Php 登录未正确重定向

我试图在一个网站上登录，它连接到数据库，并对其进行检查，但重定向不起作用（login.php到loggedin.php）。我在校对我自己的代码时表现得非常糟糕，并且已经兜了一段时间圈子了。如果有人能帮助我，我将非常感激！先谢谢你

登录页面&u page.inc.php

<?php # Script 11.1 - login_page.inc.php

// this page prints any errors associated with logging in
//and creates te entire login page, including the fom

//include the header:

$page_title = 'Login';

include ('includes/header.html');

//print any error messages if they exist:

if (!empty($errors)) 
{
echo '<h1>Error!</h1>

<p class="error">The following error(s) occurred:</br>';
foreach ($errors as $msg)
    {
    echo "- $msg</br>\n";
    }
echo '</p><p>Please try again.</p>';
}

//display form
?>
<h1>Login</h1>

    <form action=login.php" method="post">

        <p>Email Address: <input type="text" name="email" size="20" maxlength="80"/></p>

        <p>Password: <input type="password" name="pass" size="20" maxlength="20"/></p>

        <p><input type="submit" name="submit" value="Login"/></p>

        <input type="hidden" name="submitted" value="TRUE"/>

    </form>

<?php //include the footer:

include ('includes/footer.html');

?>

登录
如果任何文件包含发送到浏览器的任何代码，PHP会自动发送所有标题。发送邮件头后，您不能再发送新邮件头，它会删除您的
位置：
邮件头。PHP应该抛出一个通知，在日志中查找它和/或设置正确的
错误报告
标志

这包括换行符或空格，或者在
？>
标记块之后的任何内容。
从我所看到的，您的脚本没有任何问题。。。在这里，但我不确定的内容

includes/header.html
index.php

您还需要更换

不要在标题前包含任何空行（'Location:$url'）。因为这会阻止发送标头，并且您无法重定向到您想要的位置。
问题发生在SHA1与数据库的对话中，其中by SHA1为（40）强，数据库设置为（20）。这是一个恼人的问题，但尚未解决。Var_dump用于与数据库对话，以证明输入的信息是正确的，但它确实显示了数据库中保存的密码是（20），为登录输入的密码是（40）。
确切地说，它是如何工作的？你想重定向到哪里？总导演？或者loggedin.php？哪个重定向失败？如果（$check）
，里面的那一个？您是否验证了
absolute\u url（）
的输出是正确和有效的？loggedin.php是我试图访问的地方。当试图重定向到loggedin时，它告诉我该页面不存在。我一次又一次地浏览，但不明白为什么不会。没有人会读你的代码。你试了什么？你已经把问题孤立出来了吗？错误已经解决了，被否决的票是天才，而那些人显然帮不了忙。感谢所有这样做的人！=）这会阻止loggedin.php被加载吗？目前，我在尝试登录时出现404错误。我在php中没有遇到过这样的错误。对php来说比较新。啊，相关错误！如果你告诉我这些，我只是在猜测发生了什么。您确定两个文件都在同一个案例中吗？目标url正确吗？类Unix的Web服务器往往区分大小写，抱歉！刚刚编辑了它，是的，login和loggedin都在同一个目录文件夹中。同样的大小写：我的意思是像大写或小写。试着查看呈现的源代码，为
login.php
拉出生成的url。这个url有意义吗？文件真的在那个位置吗？这是问题之一（令人尴尬的是，我不擅长校对我自己的东西）。但我现在收到一个错误，说密码和电子邮件不匹配，当我确定它们匹配时（我打开了phpmyadmin，可以看到它们匹配）。我得到“发生了以下错误：-输入的电子邮件地址和密码与文件中的不匹配。”即使电子邮件和密码都是正确的，我可以看到匹配它们的数据库表，所以我不确定出了什么问题？
<?php # loggedin.php

//this is where the user is directed from login.php
session_start(); 
//if no cookie is present redirect the user:
//if (!isset($_COOKIE['user_id']))
if (!isset($_SESSION['user_id']))
{
    //the functions need to create an absolute url
    require_once ('includes/login_functions.inc.php');

    $url = absolute_url();
    header("Location: $url");
    exit(); //exit script
}

//set the page title and include the header
$page_title = 'Logged in.';
include ('includes/header.html');

//welcome message
echo "<h1>Logged in!</h1>
<p>You have successfully logged in, {$_SESSION['first_name']}!</p>

<p><a href=\"logout.php\">Logout</a></p>";

include ('includes/footer.html');

?>

<?php # login.php
//this page processes the login form submission
//upon successful login the user's redirected
//two include files are needed for this
//send nothing to the web browser prior  to the setcookie() lines

//check if  the form has been submitted:
if (isset($_POST['submitted']))
{
    //for processing the login:
    require_once ('includes/login_functions.inc.php');

    //need the database connection:
    require_once ('includes/mysqli_connect.php');

    //check the login
    list ($check, $data) = check_login($dbc, $_POST['email'], $_POST['pass']);

    if($check)
    {
        /*ok, set cookies to last one hour after it is set
        setcookie ('user_id', $data ['user_id'], time()+3600, '/', '', 0, 0);

        setcookie ('first_name', $data ['first_name'], time()+3600, '/', '', 0, 0);*/

        session_start();

        $_SESSION['user_id'] = $data['user_id'];
        $_SESSION['first_name'] = $data['first_name'];

        //redirect
        $url = absolute_url ('loggedin.php');
        header("Location: $url");
        exit(); //quit the script 
    }

    else
    {
        //assign errors to $data for error reporting in the login_page.inc.php
        $errors = $data;
    }

    mysqli_close($dbc); //close the database connection
} //end of main submit condition

include ('includes/login_page.inc.php');



?>

<?php #- login_functions.inc.php

//this page defines two functions used by the login/logout process.

/*this function determines and returns an absolte URL
*takes one argument: the page that concludes the URL
*the arguement defaults to index.php
*/

function absolute_url ($page = 'index.php')
{

//start defining the URL. . .

//URL is http:// plus the host name plus current directory:

$url = 'http://' . $_SERVER['HTTP_HOST'] . dirname($_SERVER['PHP_SELF']);

//remove any trailing slashes:
$url = rtrim($url, '/\\');

//adding the page. . .
$url.= '/' . $page;

//return to the url
return $url;

} //end of the absolute_url function

/* this function validates the form data (the email address and password)

*if both are present the database is queried

*this function requires a database connection

* the function returns an array of information. including:

* - a TRUE or FALSE variable indicating a success or failure
* - an array of either errors or the database return result

*/

function check_login($dbc, $email = '', $pass = '')
{
    $errors = array(); //starting error array

    //validate email address

    if (empty($email))
    {
    $errors[] = 'You forgot to enter your email address.';
    }

    else
    {
    $e = mysqli_real_escape_string($dbc, trim($email));
    }

    //validate the password

    if (empty($pass))
    {
    $errors[] = 'You forgot to enter your password.';
    }

    else
    {
    $p = mysqli_real_escape_string($dbc, trim($pass));
    }

    if (empty($errors))
    {
    /*if everything's okay

    *retrieve the user_id and the first_name for that
    *email+password combination:
    */

    $q = "SELECT user_id, first_name FROM site_users WHERE email='$e' AND pass=SHA1('$p')";

    $r = @mysqli_query ($dbc, $q); //run the query

    //check the result and making sure that both fields are in the same row
    if(mysqli_num_rows($r) ==1)
    {
    //fetch the record
    $row = mysqli_fetch_array ($r, MYSQLI_ASSOC);

    //return true and the record:
    return array(true, $row);
    }

    else
    {
    //not a match
    $errors[] = 'The email address and password entered do not match those on file.';
    }

    }//end of empty($errors) IF.

    //return false and the errors:
    return array(false, $errors);
} //end of check_login() function

?>