RE: luaL_dofile(): how do I get errors?

["Jerome Vuarand" <jerome.vuarand@...>]

Shea Martin wrote:
> If my embedded interpreter encounters an error in the script, 
> during the
> dofile() routine, it just punts.  dofile return a value of 1, 
> so I know an error was encountered, but I have no idea what 
> the error was.  There is no error message printed, etc.
> 
> Is there any sort of way to determine what is wrong with my 
> script, and print a message to the user?
> 
> I don't think lua_pcall() is what I want, as it calls a 
> function.  I am still loading the script.

As you can see in its doc luaL_dofile is defined as:

    luaL_loadfile(L, filename) || lua_pcall(L, 0, LUA_MULTRET, 0))

It is then equivalent to a lua_pcall if loadfile suceeds. As you can see
in the documentation of luaL_loadfile and lua_pcall, if there is an
error on any of these functions it is left on top of the stack as a
string. To simply print it do the following:

int somefunction(lua_State* L)
{
    if (luaL_dofile(L, "myscript.lua"))
    {
        printf("%s\n", lua_tostring(L, -1));
    }
    return 0;
}