PHP: double output of php errors / warnings / notices

Question

If I execute the following script:

<?php
error_reporting(E_ALL);
trigger_error('test notice', E_USER_NOTICE);
die('end of script');

I get the following output:

<br />
<b>Notice</b>:  test notice in <b>path/to/script/test.php</b> on line <b>3</b><br />
end of scriptPHP Notice:  test notice in path/to/script/test.php on line 3

The script was executed on IIS8 with PHP Version 5.4.19.

The http status code returned is 200.

"display_errors" is set to "On" and "error_reporting" to "E_ALL" in the php.ini file. So the first line of the script is just for clarification.

The behaviour is the same with all error reporting constants (E_ERROR, E_WARNING, etc.).

Does anyone know where the second output of the notice comes from? And especially how the get rid of it?

Answer 1

To solve this issue I had to change the base settings of the site in IIS: "Connect As" with the IIS_USER and the double output of php error messages were gone! I still don't know why, but at least it works.

Answer 2

If you set both

error_reporting(E_ALL);
ini_set('display_errors', 1);

The errors will be doubled:

PHP Notice: Undefined variable: test in /path/to/script.php on line 8

Notice: Undefined variable: test in /path/to/script.php on line 8

Try turning one or the other off or a set a custom error handler.

Answer 3

First line in your script

error_reporting(E_ALL);

Sets PHP to report all errors and with display_errors directive enabled in your PHP configuration which sets PHP to print errors to the screen, then no need to your second line which duplicates the output.