Function g_iofile

third-party/lua-5.5.0/src/liolib.c:320–334

static int g_iofile (lua_State *L, const char *f, const char *mode) {
  if (!lua_isnoneornil(L, 1)) {
    const char *filename = lua_tostring(L, 1);
    if (filename)
      opencheck(L, filename, mode);
    else {
      tofile(L);  /* check that it's a valid file handle */
      lua_pushvalue(L, 1);
    }
    lua_setfield(L, LUA_REGISTRYINDEX, f);
  }
  /* return current value */
  lua_getfield(L, LUA_REGISTRYINDEX, f);
  return 1;
}


static int io_input (lua_State *L) {