可以指定生成的字符串长度
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);
生成随机字符串的函数
/**
* 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);
$pwd = create_password(9);
mt_srand生成随机种子,密码的长度可以随意定义,最长32位。
mt_srand((double) microtime() * 1000000);
function gen_random_password($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;
}
?>