Re: luaL_loadfilex returns LUA_ERRSYNTAX when file has wrong mode

[Roberto Ierusalimschy <roberto@...>]

> > > The documentation for luaL_loadfilex specifies that it'll return
> > > LUA_ERRFILE when the file has the wrong mode:
> > >
> > >     "This function returns the same results as lua_load, but it has an
> > >     extra error code LUA_ERRFILE if it cannot open/read the file or the
> > >     file has a wrong mode."
> > >
> > > Sadly, this does not seem to be the case as the error code
> > > LUA_ERRSYNTAX is returned instead.
> > >
> > > Here we attempt to load the empty file 'test.lua' in binary mode:
> > >
> > >     int status = luaL_loadfilex(L, "test.lua", "b");
> > >
> > > Since 'test.lua' is not a valid Lua bytecode binary file, I would've
> > > expected the status code to be LUA_ERRFILE as documented. Is this a
> > > documentation error by any chance?
> > >
> > > I've attached a sample program that demonstrates this behaviour.
> > >
> > > Thanks!
> > 
> > I think the 'mode' referred to is the actual 'mode' of the file on the
> > disk (like what is returned by `stat`).
> > e.g. if you call luaL_loadfilex on a directory, it will return LUA_ERRFILE
> 
> That is correct. As the "FILE" in "LUA_ERRFILE" hints, this code is used
> only for file-related problems. We will try to make that clearer in the
> manual.

(BTW, note that only 'luaL_loadfilex' can return this code; 'lua_load'
does not use it.)

-- Roberto