str_shuffle

(PHP 4 >= 4.3.0, PHP 5)

str_shuffle -- Randomly shuffles a string

Description

string str_shuffle ( string str )

str_shuffle() shuffles a string. One permutation of all possible is created.

例子 1. str_shuffle() example

<?php
$str
= 'abcdef';
$shuffled = str_shuffle($str);

// This will echo something like: bfdaec
echo $shuffled;
?>

See also shuffle() and rand().


add a note add a note User Contributed Notes
nmoyroud at teledetection dot fr
03-Nov-2005 08:38
Just another update to password builder function. With this version, you can choose the number of alphanumeric characters to add and the number of non-alphanumeric characters. You obtain a more secure password. You can add another characters to the non-alphanumeric list if you need.
If you want a password with 8 alphanumeric and 3 non-alphanumeric characters in a random order, just call :
random_passwd(8,3);

function generatePasswd($numAlpha=6,$numNonAlpha=2) {
   $pwd = '';
   $listAlpha = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';
   $listNonAlpha = ',;:!?.$/*-+&@_+;./*&?$-!,';

   $start = mt_rand(1, (strlen($listAlpha)-$numAlpha));
   $string = str_shuffle($listAlpha);
   $pwd .= substr($string,$start,$numAlpha);

   $start = mt_rand(1, (strlen($listNonAlpha)-$numNonAlpha));
   $string = str_shuffle($listNonAlpha);
   $pwd .= substr($string,$start,$numNonAlpha);

   return str_shuffle($pwd);
}
support at wiredlabs dot net
16-Aug-2005 05:03
Just an update to sfalcon's function.  Chooses a random number within the length and then selects a random segment not the current segment of 1 to $numchar. Also added upper-case chars.

function random_passwd($numchar=8) {
   $str = "abcefghijklmnopqrstuvwxyz1234567890ABCDEFGHIJKLMNOPQRSTUVWXYZ";
   $start = mt_rand(1, (strlen($str)-$numchar));
   $string = str_shuffle($str);
   $password = substr($string,$start,$numchar);
   return($password);
}
Qube, Efnet #php
05-Aug-2005 07:20
(correction)
I balked at the loop method used below in inverting and randomising capitalisation and released that we just need to flip the bit (3rd bit or 6th depending on what way you look at it) and it would cause the case change in a character.

Full code and example:
http://www.pgregg.com/projects/php/code/str_case.php
(append an s to the url to get the .phps source)

I came up with a method and thanks to arpad (optimising as ever! :) we now have:

Invert case:
preg_replace('/[a-z]/ie', '\'$0\' ^ str_pad(\'\', strlen(\'$0\'), \' \')', $input);

Randomise case:
preg_replace('/[a-z]/ie', '(rand(0,1) ? \'$0\' ^ str_pad(\'\', strlen(\'$0\'), \' \') : \'$0\')', $input);

and for good measure:
Upper case:
preg_replace('/[a-z]/e', '\'$0\' & str_pad(\'\', strlen(\'$0\'), chr(223))', $input);

Lower case:
preg_replace('/[A-Z]/e', '\'$0\' | str_pad(\'\', strlen(\'$0\'), \' \')', $input);
rudigreen at gmail dot com
02-Jul-2005 10:20
Here are 2 functions, one inverts the case of a string and the other one randomizes the captilization in a string, kinda
useful string operations.

<?

//Inverts the case of a string
function invert_case($str)
{
  
$nstr = '';
   for(
$i=0;$i<strlen($str);$i++)
   {
      
$char = substr($str,$i,1);
      
//If it's lower case make it upper case
      
if($char == strtolower($char))
       {
          
$char = strtoupper($char);
       }
       else
//if it's upper than make it lower
      
{
          
$char = strtolower($char);
       }
      
$nstr .= $char;
   }
   return
$nstr;
}

//Randomly capilizes/uncaptilizes chars in a string
function rand_case($str)
{
  
$nstr = '';
   for(
$i=0;$i<strlen($str);$i++)
   {
      
$char = substr($str,$i,1);
      
$char = invert_case($char);
      
//2 options, to change or not to change
      
rand(0,1) == 1 ? $char = invert_case($char) : null;
      
$nstr .= $char;
   }
   return
$nstr;
}

//Example:
echo rand_case("pHp rooLz! gUyZ"); //produces something random
echo invert_case("pHP STRiNG sEx");//produces Php strIng SeX
?>
Michiel van den boogaard
17-Jan-2005 06:03
Shortend function for PHP < 4.3
<?php 
function RandomPass($numchar

  
$word = "a,b,c,d,e,f,g,h,i,j,k,l,m,1,2,3,4,5,6,7,8,9,0"
  
$array=explode(",",$word); 
  
shuffle($array); 
  
$newstring = implode($array,""); 
   return
substr($newstring, 0, $numchar); 

?>
aidan at php dot net
27-Aug-2004 06:31
This functionality is now implemented in the PEAR package PHP_Compat.

More information about using this function without upgrading your version of PHP can be found on the below link:

http://pear.php.net/package/PHP_Compat
sfalcon_(at)_pymesweb_(dot)_com
26-Aug-2004 11:28
You can use str_shuffle to make simple and nice random passwords:

function random_passwd($numchar) {
     $string =str_shuffle("abcefghijklmnopqrstuvwxyz1234567890");
     $password = substr($string,1,$numchar);

     return($password);
}

echo random_passwd('8') // Will return something like "xa3dh214" =)