.txt. I was trying to keep it random generating 100 passwords and be written into test.txt by using a while loop, however, the result is strange. Take a look at the code (most of it is from php.net) and what