http headers - How to send 500 Internal Server Error error from a PHP script

Question

I need to send "500 Internal Server Error" from an PHP script under certain conditions. The script is supposed to be called by a third party app. The script contains a couple of die("this happend") statements for which I need to send the 500 Internal Server Error response code instead of the usual 200 OK. The third party script will re-send the request under certain conditions which include not receiving the 200 OK response code.

Second part of the question: I need to setup my script like this:

<?php
    custom_header( "500 Internal Server Error" );

    if ( that_happened ) {
        die( "that happened" )
    }

    if ( something_else_happened ) {
        die( "something else happened" )
    }

    update_database( );

    // the script can also fail on the above line
    // e.g. a mysql error occurred

    remove_header( "500" );
?>

I need to send 200 header only after the last line has been executed.

Edit

A side question: can I send strange 500 headers such as these:

HTTP/1.1 500 No Record Found
HTTP/1.1 500 Script Generated Error (E_RECORD_NOT_FOUND)
HTTP/1.1 500 Conditions Failed on Line 23

Will such errors get logged by the webserver?

Answer 1

header($_SERVER['SERVER_PROTOCOL'] . ' 500 Internal Server Error', true, 500);