php随机密码生成的自定义函数,生成sessionid和随机密码的例子

        //,  if (is

用这个可以来验证用户和生成随机密码–teaman
<?
        //—————————————————-
        // Function GetSID()
        //
        // Parameters : $nSize number of caracters, default 24
        // Return value : 24 caracters string
        //
        // Description : This function returns a random string
        // of 24 caracters that can be used to identify users
        // on your web site in a more secure way. You can also  
        // use this function to generate passwords.
        //—————————————————-
        function GetSID ($nSize=24) {

可以指定生成的字符串长度

            // Randomize
            mt_srand ((double) microtime() * 1000000);
            for ($i=1; $i<=$nSize; $i++) {

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;
}
调用实例:
$randstr = rand_str(16);

                // if you wish to add numbers in your string,  
                // uncomment the two lines that are commented
                // in the if statement
                $nRandom = mt_rand(1,30);
                if ($nRandom <= 10) {
                    // Uppercase letters
                    $sessionID .= chr(mt_rand(65,90));
            //    } elseif ($nRandom <= 20) {
            //        $sessionID .= mt_rand(0,9);
                } else {
                    // Lowercase letters
                    $sessionID .= chr(mt_rand(97,122));
                }

生成随机字符串的函数

            }         
            return $sessionID;
        }
        // Test the function  
        echo GetSID(16);
    ?> 

<?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=’ABDEFGHJKLMNPQRSTVWXYabdefghijkmnpqrstvwxy23456789#%*’; //
characters to build the password from
mt_srand((double)microtime()*1000000*getmypid()); // seed the random
number generater (must be done)
$password=”;
while(strlen($password)<$len)
$password.=substr($chars,(mt_rand()%strlen($chars)),1);
return $password;
}
?>

创建字符池。

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);

无需创建字符池  
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);

随机用户名和随机密码例子

//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
    $chars =
‘abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789!@#$%^&*()-_
[]{}<>~`+=,.;:/?|’;
    $password = ”;
    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 = ‘user’.generate_username(6);
$pwd = create_password(9);

mt_srand生成随机种子,密码的长度可以随意定义,最长32位。

<?php
mt_srand((double) microtime() * 1000000);
 
function gen_random_password($password_length = 32,
$generated_password = “”){
 $valid_characters =
“abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789”;
 $chars_length = strlen($valid_characters) – 1;
 for($i = $password_length; $i–; ) {
  //$generated_password .= $valid_characters[mt_rand(0,
$chars_length)];
 
  $generated_password .= substr($valid_characters,
(mt_rand()%(strlen($valid_characters))), 1);
 }
 return $generated_password;
}
?>
<!DOCTYPE HTML PUBLIC “-//W3C//DTD HTML 4.01 Transitional//EN”
“;
<html>
<head>
<title>php密码生成器</title>
<style type=”text/css”>
body {
 font-family: Arial;
 font-size: 10pt;
}
</style>
</head>
<body>
<span style=”font-weight: bold; font-size:
15pt;”>密码生成器</span><br /><br />
<?php
 
if (isset($_GET[‘password_length’])){
 if(preg_match(“/([0-9]{1,8})/”,
$_GET[‘password_length’])){
  print(“密码生成成功:<br />
<span style=”font-weight: bold”>” .
gen_random_password($_GET[‘password_length’]) .
“</span><br /><br />n”);
 } else {
  print(“密码长度不正确!<br /><br />n”);
 }
}
 
print <<< end
请为密码生成其指定生成密码的长度:<br /><br />
<form action=”{$_SERVER[‘PHP_SELF’]}” method=”get”>
 <input type=”text” name=”password_length”>
 <input type=”submit” value=”生成”>
</form>
end;
?>
</body>
</html>