Re: Please help me

[Bradley Smith <gmane@...>]

Abhinav Lele wrote:
> I am trying to run a function from C code, but I am unable to do so.
>
> Code:
> #include <stdio.h>
> #include "lua/lua.h"
> #include "lua/lualib.h"
> #include "lua/lauxlib.h"
>
> int main() {
>     lua_State * lc;
>     lc = lua_open();
>     if(lc == NULL) return 1;
>     luaopen_base(lc);
>     luaopen_table(lc);            /* opens the table library */
>     luaopen_io(lc);               /* opens the I/O library */
>     luaopen_string(lc);           /* opens the string lib. */
>     luaopen_math(lc);             /* opens the math lib. */
>     char *lua_script = "function f(x,y)\n return 145\n end";
>     if(luaL_loadbuffer(lc, lua_script, strlen(lua_script), "line") != 0) 
> { printf("ERRLoad\n"); return 3; }

      /*
       * luaL_loadbuffer pushes the compiled script as a
       * Lua function on top of the stack. The function
       * must be executed to have any effect on the Lua state.
       */
      if (lua_pcall(lc, 0, 0, 0) != 0) {
        printf("error running script: %s\n",
               lua_tostring(lc, -1));
        return 1;
      }


>     double x,y,z;
>
>           /* push functions and arguments */
>           lua_getglobal(lc, "f");  /* function to be called */
>           lua_pushnumber(lc, x);   /* push 1st argument */
>           lua_pushnumber(lc, y);   /* push 2nd argument */
>
>           /* do the call (2 arguments, 1 result) */
>           if (lua_pcall(lc, 2, 1, 0) != 0)
>             printf("error running function `f': %s",
>                      lua_tostring(lc, -1));
>
>           /* retrieve result */
>           if (!lua_isnumber(lc, -1))
>             printf("function `f' must return a number");
>           z = lua_tonumber(lc, -1);
>       lua_pop(lc, 1);  /* pop returned value */
>     lua_close(lc);
>     return 0;
> }
>
> Error:
> error running function `f': attempt to call a nil valuefunction `f' must 
> return a number