header sent problem

nogeekyet

I have read in the manual why I have this problem, but I can't figure out how to circumvent it. For testing, my code looks like this:
<html>
<head>
<title>General Login</title>
</head>
<body oncontextmenu="return false;">
<?php
require_once('includes/GetTstCookie.inc');
?>
<center>

The code for the GetTstCookie.inc couldn't be any simpler:
<?php
if (!isset($_COOKIE['tst_cookie'])){
header("Location: error.php"); }
?>
However, I get the error on the header line.

leatherback

If you have read the manual, you also have read that you cannot output anything to the browser before header() commands. THat means absolutely nothing. Also not <html> or spaces.

sh0wtym3

Is there any way to force the php code to allow html before the header() commands?

I have a similar problem but I need the html to come first.

I edited my php.ini file to reflect "output_buffering = On", but it didn't help.

leatherback

using output buffering is one option. The other (Which I prefer, as i use templates for my output anyway) is storing your output in a variable yourself.

Cant help you with output buffering as I do not use it, but I think you need to take a few steps in your code for it to actually buffer. Read up in the manual

bradgrafelman

sh0wtym3 wrote:
I have a similar problem but I need the html to come first.

Why? Why can't you simply execute the PHP code that might need to modify headers before you output HTML?

Output buffering has never been a "solution" to this problem in my mind, only a workaround (one that sacrifices the server's memory to allow for less-refined code).

sh0wtym3

leatherback wrote:
using output buffering is one option. The other (Which I prefer, as i use templates for my output anyway) is storing your output in a variable yourself.

Cant help you with output buffering as I do not use it, but I think you need to take a few steps in your code for it to actually buffer. Read up in the manual

Thanks for pointing me in the right direction, I did need to take one more step.

Solution: Adding ob_start(); at the beginning of my php code, and ob_end_clean(); at the end of it.

Now it works perfectly fine. With html before the header() function!

sh0wtym3

bradgrafelman wrote:
Why? Why can't you simply execute the PHP code that might need to modify headers before you output HTML?

Output buffering has never been a "solution" to this problem in my mind, only a workaround (one that sacrifices the server's memory to allow for less-refined code).

Because there is output (such as echo statements) that I need to appear below the html code. But I figured out a way around it using output buffering.

Is it that taxing on a server's memory though?

bradgrafelman

sh0wtym3 wrote:
Is it that taxing on a server's memory though?

There's really no definite yes or no there. If the content that is to be buffered is small and there aren't many concurrent hits, and assuming your server doesn't have a small amount of RAM, then most likely not.

I've just always been against this method of "fixing" the headers problem. It's always seemed like a duct-tape-solution to me. In your situation, for example, why can't you separate the echo statements from the header()/setcookie()/etc. functions? HTTP headers are already sent before any of the HTML, so it should be natural that they should precede any data in PHP scripts.