How do I solve the Headers already sent warning problem?

Techissue2008

I have a index.php page need to include a login.php page as many php pages needs to use the same login interface and code.

Here is the code:

<?php
session_start();
?>
<html>
<head>
<title>test</title>
<META http-equiv=Content-Type content="text/html; charset=utf8">
<META NAME="description" CONTENT="test">
<META NAME="keywords" CONTENT="test">
<link href="style.css" rel="stylesheet" type="text/css">
<script language="JavaScript" src="g.js"></script>
</head>
<body>
<table width="100"><?php ob_start(); include 'login.php'; ob_end_flush();?><tr>

Here is the warning message:
Cannot modify header information - headers already sent by (output started at /home/www/index.php:11) in /home/www/login.php on line 16

I read:
http://codex.wordpress.org/FAQ_Troubleshooting#How_do_I_solve_the_Headers_already_sent_warning_problem.3F

http://www.webmasterworld.com/php/3519848.htm

http://us2.php.net/ob-start

I tried all methods. After I login, that error message would be shown.

However, I cannot place the login.php's code on the top of all php pages (before <html> tage) which need it.

How should I fix it now?

Thanks for any advice.

cahva

Paste us some code from login.php (at least to line 16-17). The problem is quite simple really, dont output anything before using header function. You probably have some checks if person is logged in and if he/she is not, then redirect him/her to some other page? You have to move this logic to the beginning of the page(separate code from presentation). Other way is this but I do not prefer this way:

<?php
session_start();

ob_start();
include 'login.php';
$login = ob_get_clean();
?>
<html>
<head>
<title>test</title>
<META http-equiv=Content-Type content="text/html; charset=utf8">
<META NAME="description" CONTENT="test">
<META NAME="keywords" CONTENT="test">
<link href="style.css" rel="stylesheet" type="text/css">
<script language="JavaScript" src="g.js"></script>
</head>
<body>
<table width="100"><?php echo $login; ?><tr>

Techissue2008

Thanks for your sound advice. I fixed it by the followings:

<?php 
session_start(); 
ob_start(); 
?> 
<table width="100"><?php include 'login.php'; ob_end_flush();?><tr>

bradgrafelman

Just as a note... using ob_start() isn't exactly "fixing" this type of problem, it's more of a workaround that sacrifices some memory. The true "fix" would be to execute the code that might possibly lead to a header() call before any HTML code is outputted.

Either way, don't forget to mark this thread resolved.