A login class in php [recommended]_PHP tutorial

PHP code:
/*
* Name: CnkknD PHP Login Class
* Description: PHP class used for login, based on MySQL
* Author: Daniel King, cnkknd@ 163.com
* Date: 2003/8/25
*/

class Login
{
var $username; //Username
var $userpass; / /Password
var $userid; //User id
var $userlevel; //User level

var $authtable="account"; //Verification data table

var $usecookie=true; //Use cookie to save sessionid
var $cookiepath='/'; //Cookie path
var $cookietime=108000; //Cookie validity time

var $err_mysql ="mysql error"; //mysql error prompt
var $err_username="username invalid"; //user name invalid prompt
var $err_user="user invalid"; //user invalid prompt (banned)
var $err_password="password error"; //Password error prompt

var $err; //Error prompt

var $errorreport=false; //Display error

function Login($dbserv,$dbport,$dbuser,$dbpass,$dbname) //Constructor, connect to the database
{
if(@mysql_pconnect($dbserv.":".$dbport, $dbuser,$dbpass))
{
mysql_select_db($dbname);
}
else
{
$this->errReport($this->err_mysql);
$this->err=$this->err_mysql;
}
}

function isLoggedin() //Determine whether to log in
{
if(isset ($_COOKIE['sid'])) //If there is sid saved in the cookie
{
session_id($_COOKIE['sid']);
session_start();
$this-> ;username=$_SESSION['username'];
$this->userid=$_SESSION['userid'];
$this->userlevel=$_SESSION['userlevel'];
return true;
}
else //If the sid is not saved in the cookie, check the session directly
{
session_start();
if(isset($_SESSION['username']) )
return true;
}
return false;
}

function userAuth($username,$userpass) //User authentication
{
$this- >username=$username;
$this->userpass=$userpass;
$query="select * from `".$this->authtable."` where `username`='$username ';";
$result=mysql_query($query);
if(mysql_num_rows($result)!=0) //Find this user
{
$row=mysql_fetch_array($result) ;
if($row['bannd']==1) //This user is banned
{
$this->errReport($this->err_user);
$this ->err=$this->err_user;
return false;
}
elseif(md5($userpass)==$row['userpass']) //Password matching
{
$this->userid=$row['id'];
$this->userlevel=$row['userlevel'];
return true;
}
else //Password mismatch
{
$this->errReport($this->err_password);
$this->err=$this->err_password;
return false;
}
}
else //This user was not found
{
$this->errReport($this->err_username);
$this->err= $this->err_username;
return false;
}
}

function setSession() //Set session
{
$sid=uniqid('sid' ); //Generate sid
session_id($sid);
session_start();
$_SESSION['username']=$this->username; //Assign value to session variable
$ _SESSION['userid']=$this->userid; //..
$_SESSION['userlevel']=$this->userlevel; //..
if($this-> use_cookie) //If you use cookies to save sid
{
if(!setcookie('sid',$sid,time()+$this->cookietime,$this->cookiepath))
$this->errReport("set cookie failed");
}
else
setcookie('sid','',time()-3600); //Clear the sid in the cookie
}

function userLogout() //User logout
{
session_start();
unset($_SESSION['username']); //Clear username in session
if(setcookie('sid','',time()-3600))
//Clear the sid in the cookie
return true;
else
return false;
}

function errReport($str) //Error reporting
{
if($this->error_report)
echo "ERROR: $str";
}
}
?> 

mysql中表的结构


代码:
CREATE TABLE `account` (
  `id` bigint(20) NOT NULL auto_increment,
  `username` varchar(255) NOT NULL default '',
  `userpass` varchar(255) NOT NULL default '',
  `banned` tinyint(1) NOT NULL default '0',
  `userlevel` tinyint(4) NOT NULL default '0',
  PRIMARY KEY  (`id`)
) 


使用一例


PHP代码:
include "../myclasses/Login.php";
$dbserv="localhost";
$dbport="3306";
$dbuser="root";
$dbpass="123456";
$dbname="test";

$login=new Login($dbserv,$dbport,$dbuser,$dbpass,$dbname);
$login->error_report=true;
$login->cookietime=3600*24*30;
if($login->isLoggedin())
{
echo $login->username." has aready logged in";
}
elseif($login->userAuth("danielking","1234"))
{
echo "login successfully";
$login->setSession();
}

echo "

...