PHP标头未发送到浏览器

Question

I have quite a strange problem with PHP and Apache on my local testing server. For some reason it keeps stopping sending headers to the browser (I am pretty sure that is the problem anyway).

It's not a case of the old 'output already sent' as it was working fine, had the problem, went away after I reinstalled Apache and is now back again. Sessions also appear to be broken. It also gives no errors for 'headers already sent', plus the code works on the live site.

It's not the browser either as I tried different browsers and different machines, which exhibit the same problems.

Even something dumb such as <?php header ('Location: http://www.yahoo.com'); ?> <?php header ('Location: http://www.yahoo.com'); ?> doesn't work.

I am running wampserver (latest version) on Windows. Answers on a postcard.

Answer 1

Even something dumb such as <?php header ('Location: http://www.yahoo.com'); ?> <?php header ('Location: http://www.yahoo.com'); ?> doesn't work.

Try with this instead:

<?php header('Location: http://www.yahoo.com'); exit; ?>

Answer 2

Firstly, check that your PHP.INI has 'display_errors' set to 'On' and while you're at it, make sure 'error_reporting' is set to 'E_ALL & ~E_NOTICE'. Without those, you won't see errors even if they occur.

Secondly, ensure that you set 'output_buffering' to 'Off' in the same file. Just in case.

Finally, there was mention of checking your Apache log. It's also important to check your PHP error log (which is generally a different file again).

Answer 3

重新安装修复它，非常奇怪。

Answer 4

If you were using Xdebug on February 2010, it used to have a known issue with generated HTTP headers:

• 0000532: XDebug breaks header() function

This issue is now fixed so either switch to a newer version or remove the extension altogether.