SoFunction
Updated on 2025-03-02

Lua programming example (VI): Calling Lua functions in C language

C++ side:

#include ""

lua_State *L;
void load_lua(lua_State **L,char *filename){
 *L=luaL_newstate();
 luaL_openlibs(*L);
 if(luaL_loadfile(*L,filename) || lua_pcall(*L,0,0,0)){
 luaL_error(*L,"load file error! %s",lua_tostring(*L,-1));
 }
}
int _tmain(int argc, _TCHAR* argv[])
{
 load_lua(&L,""); //If you pass it directly into L here, you will have an error lua_getglobal(L,"gettable");
 if(lua_pcall(L,0,1,0) !=0){
 luaL_error(L,"pcall wrong %s",lua_tostring(L,-1));
 }
 luaL_checktype(L,1,LUA_TTABLE);
 int n=lua_objlen(L,1);
 printf("n = %d\n",n);
 lua_pushstring(L,"ee");
 lua_rawseti(L,1,5); //t[n]=v,n is the third parameter, v is the top element of the stack n=lua_objlen(L,1);
 printf("n = %d\n",n);
 int i;
 for(i=1;i<=n;i++){
 lua_rawgeti(L,1,i);
 printf("%s\n",lua_tostring(L,-1));
 }
 return 0;
}

lua script:

 

function gettable() 
  tb={ "aa","bb","cc","dd"} 
  return tb 
end 

The result of running the output is:

n = 4 
n = 5 
aa 
bb 
cc 
dd 
ee