임의의 비밀번호 예제를 생성하는 PHP 사용자 정의 기능에 대한 자세한 설명

function rand_str($length, $max=FALSE) 
{ 
  if (is_int($max) && $max > $length) 
  { 
    $length = mt_rand($length, $max); 
  } 
  $output = ''; 
    
  for ($i=0; $i<$length; $i++) 
  { 
    $which = mt_rand(0,2); 
      
    if ($which === 0) 
    { 
      $output .= mt_rand(0,9); 
    } 
    elseif ($which === 1) 
    { 
      $output .= chr(mt_rand(65,90)); 
    } 
    else 
    { 
      $output .= chr(mt_rand(97,122)); 
    } 
  } 
  return $output; 
}

<?php 
/** 
* 产生随机字符串 
* 
* 产生一个指定长度的随机字符串,并返回给用户 
* 
* @access public 
* @param int $len 产生字符串的位数 
* @return string 
*/ 
function randStr($len=6) { 
$chars=&#39;ABDEFGHJKLMNPQRSTVWXYabdefghijkmnpqrstvwxy23456789#%*&#39;; // characters to build the password from 
mt_srand((double)microtime()*1000000*getmypid()); // seed the random number generater (must be done) 
$password=&#39;&#39;;
while(strlen($password)<$len) 
$password.=substr($chars,(mt_rand()%strlen($chars)),1); 
return $password; 
} 
?>

function randomkeys($length) 
   { 
       $pattern = '1234567890abcdefghijklmnopqrstuvwxyz 
                   ABCDEFGHIJKLOMNOPQRSTUVWXYZ,./&l 
                  t;>?;#:@~[]{}-_=+)(*&^%$?!';    //字符池 
      for($i=0; $i<$length; $i++) 
       { 
           $key .= $pattern{mt_rand(0,35)};    //生成php随机数 
       } 
       return $key; 
   } 
   echo randomkeys(8);

function randomkeys($length) 
   { 
        $output=''; 
        for ($a = 0; $a < $length; $a++) { 
            $output .= chr(mt_rand(35, 126));    //生成php随机数 
        } 
        return $output; 
    } 
    echo randomkeys(8);

//随机生成用户名(长度6-13)  
 
function create_password($pw_length = 4){  
    $randpwd = '';  
    for ($i = 0; $i < $pw_length; $i++){  
        $randpwd .= chr(mt_rand(33, 126));  
    }  
    return $randpwd;  
} 
 
function generate_username( $length = 6 ) {  
    // 密码字符集，可任意添加你需要的字符  
    $chars = &#39;abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!@#$%^&*()-_ []{}<>~`+=,.;:/?|&#39;;  
    $password = &#39;&#39;;  
    for ( $i = 0; $i < $length; $i++ )  
    {  
        // 这里提供两种字符获取方式  
        // 第一种是使用substr 截取$chars中的任意一位字符；  
        // 第二种是取字符数组$chars 的任意元素  
        // $password .= substr($chars, mt_rand(0, strlen($chars) - 1), 1);  
        $password .= $chars[ mt_rand(0, strlen($chars) - 1) ];  
    }  
    return $password;  
} 
//调用 
$userId = &#39;user&#39;.generate_username(6);  
$pwd = create_password(9);