str_shuffle

Aoccdrnig to rseearch at an Elingsh uinervtisy, it deosn't mttaer in waht oredr the ltteers in a wrod are, the olny iprmoatnt tihng is that the frist and lsat ltteer is at the rghit pclae. The rset can be a toatl mses and you can sitll raed it wouthit a porbelm. Tihs is bcuseae we do not raed ervey lteter by it slef but the wrod as a wlohe.Hree's a cdoe taht slerbmcas txet in tihs way:<?php    function scramble_word($word) {        if (strlen($word) < 2)            return $word;        else            return $word{0} . str_shuffle(substr($word, 1, -1)) . $word{strlen($word) - 1};    }    echo preg_replace('/(\w+)/e', 'scramble_word("\1")', 'A quick brown fox jumped over the lazy dog.');?>It may be ufseul if you wnat to cetare an aessblicce CTCPAHA.

This page is missing a very important notice:CautionThis function does not generate cryptographically secure values, and should not be used for cryptographic purposes. If you need a cryptographically secure value, consider using random_int(), random_bytes(), or openssl_random_pseudo_bytes() instead.

This function is affected by srand():<?phpsrand(12345);echo str_shuffle('Randomize me') . '<br/>'; // "demmiezr aon"echo str_shuffle('Randomize me') . '<br/>'; // "izadmeo rmen"srand(12345);echo str_shuffle('Randomize me') . '<br/>'; // "demmiezr aon" again?>

<?php    function str_rand(int $length = 20) : string {        $ascii_codes = range(48, 57) + range(97, 122);        $codes_lenght = (count($ascii_codes)-1);        shuffle($ascii_codes);        $string = '';        for($i = 1; $i <= $length; $i++){            $previous_char = $char ?? '';            $char = chr($ascii_codes[random_int(0, $codes_lenght)]);            while($char == $previous_char){                $char = chr($ascii_codes[random_int(0, $codes_lenght)]);            }            $string .= $char;        }        return str_shuffle($string);    }?>

A proper unicode string shuffle;<?phpfunction str_shuffle_unicode($str) {    $tmp = preg_split("//u", $str, -1, PREG_SPLIT_NO_EMPTY);    shuffle($tmp);    return join("", $tmp);}?>$str = "Şeker yârim"; // My sweet loveecho str_shuffle($str); // i�eymrŢekr �echo str_shuffle_unicode($str); // Şr mreyeikâ

As noted in this documentation str_shuffle is NOT cryptographically secure, however I have seen many code examples online of people using nothing more than this to generate say random passwords.  So I though I'd share my function which while it makes use of str_shuffle also rely's on random_int() for added security. I use this function to generate salts to use when working with hashes but it can also be used to generate default passwords for new users for example.It starts with a universe of possible characters, in this case all letters (upper and lower case), 0-9, and several special characters.It then will run str_shuffle on the universe of characters a random number of times, using random_int() (currently set to 1-10)Then once the universe of possible characters has been shuffled it using random_int() once more to select the character as a random position within the shuffled string, as does that once for each character you want in the output. function secret_gen( $len=64 ) {    $secret = "";    $charset = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789!@#$%^&*()_-+=`~,<>.[]: |';    for ( $x = 1l $x <= random_int( 1, 10 ), $x++ ){        $charset = str_shuffle( $charset );    }    for ( $s = 1; $s <= $len; $s++ ) {        $secret .= substr( $charset, random_int( 0, 86 ), 1 );    }    return $secret;}

Unshuffle, using:<?php$string = "Hello World!";$seed = 1234567890;mt_srand($seed);echo $sh = str_shuffle($string);  //print 'eloWHl rodl!'echo str_unshuffle($sh, $seed); //print 'Hello World!'?><?phpfunction str_unshuffle($str, $seed){    $unique = implode(array_map('chr',range(0,254)));    $none   = chr(255);    $slen   = strlen($str);    $c      = intval(ceil($slen/255));    $r      = '';    for($i=0; $i<$c; $i++){        $aaa = str_repeat($none, $i*255);        $bbb = (($i+1)<$c) ? $unique : substr($unique, 0, $slen%255);        $ccc = (($i+1)<$c) ? str_repeat($none, strlen($str)-($i+1)*255) : "";        $tmp = $aaa.$bbb.$ccc;        mt_srand($seed);        $sh  = str_shuffle($tmp);        for($j=0; $j<strlen($bbb); $j++){            $r .= $str{strpos($sh, $unique{$j})};        }    }    return $r;}

str_shuffle isn't recommendable for passwords. Each character exists only one time).A function like the following one is better for this.<?php    function generatePassword($length = 8) {        $possibleChars = "abcdefghijklmnopqrstuvwxyz";        $password = '';        for($i = 0; $i < $length; $i++) {            $rand = rand(0, strlen($possibleChars) - 1);            $password .= substr($possibleChars, $rand, 1);        }        return $password;    }?>

To cobine functionality and simplicity of the two functions below we can have:<?phpfunction generatePasswd($numAlpha=6,$numNonAlpha=2){   $listAlpha = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';   $listNonAlpha = ',;:!?.$/*-+&@_+;./*&?$-!,';   return str_shuffle(      substr(str_shuffle($listAlpha),0,$numAlpha) .      substr(str_shuffle($listNonAlpha),0,$numNonAlpha)    );}?>

Shuffle for all encoding formats<?phpfunction unicode_shuffle($string, $chars, $format = 'UTF-8'){    for($i=0; $i<$chars; $i++)        $rands[$i] = rand(0, mb_strlen($string, $format));                    $s = NULL;                foreach($rands as $r)        $s.= mb_substr($string, $r, 1, $format);                return $s;}?>

<?php//get random string with your desire length    function getRandom($length){                $str = 'abcdefghijklmnopqrstuvwzyz';        $str1= 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';        $str2= '0123456789';        $shuffled = str_shuffle($str);        $shuffled1 = str_shuffle($str1);        $shuffled2 = str_shuffle($str2);        $total = $shuffled.$shuffled1.$shuffled2;        $shuffled3 = str_shuffle($total);        $result= substr($shuffled3, 0, $length);        return $result;    }    echo getRandom(8);//output -->//GATv3JPX//g7AzhDtR//DTboKtiL//CuWZR4cs//tmTXbzBC?>

/** * Test shuffleString */function testShuffleString() {    $shuffled = shuffleString("ĄęźćÓ");    if (\mb_strlen($shuffled) != 5) {        throw new \UnexpectedValueException("Invalid count of characters");    }    if ($shuffled == "ĄęźćÓ") {        throw new \UnexpectedValueException("The same string");    }    foreach (["Ą", "ę", "ź", "ć", "Ó"] as $char) {        if (\mb_strpos($shuffled, $char) === false) {            throw new \UnexpectedValueException("Character not found");        }    }}/** * Shuffle string * * @param $stringValue String to shuffle * @param string $startWith Shuffle $stringValue and append to $startWith * @return string Shuffled string * @author Krzysztof Piasecki<krzysiekpiasecki@gmail.com> */function shuffleString($stringValue, $startWith = "") {    $range = \range(0, \mb_strlen($stringValue));    shuffle($range);    foreach($range as $index) {        $startWith .= \mb_substr($stringValue, $index, 1);    }    return $startWith;};testShuffleString();echo shuffleString("Hello"); // > 'elHol' (something like this)echo shuffleString("World!", "Hello "); // > 'Hello do!lrW' (something like this)

Very, very simple random password generator, without using rand() function:<?phpfunction random_password($chars = 8) {   $letters = 'abcefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890';   return substr(str_shuffle($letters), 0, $chars);}?>