A Lua type that allows arbitrary C data to be stored in Lua variables. It's used to represent new types created by an application program or a library written in C.
Questions tagged [lua-userdata]
56 questions
2
votes
1 answer
How do user values in Lua C API and lua_newuserdatauv function in particular work?
The documentation for lua_newuserdatauv(lua_State *L, size_t size, int nuvalue) says
This function creates and pushes on the stack a new full userdata, with nuvalue associated Lua values, called user values, plus an associated block of raw memory…
Sun of A beach
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2
votes
0 answers
Lua life cycle of userdata and uservalue
I am creating userdata on Lua 5.3 and setting its uservalue (a table value). When I use collectgarbage() the uservalue is collected, however the userdata is not.
Why is the life cycle of userdata and uservalue different? How can I make the uservalue…
renyson
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2
votes
1 answer
Add a method to userdata
I am trying to add a method to an existing userdata like this, this however game me an error.
local userData = luajava.newInstance("Objects.Block") --creates a userdata from a Java class
userData.newMethod = function()
-- Do stuff
end
I…
Timotheus
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2
votes
1 answer
Convert Userdata to hex in Wireshark Dissector
I'm coding Wireshark Dissector lua script now.
How to convert userdata to hex string?
I want to get output like this 0102030405060708000a0b0c0d0e0f10
I can convert hex string using tostring.
But it omits long data.
Output Image
How to convert…
bugggy
- 156
- 2
- 10
2
votes
1 answer
Getting reference to userdata in a table using luaL_ref?
First of all, I appologize for not uploading the full code.
I'm trying to convert userdata to a pointer so it can be passed to other lua chunk using lua_rawgeti().
If you see outletRet() function, it checks the type of a returned value, and if it's…
Zack Lee
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2
votes
1 answer
How to index a converted userdata value?
I tried to convert C++ class to a void pointer using lua_touserdata() and then convert it back to C++ class using lua_pushlightuserdata().
However, I can't index variables in a class once I do the conversion.
Here's my test code:
MyBindings.h
class…
Zack Lee
- 2,784
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2
votes
1 answer
Lua userdata: Unable to have simultaneous array access and methods
I had this guy's problem:
Lua userdata array access and methods
wherein when I set the __index of my userdata's metatable, it always called the getter, instead of my other methods that weren't declared for meta-events. The solution to the above link…
Lars
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2
votes
1 answer
Storing and Returning Lua Userdata
I have the following classes in C++
class B;
class A {
B* GetB();
void SetB(B*& b) { _b = b;};
private:
B* _b;
}
And part of the lua binding code:
int A::setB(lua_State* L) {
A* a = checkA(L,1) // Macro for luaL_checkudata
B*…
Moop
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2
votes
2 answers
Lua userdata gc
Is it possible for a piece of Lua userdata to hold reference to a Lua object? (Like a table, or another piece of userdata?). Basically, what I want to know is:
Can I create a piece of userdata in such a way taht when the gc runs, the user data can…
anon
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2
votes
2 answers
./lua/addtest.lua:9: attempt to index local 'testobj' (a userdata value)]]
test.exe call addTest.lua and set the lua_testobj to the table, and addTest.lua call testobj.dll,
but testobj.dll can not get the "lua_testobj"
error msg is
addTest.lua:9 attempt to index local 'testobj' (a userdata value)
test.exe
L =…
Sleepwom
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2
votes
1 answer
Lua API push userdata
I'm trying to give a scripting ability to my component system. Of couse each component has a field "parent" which holds access to the parent Actor. I can write the code so I can access my C++ methods from Lua, but I got stuck when I want to return…
RobeeZ
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2
votes
0 answers
Lua light userdata
I have a problem with Lua and I don't know if I going in the right direction. In C++ I have a dictionary that I use to pass parameter to a resource manager. This dictionary is really similar to a map of hash and string.
In Lua I want to access to…
ilmale
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2
votes
2 answers
How to add a reference to table to userdata object?
I have a function in lua that accepts a userdata object.
function Class:AttachToUserdataObject(userdataObject)
userDataObject.tableAttached = self
end
But later on, when I am using the same userdata object, I can't find it -…
Nebril
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2
votes
2 answers
Lua RPC and userdata
I'm currently using luarpc in my program to make interprocess communication. The problem now is that due to my tolua++ binding which stores class instances as userdata im unable to use any of those functions cause luarpc cant handle userdata. My…
ACB
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1
vote
3 answers
Wireshark dissector in Lua - userdata
I am new to Lua, and I am building a custom dissector for Wireshark. My situation is this:
The wireshark data consists of hex numbers such as 4321 8765 CBA9. What I would like to wind up with is (after it has been dissected) : CBA9 8765 4321.
What…
user1006262
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