A short look at Permissions

 

1. Every object, property, an verb has a set of permissions
2. If you own an object, it does not necessarily mean that you own all the properties and all the verbs. To convince yourself, look at an object, e.g. type ' @d me.', this will list the properties of your character.

The table below gives a short and dirty overview on existing permissions:

 

Permission Objects Properties Verbs

r (read) ok ok ok

w (write) never almost never never

x (executable) - - use for ``this none this'' verbs

f (fertile) use for generics - -

d (debug) - - mostly

c (create) - sometimes in generic objects -

Let's point out the highlights first and look into ``f'' and ``c'' permissions in the next section.

• General:
  1. It is good custom to set read permissions on everything, because then people can look at your code, and decide whether it is safe to use it. ``r'' is default at TECFAMOO.
  2. Write permissions, means that EVERYBODY could:
     • add components to your object (object=w)
     • reprogram a verb (verb=w)
     • change the contents of properties (property=w).

     Only sometimes it can be useful to set a property to ``w'', i.e. if want people to set a slot representing information or so.

• Verbs
  1. ``x'' permissions are NEEDED for all verbs that are called by other verbs. If you create a ``this none this'' verb, x is added by default (but not if you change the argument specifiers of a verb with the '@arg' command! You can set command verbs to ``x'', if you wish to test them with the ';' (eval) or if you want to call them from other verbs.
  2. ``d'' permissions on verbs are recommended because if the verb breaks on an error it will print out ``feedback''.

Inspecting and Manipulating Permissions:

You can look at permissions by using the @display ('@d) command like in the following transcripts:

   >@d holder
   holder (#2108) [ readable fertile ]
     Child of generic thing (#5).
     Location island (#1429).
-------------------------------- finished -----------------------------

The object holder is readable and fertile

   >@d holder:show
    #2108:show      MooBoy (#1324)   r d    any on top of/on/onto/upon this
-------------------------------- finished -----------------------------

The :show verb is ``r'' and ``d'': readable and debug

>@d holder.holding
.holding         MooBoy (#1324)        r      {}
-------------------------------- finished -----------------------------

The ``.holding'' property is just readable. Now compare that to your holder. If you did not change anything since you worked last on your holding object, permissions should not be the same as above.

To change permissions, use the '@chmod' command (type 'help @chmod' in the MOO). E.g.

   @chmod holder +f

will make it fertile.

   @chmod holder +w
   @chmod holder -w

will make it writable (don't do that) first and then lock it for writing again.