8.25.1. Problem

8.25.2. Solution

// get value
$session = apache_note('session');

// set value
apache_note('session', $session);

8.25.3. Discussion

When Apache processes a request from a client, it goes through a series of steps; PHP plays only one part in the entire chain. Apache also remaps URLs, authenticates users, logs requests, and more. While processing a request, each handler has access to a set of key/value pairs called the notes table. The apache_note( ) function provides access to the notes table to retrieve information set by handlers earlier on in the process and leave information for handlers later on.

// retrieve the session ID and add it to Apache's notes table
apache_note('session_id', session_id( ));

%{session_id}n

The trailing n tells Apache to use a variable stored in its notes table by another module.

If PHP is built with the --enable-memory-limit configuration option, it stores the peak memory usage of each request in a note called mod_php_memory_usage. Add the memory usage information to a LogFormat with:

%{mod_php_memory_usage}n

8.25.4. See Also