const char *name = luaL_checkfilename(lua_State *L, int numArg);
luaL_checkfilename() checks
if there is a filename at the given stack index. When working with files, you
should always use this function instead of luaL_checklstring() because luaL_checkfilename()
is able to work with linked files as well. For example, if the user passes the
filename menulogo.png to your function and this file does not physically
exist, but has been linked to your applet or executable using Hollywood's
‘-linkfiles’ option, luaL_checkfilename() will automatically set up a
special virtual file name specification that is understood by hw_FOpen()
and hw_TranslateFileName() and return it to you.
luaL_checklstring(), however, would just return the string menulogo.png to you,
leading to a failure as soon as you try to open this non-existent file.
Please note that like all other luaL_checkxxx() functions, this function will
immediately jump into Hollywood's error handler if an error occurs. It will
never return NULL. If luaL_checkfilename() returns, then it has been successful
as well. If there is an error, luaL_checkfilename() won't return control to you
at all.
lua_State