Add more getter functions/methods for the Lua API

[Wuzzy2]

The Lua API has a lot of setter functions/methods (for setting a value) but it lacks many corresponding getter functions (for receiving a value). I suggest to add these getter functions.

I personally think there is in most cases no reason not to have such functions. It is just inconsistent and incomplete.

The suggested function/method names are like the setter functions, but with “get” instead of “set”. There is a single exception. After the arrow, I write the suggested return value. It is just the same as the input parameters. Remember that Lua functions can return multiple values at once, for example: return 1,2,3,4. I wrote the functions which I consider the most important in bold type.

So, here I list the functions I think are lacking in the Lua API:

For ObjectRefs:

• get_properties → object_property_table
• get_armor_groups → table_of_group_ratings (I tested it with the luacmd mod this function does not exist for players; since players are basically ObjectRefs, I conclude that this is true for other ObjectRefs as well)
• get_animation → group_rating_table, frame_speed, frame_blend
• get_attach → parent, bone, position, rotation
• get_bone_position → bone, position, rotation

For player objects:

• get_physics_override → the same table used as input for set_physics_override
• hud_get_hotbar_itemcount → number
• hud_get_hotbar_image → texture path
• hud_get_hotbar_selected_image → texture path
• get_sky → bgcolor, type, {texture names}
• get_day_night_ratio (getter function for to override_day_night_ratio) → ratio or nil
• get_local_animation → see input parameters of set_local_animation
• get_eye_offset → first_person_offset, third_person_offset

Global functions:

• minetest.get_gen_notify → flags (a string)
• minetest.get_player_password (OK, let’s just forget this suggestion, shall we?)
• minetest.get_mapgen_params → MapgenParams
• minetest.get_noiseparam_defaults → see minetest.set_noiseparam_defaults

For all suggested function names, I checked lua_api.txt if it already exists. It did not.

If you think I missed a function, please write a comment.

[sfan5]

minetest.get_player_password → I don’t know, need to think about this.

It would be a major security concern if adding this functionality would even be possible.

[Wuzzy2]

OK, then let’s throw this part of the suggestion out of the window then. The rest of the suggestion still stands, of course.

[ShadowNinja]

Minetest stores passwords hashed and (mildly) salted, so getting the original password should be impossible without brute-forcing it. However, you can easily get the password hash from minetest.auth_table[player_name].password, or, of course, by opening and reading auth.txt.

[sfan5]

[...], so getting the original password should be impossible without brute-forcing.

getting the original password is impossible without brute-forcing!

[webD97]

Security problems! honestly? modders have unlimited access to the io functions, that's the problem.
A getter function for a player's password can be useful sometimes, e.g. "pls confirm this action with your password". An alternative would be something like compare_with_playerpassword("string") -> true|false

[sfan5]

compare_with_playerpassword("string") -> true|false

that's easy

function minetest.compare_player_password(name, password)
    return minetest.get_password_hash(name, password) == minetest.auth_table[name].password
end

[webD97]

Cool. It should be in builtin :)

[nerzhul]

@ShadowNinja because you are working on mod_security can you provide us some advices on this issue ?

[ShadowNinja]

@nerzhul: This doesn't interact with mod security.

[TeTpaAka]

This can get closed now. c0335f7

[Wuzzy2]

Thank you very much! Finally it is in. :-)