PHP header warnings... why?

Question

When I return to my site after a period of time -like a few hours - I get 3 PHP warnings like in the screenshot for some reason. When I login/logout, the warnings go away.

enter image description here

[phpBB Debug] PHP Warning: in file [ROOT]/includes/session.php on line 1042: Cannot modify header information - headers already sent by (output started at /home/content/60/11957760/html/runicparadise/index.php:22) [phpBB Debug] PHP Warning: in file [ROOT]/includes/session.php on line 1042: Cannot modify header information - headers already sent by (output started at /home/content/60/11957760/html/runicparadise/index.php:22) [phpBB Debug] PHP Warning: in file [ROOT]/includes/session.php on line 1042: Cannot modify header information - headers already sent by (output started at /home/content/60/11957760/html/runicparadise/index.php:22)

This is the php code from line 22 it's referring to... the other reference seems to be somewhere on my host's server I guess?

<?php 
define('IN_PHPBB', true); 
$phpbb_root_path = './forums/'; 
$phpEx = substr(strrchr(__FILE__, '.'), 1); 
include($phpbb_root_path . 'common.' . $phpEx); 
// Start session management 
$user->session_begin(); 
$auth->acl($user->data); 
$user->setup(); 
?>

This is [a very popular question](http://stackoverflow.com/search?q=cannot+modify+header+information+php) here `:-)`. — halfer, Nov 03 '13 at 12:52
One of your files it outputting something, possibly whitespace, before headers are sent. — Popnoodles, Nov 03 '13 at 12:53
Somewhere you have output before a cookie, session, or header call. It may just be an extra line break after `?>` or space before ` — Michael Berkowski, Nov 03 '13 at 12:53
@revo sessions aren't relevant to this problem. sesion.php may be setting headers, session already being started would produce a different error. — Popnoodles, Nov 03 '13 at 12:54

Artur · Answer 1 · 2013-11-03T13:03:56.040

2

I bet that in your session_begin() you have session_start(). Sessions are usually based on cookies which are 'header data'. If later in your code you use:

header(.....) // to set some additional header

and between session_start and invoking header you echo sth. - there will be issue since you cannot send header after sending data. You may also use session_start twice (and echo in between)

edited Nov 03 '13 at 13:03

answered Nov 03 '13 at 12:55

Artur

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I've moved my session start to the top of the code for this page and it seems to have fixed it – runelynx Nov 03 '13 at 13:05

PHP header warnings... why?

1 Answers1