PHP:如何检查用户是否已经登录，否则重定向到登录页面 [英] PHP: How to check if user is already logged in and otherwise redirect to login page
问题描述
我是PHP的新手，并且在以下方面苦苦挣扎:
I am new to PHP and am struggling with the following:
我有一个页面，我想在此页面上检查某人是否为注册用户，然后让他们查看该网站的内容.
所以我的想法是，在我的头文件(通过require_once("includes/header.php");在所有单个页面上引用)中，如果它们尚未登录，则可以对其进行检查并将其重定向到登录页面(login.php).
I have a page where I want to check if someone is a registered user before letting them see the content of the site.
So my thought was that in my header file (which is referenced on all single pages via require_once("includes/header.php");) I can check on that and redirect them to a login page (login.php) if they have not logged yet.
这就是标题中的所有内容:
<!DOCTYPE html>
<html>
<head>
<?php
define("someUnguessableVariable", "anotherUnguessableVariable");
session_start();
if(!(isset($_SESSION['login']) && $_SESSION['login'] != '')){
header ("Location: login.php");
}
include "system/config.php";
$pageURL = basename($_SERVER["REQUEST_URI"]);
$pageName = pathinfo(parse_url($pageURL, PHP_URL_PATH), PATHINFO_FILENAME);
$selectedLang = $_GET["lang"];
if(!isset($selectedLang)){
$selectedLang = "de";
}
$langURL = "?lang=" . $selectedLang;
$conn = new mysqli($dbServer, $dbUser, $dbPass, $dbName);
$conn->set_charset("utf8");
if($conn->connect_error){
die("Connection failed: " . $conn->connect_error);
}
// fetch main translations
$location = "%main%";
$stmt = $conn->prepare("SELECT tID, " . $selectedLang . " FROM TranslationsMain WHERE location LIKE ? ORDER BY tID");
$stmt->bind_param("s", $location);
$stmt->execute();
$result = $stmt->get_result();
while($arrTranslations = $result->fetch_assoc()){
$trans[] = array("ID" => $arrTranslations["tID"], "trans" => $arrTranslations[$selectedLang]);
}
$conn->close();
// get main translations by ID
function fetchTransMain($trans, $itemID){
foreach($trans as $key => $val){
if($val["ID"] == $itemID){
return $val["trans"];
}
}
}
?>
<meta charset="utf-8" />
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<meta name="author" content="Some author" />
<meta name="description" content="Created: 2015-06" />
<base href="http://www.myurl.de" target="_self" />
<title>Some title</title>
<!-- CSS -->
<link rel="stylesheet" type="text/css" href="includes/styles.css" />
<!-- CSS - Font Awesome -->
<link rel="stylesheet" type="text/css" href="http://maxcdn.bootstrapcdn.com/font-awesome/4.3.0/css/font-awesome.min.css" />
<!-- include favicon -->
<link rel="shortcut icon" href="images/favicon/favicon.ico" type="image/x-icon" />
<link rel="icon" href="images/favicon/favicon.png" type="image/png" />
<link rel="icon" sizes="32x32" href="images/favicon/favicon-32.png" type="image/png" />
<link rel="icon" sizes="64x64" href="images/favicon/favicon-64.png" type="image/png" />
<link rel="icon" sizes="96x96" href="images/favicon/favicon-96.png" type="image/png" />
<link rel="icon" sizes="196x196" href="images/favicon/favicon-196.png" type="image/png" />
<link rel="apple-touch-icon" sizes="152x152" href="images/favicon/apple-touch-icon.png" />
<link rel="apple-touch-icon" sizes="60x60" href="images/favicon/apple-touch-icon-60x60.png" />
<link rel="apple-touch-icon" sizes="76x76" href="images/favicon/apple-touch-icon-76x76.png" />
<link rel="apple-touch-icon" sizes="114x114" href="images/favicon/apple-touch-icon-114x114.png" />
<link rel="apple-touch-icon" sizes="120x120" href="images/favicon/apple-touch-icon-120x120.png" />
<link rel="apple-touch-icon" sizes="144x144" href="images/favicon/apple-touch-icon-144x144.png" />
<meta name="msapplication-TileImage" content="favicon-144.png" />
<meta name="msapplication-TileColor" content="#ffffff" />
<script>
var baseURL = '<?php echo $baseURL; ?>';
var pageURL = '<?php echo $pageURL; ?>';
var pageName = '<?php echo $pageName; ?>';
var selectedLang = '<?php echo $selectedLang; ?>';
</script>
</head>
<body>
现在这行不通了，我想我可能缺少了几件事，但是我找不到关于它的好的教程或指南. 另外，我不确定是否需要执行其他任何操作来启动和设置会话.
Now this is not working and I think I am probably missing a couple of things but I couldn't find a good tutorial or guideline on that. Also, I am not sure if there is anything else I need to do in order to start and set up the session.
有人可以帮我吗?
注意:
这仅用于检查用户是否已经登录，因为所有实际的用户注册和验证都是在单独的登录页面上完成的，为此，我已经使用了代码.
Note:
This is only about checking if a user is already logged in since all the actual user registration and verification is done on the separate login page and for this I already have the code working.
更新: 启用错误消息将返回以下错误:
Update: Enabling error messages returns the following errors:
Warning: session_start(): Cannot send session cookie - headers already sent by (output started at /homepages/21/d580042014/htdocs/index.php:2) in /homepages/21/d580042014/htdocs/includes/header.php on line 9
Warning: session_start(): Cannot send session cache limiter - headers already sent (output started at /homepages/21/d580042014/htdocs/index.php:2) in /homepages/21/d580042014/htdocs/includes/header.php on line 9
array(0) { }
Warning: Cannot modify header information - headers already sent by (output started at /homepages/21/d580042014/htdocs/index.php:2) in /homepages/21/d580042014/htdocs/includes/header.php on line 12
Notice: Undefined index: lang in /homepages/21/d580042014/htdocs/includes/header.php on line 18
更新:
根据评论，我现在发布了标头中当前的所有内容.
Update:
As per the comments I now posted everything that's currently in the header.
非常感谢.
推荐答案
更新:该问题已在根据您的修改，更改此块:
As per your edit, change this block:
<!DOCTYPE html>
<html>
<head>
<?php
define("someUnguessableVariable", "anotherUnguessableVariable");
session_start();
if(!(isset($_SESSION['login']) && $_SESSION['login'] != '')){
header ("Location: login.php");
}
收件人:
<?php
session_start();
?>
<!DOCTYPE html>
<html>
<head>
<?php
define("someUnguessableVariable", "anotherUnguessableVariable");
if(!isset($_SESSION['login']) && $_SESSION['login'] != ''){
header ("Location: login.php");
exit; // stop further executing, very important
}
- 在使用会话的所有文件中遵循相同的结构来启动会话.
- 确保您的文件没有字节顺序标记(BOM).
-
<?php等之前没有空格.这已在注释中建立. - Follow the same structure for starting the session in all your files using sessions.
- Make sure that your file does not have a byte order mark (BOM).
- No space before
<?phpetc. this has already been established in comments.
使用诸如Notepad ++之类的代码编辑器 https://notepad-plus-plus.org/并将其保存为不带BOM的UTF-8，这将确保没有字节顺序标记.
Using a code editor such as Notepad++ https://notepad-plus-plus.org/ and to save it as UTF-8 without BOM which will ensure there is no byte order mark.
此外，使用新方法进行会话数组检查.
Also, using the new method for your sessions array check.
if(!isset($_SESSION['login']) && $_SESSION['login'] != ''){
还要检查以确保没有任何包含/必需的文件具有相同的问题，包括login.php.
Also check to see that none of your included/required files have the same issues, including login.php.
脚注:
在Notepad ++的下拉菜单中，您将看到
Inside Notepad++'s dropdown menu, you will see
- 编码.它将显示当前文件的编码设置.
如果确实显示了字节顺序标记，请按照下列步骤操作:
If it does show a byte order mark, follow these steps:
- 单击编码".
- 转换为不带BOM的UTF-8
-
保存文件.
- Click on "Encoding".
- Convert to UTF-8 without BOM
Save the file.
- 对所有文件执行此操作.
参考文献:
Reference(s):
旁注:
您应将$stmt->execute();更改为
if(!$stmt->execute()){
trigger_error("there was an error....".$conn->error, E_USER_WARNING);
}
- 最好在查询中捕获可能的错误.
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