logout page error session

Question

I'm having a little problem when I try to logout

    <?php
session_start();
session_unset();

session_destroy();
header("location:../");
?>

this is my logout code, and that is the error:

Warning: session_start() [function.session-start]: Cannot send session cache limiter - headers already sent (output started at /home1/jota/public_html/adm/logout.php:1) in /home1/jota/public_html/adm/logout.php on line 2

Warning: Cannot modify header information - headers already sent by (output started at /home1/jota/public_html/adm/logout.php:1) in /home1/jota/public_html/adm/logout.php on line 6

Can't have whitespace or any output before ` – Wesley Murch Sep 15 '13 at 17:24 — Wesley Murch, Sep 15 '13 at 17:24

score 0 · Answer 1 · answered Sep 15 '13 at 17:25

There appears to be some whitespace in front of your opening <?php tag. Remove it, so there is no characters before it, and it should work fine.

Alternatively, you could enable output caching by calling ob_start() at the start of your script, or by changing the output_buffering variable in your php.ini file to 1. (Note this will enable it for EVERY PHP file on your server -- you may wish to instead do it in a .htaccess file for the directory your code is in.)

No don't do the output buffering thing. – Wesley Murch Sep 15 '13 at 17:29 — Wesley Murch, Sep 15 '13 at 17:29

score 0 · Answer 2 · answered Sep 15 '13 at 17:28

0

As @Wesley Murch said in his comment , you have a white space in the beginning of your page ,as in php documentation

To use cookie-based sessions, session_start() must be called before outputing anything to the browser.

You are outputing white spaces here.

answered Sep 15 '13 at 17:28

Charaf JRA

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No don't do the redirect in javascript. Besides, you'll still get the same error. The fix is simple: no output before headers. – Wesley Murch Sep 15 '13 at 17:30
`session_start()` and `session_destroy()` can also output headers, so your suggestion would not solve the root cause of this issue. Users may also have JavaScript disabled. – Tristan Sep 15 '13 at 17:30
@TristanSeifert i agree , ideleted the javascript part because session also output header – Charaf JRA Sep 15 '13 at 17:33
may be BOM issue. you really can't say whitespace for sure. – itachi Sep 15 '13 at 18:34

logout page error session

2 Answers2