Apache – How to List Enabled Modules

There is no equivalent.

Debian/Ubuntu butcher the apache configuration into a large number of files, where directories of mods and sites enabled are symlinked to other snippets of configuration files. The a2enmod/a2ensite scripts just manipulate these symlinks.

debian$ ls /etc/apache2/mods-enabled 
lrwxrwxrwx 1 root root 28 2009-03-12 18:02 alias.conf -> ../mods-available/alias.conf
lrwxrwxrwx 1 root root 28 2009-03-12 18:02 alias.load -> ../mods-available/alias.load
lrwxrwxrwx 1 root root 33 2009-03-12 18:02 auth_basic.load -> ../mods-available/auth_basic.load
lrwxrwxrwx 1 root root 33 2009-03-12 18:02 authn_file.load -> ../mods-available/authn_file.load
lrwxrwxrwx 1 root root 36 2009-03-12 18:02 authz_default.load -> ../mods-available/autoindex.load
lrwxrwxrwx 1 root root 26 2009-03-12 18:02 env.load -> ../mods-available/env.load
lrwxrwxrwx 1 root root 27 2009-03-12 18:02 mime.conf -> ../mods-available/mime.conf
lrwxrwxrwx 1 root root 27 2009-03-12 18:02 mime.load -> ../mods-available/mime.load
lrwxrwxrwx 1 root root 34 2009-03-12 18:02 negotiation.conf -> ../mods-available/negotiation.conf
lrwxrwxrwx 1 root root 34 2009-03-12 18:02 negotiation.load -> ../mods-available/negotiation.load
lrwxrwxrwx 1 root root 27 2009-06-16 21:47 php5.conf -> ../mods-available/php5.conf
lrwxrwxrwx 1 root root 27 2009-06-16 21:47 php5.load -> ../mods-available/php5.load

On redhat systems the apache configuration is by default held in one file /etc/httpd/conf/httpd.conf. All modules are loaded from this file, and can be disabled by commenting out the appropiate LoadModule statement.

...
LoadModule authz_default_module modules/mod_authz_default.so
LoadModule ldap_module modules/mod_ldap.so
LoadModule authnz_ldap_module modules/mod_authnz_ldap.so
LoadModule include_module modules/mod_include.so
LoadModule log_config_module modules/mod_log_config.so
LoadModule logio_module modules/mod_logio.so
LoadModule env_module modules/mod_env.so
LoadModule mime_module modules/mod_mime.so
LoadModule dav_module modules/mod_dav.so
...

What RedHat/CentOS are doing is giving you a pretty stock apache setup, while debian are adding their own "improvements". You could of course use the debian split config system as a template to make your own, and copy the scripts. However, the main argument for the debian setup is so that apache module packages can install their own config files, so without that it's significantly less useful

Edit: If you're looking for an equivalent way of scripting this then i suggest you use /etc/httpd/conf.d directory, any config files in here will be included. Depending on how complicated the script is it might make sense to directly write one line files into conf.d, or use symlinks for more complicated bits.

As of GNU coreutils 7.5 released in August 2009, sort allows a -h parameter, which allows numeric suffixes of the kind produced by du -h:

du -hs * | sort -h

If you are using a sort that does not support -h, you can install GNU Coreutils. E.g. on an older Mac OS X:

brew install coreutils
du -hs * | gsort -h

From sort manual:

-h, --human-numeric-sort compare human readable numbers (e.g., 2K 1G)