php登录与退出登录实例代码_PHP教程

function showPage() //判断是否登录 未登录直接跳转至登录页面
{
if(!isset($_SESSION["user"]) && !isset($_SESSION["pwd"]))
{
if(isset($_COOKIE["user"]) && isset($_COOKIE["pwd"]))
{
$sql = "select * from pm_user where u_user='$_COOKIE[user]'";
$query = mysql_query($sql);
$isUser = is_array($row = mysql_fetch_array($query)); //判断用户名
$isPwd = $isUser ? $row["u_pwd"] == $_COOKIE["pwd"] : false; //判断密码
if($isPwd)
{
$_SESSION["user"] = $_COOKIE["user"];
$_SESSION["pwd"] = $_COOKIE["pwd"];
$_SESSION["id"] = $_COOKIE["id"];
$_SESSION["name"] = $_COOKIE["name"];
}
}
}

if(!isset($_SESSION["user"]) && !isset($_SESSION["pwd"]))
{
echo '';
exit();
}
}

function loginOut() //登出函数
{
if(isset($_GET["login"]) == 'out')
{
$_SESSION["user"] = '';
$_SESSION["pwd"] = '';
$_SESSION["id"] = '';
$_SESSION["name"] = '';
session_destroy();
echo '';
}
}