What does this mean?

jonno946

Warning: Cannot send session cache limiter - headers already sent (output started at http://www.00000.com/header.php:8) in /usr/local/psa/home/vhosts/000000.com/httpdocs/forums/buddy/buddies_ignores.php on line 30

what does this mean and how do i prevent it? i think it mite be becouse i am inclluding two files that both use the same session. what sjhould i do? I have the following files included into one page;

page.php
- header.php (dynamic - Mysql and sessions)
- buddies_ignores.php(dynamic - Mysql, sessions
-footer.php - plain html

Thanx

van__

it means you tried sending a header after you had sent page output (body content)
Do not do this 🙂

just move the session start to someplace before your first echo or print statement
or put these funct calls on your page:

<?
//put this at the very top...
ob_start();

// all your code here //

//and at the very bottom:
ob_end_flush();
?>

Output buffering in PHP-4.x.x allows for headers to be written during the duration of the script untill the first flush.

[deleted]

To elaborate, the session headers (or any other headers for that matter) must be the first thing that is output.

This means you may not output/print anything. That includes HTML outside the <? ?> tags!

this will fail:

<?
session_start();
?>
<body>

A common mistake is that people have an empty line at the top of the file, just before the opening PHP tag. Searching for that can keep you busy a few hours 🙂

A forum, a FAQ, email notification, what else do you need?

Time to YAPF!: http://www.hvt-automation.nl/yapf/

jonno946

so at the top of header.php i put;

ob_start();

... and at the bottom of footer.php i put

ob_end_flush();

????

[deleted]

Something like that.

Except, you never ever start and stop output buffering in included/prepended/appended scripts.

Why not? because output buffering will keep all the data in a buffer untill you call ob_end_flush(). If you don't use ob_end_flush(), you don't get output.

Instead, use ob_start(), then include the header.php, then process the page, then include the footer.php, and then call ob_end_flush().

A forum, a FAQ, email notification, what else do you need?

Time to YAPF!: http://www.hvt-automation.nl/yapf/

van__

also, it's probably not a good idea to use exit or die with output buffering.

I see way too much
mysql_connect() or die("stupid message here");
going on around on this here board, and since that will terminate the script right then and there, I would remove that kind of stuff from your scripts.

[deleted]

That is a very good point (one that I regularly make myself🙂 )

Instead of 'or die', set a var to reflect the fact that an error occured.
Then at the end of your script, you can check to see wether any errors occured, and if there were errors, you can trash the output that was generated up to now, and replace it with a clean error message;

if (!mysql_query())
{
$bAnErrorOccured = TRUE;
$aErrorMessages[] = 'Query error'.mysql-error();
}
else
{
// Process data
}

// end of script, check for errors
if ($bAnErrorOccured == true)
{
// Errors have occured, print the messages
ob_end_clean();
echo '<pre>';
print_r($aErrorMessages);
echo '</pre>';
}
else
{
// No errors, print the page.
ob_end_flush();
}