It doesn't look like the apache binary itself will provide this info - from apache docs:
-S
Show the settings as parsed from the config file (currently only shows
the virtualhost settings).
There exist options to show modules loaded and compile-time flags used, but the above is the only option related to config settings. It seems even the CGI environment available, as well as info returned by mod_status does not contain the type of details you're looking for.
However, all is not lost - if you're prepared to enable/install the apache module mod_info, you'll find it answers that and many more questions regarding apache configuration.
Example output from the "Server Settings" page of the localhost/server-info location:
Server Version: Apache/2.2.9 (Debian)
PHP/5.2.6-1+lenny4 with Suhosin-Patch
mod_ssl/2.2.9 OpenSSL/0.9.8g
mod_wsgi/2.5
Python/2.5.2
Server Built: Nov 14 2009 20:23:49
Module Magic Number: 20051115:15
Hostname/port: localhost:80
Timeouts: connection: 300
keep-alive: 300 MPM Name: Prefork
MPM Information: Max Daemons: 150
Threaded: no Forked: yes Server
Architecture: 32-bit Server Root:
/etc/apache2 Config File:
/etc/apache2/apache2.conf
Note the keep-alive highlighted - if your intention is to script the check (although this could also be done against the config file itself), I think calling lynx --dump localhost/server-info
could well assist in your endeavour (after a quick call to a2enmod info
and an apache restart).
HTH, and YMMV. :)