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sketchMedia · 06-11-2008, 10:09 AM

Nice script, thanks for sharing.

One thing however, there is a mistake, the script generates a 'undefined offset' because you have set the max value of mt_rand to '62' (number of elements in the array) so every now and again you will get the '62' being produced and used as a key for the array, however the maximum array key value is only '61' (php is zero indexed so the first value is 0 not 1) thus the key '62' doesn't exist.
to rectify just subtract 1 from the max value of mt_rand

PHP Code:


			
<?php
function myRandomStr($passLen=16, $shakes=5)
{
    // Get some letters and integers easy and quick into arrays
    $smal_letters = range('a','z');
    $big_letters = range('A','Z');
    $integers = range('0', '9');

    // merge thoose arrays above to one array
    $combined = array_merge($smal_letters, $big_letters, $integers);
    
    // shake it around abit
    for($s = 0; $s < intval($shakes); ++$s)
    {
        shuffle($combined);
    }
    
    // find out how big the array is
    $len = count($combined) - 1;
    // then finaly create the string
    for($i = 0; $i < intval($passLen); ++$i)
    {
        // Choose some random letters from the array
        $salt = mt_rand(0, $len);
        echo $combined[$salt];
    }
}

// Lets try a 15 char long and with 5 shakes.
myRandomStr(15, 5);

that should now run correctly.

apart from that its nice, thanks m8.

06-11-2008, 10:09 AM	#4 (permalink)
sketchMedia The Frequenter Join Date: Oct 2007 Location: Manchester, UK Posts: 469 Thanks: 26	Nice script, thanks for sharing. One thing however, there is a mistake, the script generates a 'undefined offset' because you have set the max value of mt_rand to '62' (number of elements in the array) so every now and again you will get the '62' being produced and used as a key for the array, however the maximum array key value is only '61' (php is zero indexed so the first value is 0 not 1) thus the key '62' doesn't exist. to rectify just subtract 1 from the max value of mt_rand PHP Code: <?php function myRandomStr($passLen=16, $shakes=5) { // Get some letters and integers easy and quick into arrays $smal_letters = range('a','z'); $big_letters = range('A','Z'); $integers = range('0', '9'); // merge thoose arrays above to one array $combined = array_merge($smal_letters, $big_letters, $integers); // shake it around abit for($s = 0; $s < intval($shakes); ++$s) { shuffle($combined); } // find out how big the array is $len = count($combined) - 1; // then finaly create the string for($i = 0; $i < intval($passLen); ++$i) { // Choose some random letters from the array $salt = mt_rand(0, $len); echo $combined[$salt]; } } // Lets try a 15 char long and with 5 shakes. myRandomStr(15, 5); that should now run correctly. apart from that its nice, thanks m8. __________________ Last edited by sketchMedia : 06-11-2008 at 12:10 PM. Reason: removed mistake in last loop, see salathe's post below