Tom Leese Tom Leese - 10 months ago 98
C Question

Pushing a Lua table

I have created a Lua table in C, but I'm not sure how to push that table onto the top of a stack so I can pass it to a Lua function.

Does anyone know how to do this?

This is my current code:

lua_createtable(state, libraries.size(), 0);
int table_index = lua_gettop(state);
for (int i = 0; i < libraries.size(); i++)
lua_pushstring(state, libraries[i].c_str());
lua_rawseti(state, table_index, i + 1);

lua_settable(state, -3);

[ Push other things ]
[ Call function ]

Answer Source

Here's a quick helper function to push strings to the table

void l_pushtablestring(lua_State* L , char* key , char* value) {
    lua_pushstring(L, key);
    lua_pushstring(L, value);
    lua_settable(L, -3);

Here I use the helper function to create the table and pass it to a function

// create a lua function
luaL_loadstring(L, "function fullName(t) print(t.fname,t.lname) end");
lua_pcall(L, 0, 0, 0);

// push the function to the stack
lua_getglobal(L, "fullName");

// create a table in c (it will be at the top of the stack)
l_pushtablestring(L, "fname", "john");
l_pushtablestring(L, "lname", "stewart");

// call the function with one argument
lua_pcall(L, 1, 0, 0);