findex            196 lib/lua/liolib.c static FILE *getiofile (lua_State *L, int findex) {
findex            198 lib/lua/liolib.c   lua_rawgeti(L, LUA_ENVIRONINDEX, findex);
findex            201 lib/lua/liolib.c     luaL_error(L, "standard %s file is closed", fnames[findex - 1]);