Since this gets asked alot, I figured I'd improvise a short hack guide to this.
Most Smaug bases require 4 things to add a new command:
1. The do_fun code for the command itself
2. A DECLARE_DO_FUN line in mud.h.
3. 2 entries in tables.c.
4. Use of the cedit command to activate it.
AFKMud does not require steps 2 and 3, but there is a difference in how step 1 needs to be done. For a command to work, it must be defined as a CMDF instead of a void.
void do_something( CHAR_DATA *ch, char *argument )
The above is what would work for Smaug. For AFKMud, use the following instead:
CMDF do_something( CHAR_DATA *ch, char *argument )
The main difference being the use of the CMDF macro. This was necessary in order to get g++ to accept the use of the dlsym code while also retaining compatibility with plain gcc for those who prefer that. The details aren't terribly important to know.
Step 4 of the process is the same:
cedit something create
cedit something create do_something
If you get an error that do_something is not found, then the source code is either missing or the code is using void instead of CMDF.
Any snippets which still use the void declarartion for do_something will need to be changed to CMDF format to make them work as well.