利用cookie实现用户自动登录的代码

cookie 是由服务器发送到浏览器的变量。cookie 通常是服务器嵌入到用户计算机中的小文本文件。每当计算机通过浏览器请求一个页面，就会发送这个 cookie。

实例

  echo( "Cookie created? : " . setcookie("cookie_name", "cookie_data" ) );

?>

 

 
 

 

 

如果要删除 cookie只要设置cookie的过期时间就行了，
实例

setcookie ( "cookie_user", "test", time () + 60 * 60 * 24 * 30 );
setcookie ( "cookie_pass", md5 ( "test" ), time () + 60 * 60 * 24 * 30 );

function logout() {
  setcookie ( "cookie_user", "", time () + 60 * 60 * 24 * 30 );
  setcookie ( "cookie_pass", "", time () + 60 * 60 * 24 * 30 );
}
logout ();
echo $_COOKIE ['cookie_user'] . "
";
echo "You have successfully logged out.";
?>

我们在开发中经常会用到cookie自动登录

实例

  $GLOBALS['username'] = "test";
  $GLOBALS['password'] = "test";
 
  function validatelogin ($username, $password){
    if (strcmp ($username, $GLOBALS['username']) == 0 && strcmp ($password, $GLOBALS['password']) == 0){
      setcookie ("cookie_user", $username, time()+60*60*24*30);
      setcookie ("cookie_pass", md5 ($password), time()+60*60*24*30);
      return true;
    } else {
      return false;
    }
  }
  if (validatelogin ("test","test")){
    echo "Successfully logged in.";
  } else {
    echo "Sorry, invalid login.";
  }
?>