How-to create a Password Generator using PHP

Good code, but those ‘for’ cycles look like they’re not in place For letters, you can use range(‘a’,'z’); and range(‘A’,'Z’);, then for ’specials’ the cycle could be placed with range(33,47);, same with numbers. They will create array’s with the needed symbols It’s more practical, and it looks cleaner, and of course the performance SHOULD be better

Or, simply:
$ pear install Text_Password
and then in your code:
require_once ‘Text/Password.php’;
echo Text_Password::create();

You don’t have to have a hosting provider’s permission to use PEAR packages (hint: they work without PEAR installer).
As for the code, how about something like this:

function randomString($length = 16)
{
$alhpabet = ''ABCDEFGHIJKLMNOPORRQSTUWVXYZabcdefghijklmnoprqstuwvxyz0123456789!@#$%^&*?';
$alphabetLenght = strlen($alphabet) - 1;
$string = '';
while($length) {
$string .= $alphabet[mt_rand(0, $alphabetLenght)];
--$length;
}
return $string;
}


For a “special symbols in 25% of the password” thing you would have to have a separate variable for those special symbols and then in the loop something like this:

if (mt_rand(0,3)) {
$string .= $alphabet[mt_rand(0, $alphabetLenght)];
} else {
$string .= $specialSymbols[mt_rand(0, strlen($specialSymbols))];
}

That won’t guarantee you perfect 25% every time, but statistically it should oscillate around that number (gotta love math!) and it’s much more elegant solution I think.

Correction of some errors I’ve made:
- it should be “strlen($specialSymbols) – 1″
- $alphabet instead of $alhpabet in the 1st line of the function
- there is a “‘” repeated with the $alphabet declaration

Thanks for sharing a code sample, but please don’t teach people to use bad coding style. Omitting braces is a recipe for disaster here:

if ($use_caps) for ($ca = 65; $ca <= 90; $ca++) $caps[] = $ca; // create A-Z

Also, the way of specifying options can get awkward. A bit mask is more elegant here:

function create_password($options) {
  if ($options & PASSWORD_USE_SPECIALS) {
    /* ... */
  }
}

And as said before, don't reinvent the wheel.

Nice script. Thanks

I have one concern with it (sorry, I’m going to be a little bit blunt), but the syntax you use is atrocious and disgusting:

if ($use_numeric) for ($nu = 48; $nu < = 57; $nu++) $numbers[] = $nu;

This is acceptable though:

if ($use_numeric) $numbers = range(48, 57);

but this is better:

if ($use_numeric)
$numbers = range(48, 57);

Code readability is very important...

Sorry for the double post. In the line of code after “but this is better:” the line: “$numbers = range(48, 57);” should have been indented in my last comment…

Hello Olaf,

You are right. if we use the single row without using braces like if ($use_numeric) $numbers = range(48, 57);
is very short. but the beginners can’t able to understood it at first look.