PHP header function is not working

Question

The following header function is not working. I ma trying to go to login if the user is not logged in -

    <?PHP
    if (logged_in() === false) {
    header('Location: login.php');
    }
    ?>

However if I do -

    <?PHP
    if (logged_in() === false) {
    echo"No user is logged in";
    }
    ?>

It does echo it and I can see that it says no user is logged in

It is basically just checking if there is a user logged in

    function logged_in() {
    return (isset($_SESSION['user_id'])) ? true : false;
    }

**wild guess**, `logged_in()` does some output, and `header()` then issue a warning and doesn't work — , Jun 07 '13 at 05:14
Agree with the earlier request for more info about logged_in(). Would you please update the question to include that function? — Thomas, Jun 07 '13 at 05:14
You need to include `session_start();` as your first line of code after ` — Funk Forty Niner, Jun 07 '13 at 05:23
It worked I needed the ob_start and on_end_flush. Thanks a lot everyone for the help — avink, Jun 07 '13 at 05:31
@Fasilkk You should get the credit for this. Post it as an answer and I'll upvote it. — Funk Forty Niner, Jun 07 '13 at 05:43
possible duplicate of [Headers already sent by PHP](http://stackoverflow.com/questions/8028957/headers-already-sent-by-php) — deceze, Jul 03 '13 at 06:22
@Fasil Output buffering is fixing the symptoms, not the problem. Read http://stackoverflow.com/a/8028987/476. — deceze, Jul 03 '13 at 06:48
@deceze I also mentioned that, "Make sure that there is no output(white-space also) in your code" — Fasil kk, Jul 03 '13 at 10:37

GautamD31 · Answer 1 · 2013-06-07T05:27:34.740

2

Try to put exit() or die() after the header like

  if (logged_in() === false) {
      header('Location: login.php');
      exit();    //or die();
  }

But makesure that your login.php should be in the same folder

edited Jun 07 '13 at 05:27

answered Jun 07 '13 at 05:15

GautamD31

28,552
10
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Thanks for the help. I figured it out I needed the ob_start and ob_end_flush – avink Jun 07 '13 at 05:32
@AvinashKunaparaju *Ahem*, `Fasil kk` figured it out ;-) – Funk Forty Niner Jun 07 '13 at 05:36

Fasil kk · Answer 2 · 2013-07-03T05:38:36.417

1

Make sure that there is no output(white-space also) in your code.

you can use ob_start() and ob_end_flush() to clear out-put.

<?php ob_start();

 // code 

ob_end_flush(); ?>

edited Jul 03 '13 at 05:38

answered Jun 07 '13 at 05:45

Fasil kk

2,147
17
26

Although this solved the problem, it'd be good to explain why, for future visitors viewing this question. – Daedalus Jun 07 '13 at 05:45
@Daedalus Like 90% of the questions with answers on SO, most post a link to PHP.net anyway, so it's irrelevant. Give the guy a break. – Funk Forty Niner Jun 07 '13 at 05:48
@Daedalus... I added small explanation too.. I think that is enough to understand for all. – Fasil kk Jun 07 '13 at 06:44

score 0 · Answer 3 · answered Jun 07 '13 at 05:23

You probably need to include the fully qualified domain and path to the new url. There is a note on the official documentation for the header function indicating as such.

Note:

HTTP/1.1 requires an absolute URI as argument to » Location: including the scheme, hostname and absolute path, but some clients accept relative URIs. You can usually use $_SERVER['HTTP_HOST'], $_SERVER['PHP_SELF'] and dirname() to make an absolute URI from a relative one yourself:

This note also contains the following code sample.

<?php 
/* Redirect to a different page in the current directory that was requested */ 
$host  = $_SERVER['HTTP_HOST']; 
$uri   = rtrim(dirname($_SERVER['PHP_SELF']), '/\\'); 
$extra = 'login.php';
header("Location: http://$host$uri/$extra"); 
exit; 
?>

Every browser supports relative URLs, and W3C or IETF is planning on changing the spec to say that it's allowed. — Barmar, Jun 07 '13 at 05:25
See http://stackoverflow.com/questions/8250259/is-a-302-redirect-to-relative-url-valid-or-invalid — Barmar, Jun 07 '13 at 05:26

PHP header function is not working

3 Answers3