Adding Commands to an EmberMUD (v1.0)
                       (For EmberMUD .029 and .029b)
                                by Ron Cole


(Some snippets borrowed from the EmberMUD codebase, which is based on 
ROM 2.3, which is based on MERC, which is based on DIKU. )


Step #1: Plan the command.
        The first step in command creation is to plan out exactly 
 what command you wish to add.  Here are some questions you might 
 want to have answered before going any further:
 

   What will this command do?  
   
   Is there another command that already does this?

   Will this command be used in combat?

   What skills will help in the execution of this command?

   What stats will help in the execution of this command?

   What level should one have to be before they can use this 
   command?  Every?  High level?

   Can this command be done in every room type, or just one?

   Do I have to have a special object in order to execute 
   my command?

   What races can use this command?  

   Are any special body parts needed to execute this command?


Step 2: Write and add the function the command will execute.
        This is the most important part of the command, yet also 
 the part which this document gives the least help on.  You must 
 decide WHAT your command does, and then code it as a function. 
 For help on the programming part, look at other functions in the
 code and buy a really good C programming book.  Once you have 
 written your function, simply place it into the most appropriate
 *.c file.  It is not necessary to declare the function in the 
 header of most *.c files.  Note that most functions start with 
 a do_ if the have the same name as the command.  For instance,
 the command NORTH calls the function do_north.


Step 3: Add the appropriate line of code in interp.c.
        You must add the appropriate line of code to the command 
 table in interp.c.  Here is an example of the command table:

    { "name",   function,   position,     trust,    logging,    show },
 

 What it means...
    
    name: What someone will type in to execute the command.

    function: The name of the function that will be called.  It
    should probably start with a do_.

    position: What position (SLEEPING, STANDING, etc..) the character
    must be in or beyond in order to execute the command.

    trust: The trust level someone must have in order to execute the
    command.  If you want to have IMM only commands, this is where
    you do it.

    Logging: Does this command get logged when you execute it? 


        Now, plug the values that you want into the structure, and 
    then add it to the table.  For help with what positions and log
    options you have, see the appendix at the end of this document.
    Below are two examples of commands within the command table:

    
    { "north",          do_north,       POS_STANDING,    0,  LOG_NEVER, 0 },
    { "east",           do_east,        POS_STANDING,    0,  LOG_NEVER, 0 },


Step 4: Add the appropriate line of code in interp.h.
        Find the declarations in interp.h, and add the name of your 
 function to it.  Here are two examples:

DECLARE_DO_FUN( do_advance      );
DECLARE_DO_FUN( do_afk          );


Step 5: Adding help files.
        You will need to add a help file for your command, as well 
 as altering any other appropriate help files ( if you added a new  
 channel, for instance, you would also need to modify the gossip 
 help).  These files can be found in help.are within the area directory.


- Appendixes -  (Most of which can be found in interp.h)

  
  Log List:  
        LOG_NORMAL      Only logs when someone is being logged.
        LOG_ALWAYS      Logs who executed the function every time.
        LOG_NEVER       The function is not logged.
  

Position List:
        POS_DEAD                      0
        POS_MORTAL                    1
        POS_INCAP                     2
        POS_STUNNED                   3
        POS_SLEEPING                  4
        POS_RESTING                   5
        POS_SITTING                   6
        POS_FIGHTING                  7
        POS_STANDING                  8


  Trust List:
        ML      MAX_LEVEL       /* implementor */
        L1      MAX_LEVEL - 1   /* creator */
        L2      MAX_LEVEL - 2   /* supreme being */
        L3      MAX_LEVEL - 3   /* deity */
        L4      MAX_LEVEL - 4   /* god */
        L5      MAX_LEVEL - 5   /* immortal */
        L6      MAX_LEVEL - 6   /* demigod */
        L7      MAX_LEVEL - 7   /* angel */
        L8      MAX_LEVEL - 8   /* avatar */
        IM      LEVEL_IMMORTAL  /* angel */
        HE      LEVEL_HERO      /* hero */
        0       Anyone can use the command.


 Did I miss anything?  If so, feel free to e-mail me with your comments
 and suggestions at clogar@concentric.net.

                                  - END -