PHP Session lost/login not working

Question

I have a question regarding sessions in php. I made a login page, and whenever I tried it, it just gave me a redirect error. So I followed the answer from this question.

So now, instead of getting the redirect error, whenever I press the login button nothing happens, the form is emptied and that is all. What am I doing wrong? This is currently how the code which is giving me issues looks like.

index.php:

    <?phpsession_start();
if (isset($_SESSION['valid_user'])) {

Header("Location: index.php");
exit(); 
}
if (isset($_POST['submit'])) {
$name = $_POST['name'];
$password = $_POST['password'];

$file = file_get_contents("data.txt");
if (strstr($file, "$name||$password")) {


    $_SESSION["valid_user"] = $_POST["name"];
    $_SESSION["valid_time"] = time();


    Header("Location: welcome.php");


} elseif (empty($name) && empty($password)) {

    echo "Both fields are empty. Please fill them.";
} elseif (empty($name)) {

    echo "No name was entered.";
} elseif (empty($password)) {

    echo "No password was entered";
} else {

    echo "Wrong credentials, please try again.";
}
}

To be more specific the code which I think is the problem is this part:

 <?phpsession_start();
if (isset($_SESSION['valid_user'])) {

Header("Location: index.php");
exit(); 
}

But whenever I try it I either get the redirect error:

My browser gives me "ERR_TOO_MANY_REDIRECTS" when I try to enter the page.

or the page just empties the form and nothing else happens. And the error messages which are supposed to be displayed when I don't type anything in the form is not displaying either. It's been giving me headaches the whole day today so if anyone could just point me in the right direction that would be great.

Also the form HTML I use in index.php:

<body>
    <form method="post" action="index.php" >
        <p>Enter name:</p>
        <input type="text" name="name" />
        <br/>
        <br/>
        <p>Enter password:</p>
        <input type="password" name="password" />
        <br/>
        <br/>
        <input type="submit" value="Login" name="submit"/>
    </form>
</body>

well, it shouldn't be like that, there MUST be a space between the php tag and the function. Plus, the lack of the html form that goes with this, doesn't help us. all I can say is: check for errors. too much missing code here. — Funk Forty Niner, Feb 17 '16 at 12:25
my guess; the problem's in the html form you didn't show us, and/or you're outputting before header. again; check for errors. you're not doing that. — Funk Forty Niner, Feb 17 '16 at 12:29
The thing about them changing it to `header` rather than `Header` makes NO difference whatsoever. — Funk Forty Niner, Feb 17 '16 at 12:37
post error which you're getting because I think you're not getting actual error — Kamaldeep singh Bhatia, Feb 17 '16 at 12:40
My browser gives me "ERR_TOO_MANY_REDIRECTS" when I try to enter the page. — Redbird27, Feb 17 '16 at 12:44
seeing your edits: if as you said below *"Adding space gives me the redirect error"* - then you should edit your question with the space for them. It will mislead new visitors to the question who don't know what's going on. Plus, you're stuck in an endless loop, that's what's going on here and also need to put an `exit;` after every header. — Funk Forty Niner, Feb 17 '16 at 12:51
adding space is giving you correct error which actually you should get to correct your code — Kamaldeep singh Bhatia, Feb 17 '16 at 12:55

score 3 · Accepted Answer · edited Feb 17 '16 at 13:21

3

I think there are too many errors related to code. There must be spaces between the opening PHP tag and session_start();.

Plus, the conditional statement you've given in if (isset($_SESSION['valid_user'])) is being interpreted as "if it IS set". What you should have used is the ! operator, meaning if it is "NOT" set.

That is why you are getting "too many redirects".

<?php session_start();// try putting space between here
if (!isset($_SESSION['valid_user'])) {

header("Location: login.php"); // Redirect back to your login page
exit(); 
}

also in } elseif (empty($name) && empty($password)) { // all elseif should be like else if(condition)

also change file names.

You should also add an exit; after every header, otherwise your code will want to continue to execute.

Problem is here when you have a valid user then you are trying to redirect it on index.php which again check for valid user and again redirect on index.php its like INFINITE loop.

Thanx @Fred-ii-

edited Feb 17 '16 at 13:21

Funk Forty Niner

74,450
15
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answered Feb 17 '16 at 12:17

Kamaldeep singh Bhatia

732
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I also feel that the OP should add an `exit;` after all the headers, otherwise their code will want to continue to execute for `Header("Location: welcome.php");` (and every header). We also don't know what's in that (welcome) file. The only way to know for sure, would be to copy their entire code and test it ourselves ;-) – Funk Forty Niner Feb 17 '16 at 13:00
1

Plus, I think the OP meant to do `if (!isset($_SESSION['valid_user']))` as in "if NOT set". Probably the main problem here and wishes to redirect after if it is set and to another page. – Funk Forty Niner Feb 17 '16 at 13:01
you're welcome. However, you need to indicate that in your answer and for future visitors to the question. You're welcome to use my full comment ;-) – Funk Forty Niner Feb 17 '16 at 13:10
1

Thank you guys for helping me and sorry for being very unclear about what the problem was, it is my first post here and I will make sure to be more clear next time, thank you Fred for helping me editing the post! The problem was the infinite loop. – Redbird27 Feb 17 '16 at 13:16
@Redbird27 You're most welcome and was glad to have contributed to a solution, *cheers* – Funk Forty Niner Feb 17 '16 at 13:17

score 0 · Answer 2 · answered Feb 17 '16 at 13:38

You've got your answer but here is an explanation about "Too many redirects". You are getting that error on your browser because your code is keep redirecting to another page. Both of your statements are returning true:

if (isset($_SESSION['valid_user'])) {
} //Returning true - Redirect to index

if (strstr($file, "$name||$password")) {
} //Returning true - Redirect to welcome

As there are/were no exits after the redirects, the code carries on executing: redirect here than redirect there...

Also you should check the session validation as follows:

if(!isset($_SESSION['session']) || $_SESSION[''] == "")

This will check if the session is not set OR empty.

PHP Session lost/login not working

2 Answers2