索引.php导致实时网站上的空警报 - Index.php causing empty alert on live website

所以我有索引.php有我的默认页面。它在 xampp 上工作正常。所以我将我的整个网站上传到1&1（我的域名/托管服务提供商），当我尝试转到我的域名时，我收到一个空警报，没有消息和一个完全空白的页面。

我将文件名更改为索引.html并且网页加载得很好。所以我知道它一定是带有.php扩展或我的代码的东西。

我还添加了一个名为.htaccess的文件，它只包含：

DirectoryIndex index.php

这是我在索引顶部的 php 代码.php（将敏感的信息替换为 *s）：

<?php
//Connect to a database
  $host_name  = "******.db.1and1.com";
  $database   = "db****";
  $user_name  = "dbo******";
  $password   = "***z.0**";
  $connect = mysqli_connect($host_name, $user_name, $password, $database);
  //    echo("nice job");
//Take the values from the html form and assign them to variables
  $ID = $_POST['name'];
  $userpassword = $_POST['password'];
//If no passsowrd entered then go straight to index.php
  echo "<script type='text/javascript'>alert($userpassword);</script>";
  if ($userpassword == null) {
    header("Location: http://localhost:82/index3.php");
    die();
  }
//Check to see if the password matches the hashes
  if (md5($userpassword) === '******************' 
      or md5($userpassword) === '***********' 
      or md5($userpassword) === '****************' 
      or md5($userpassword) === '**************') 
 {
 //Add the visitor name to our list
    mysqli_query($connect, "INSERT INTO `WebsiteVisitors` (`Name`) VALUES  ('$ID')") or die("Error in INSERT: ".mysqli_error($connect));
      //    echo "You have entered the correct password, congrats.";
  // Start the session so they can access other pages
    session_start();
    $_SESSION['loggedIn'] = true;
  // Redirect them to rest of site
    header("Location: http://localhost:82/home.php");
    die();
   }
    else {
    header("Refresh: 0; url=index2.php");
    echo "<script type='text/javascript'>alert('"Wrong Password. Check your     invitation card.'");</script>";
  }
  ?>

由于$_POST请求仅在您的情况下提交表单后才出现，因此您只需在存在$_POST["name"]和$_POST["password"]时才执行用户名和密码检查。

因此，在使用

和操作变量之前给出一个 if 语句if(isset($_POST['name']) && isset($_POST['password'])) $_POST。此外，session_start()应该在脚本的顶部给出。

以下是您的完整代码，包括检查

<?php
session_start();
// session start should be at top of your script
error_reporting(E_ERROR); // reports only errors
//Connect to a database
$host_name  = "******.db.1and1.com";
$database   = "db****";
$user_name  = "dbo******";
$password   = "***z.0**";
$connect = mysqli_connect($host_name, $user_name, $password, $database);
// $_POST request comes only when form is submitted in your case. So check for $_POST['name'] and $_POST['password']
if(isset($_POST['name']) && isset($_POST['password'])) 
{
        $ID = $_POST['name'];
        $userpassword = $_POST['password'];
        //If no passsowrd entered then go straight to index.php
        if ($userpassword == null)
        {
                echo "<script type='text/javascript'>alert("Empty Password");</script>";
                header("Location: http://localhost:82/index3.php");
                die();
        }
        //Check to see if the password matches the hashes
        if (md5($userpassword) === '******************' 
                  or md5($userpassword) === '***********' 
                  or md5($userpassword) === '****************' 
                  or md5($userpassword) === '**************') 
       {
             //Add the visitor name to our list
             mysqli_query($connect, "INSERT INTO `WebsiteVisitors` (`Name`) VALUES  ('$ID')") or die("Error in INSERT: ".mysqli_error($connect));
              $_SESSION['loggedIn'] = true;
              // Redirect them to rest of site
              header("Location: http://localhost:82/home.php");
              die();
         }
         else
         {
               echo "<script type='text/javascript'>alert('"Wrong Password. Check your     invitation card.'");</script>";
               header("Refresh: 0; url=index2.php");
        }
  }
  ?>