lua何时触发查找，找的路径有哪些

require的时候

这里的require，需要查找person.lua文件

这个path的默认值：

static const char *searchpath (lua_State *L, const char *name,
                                             const char *path,
                                             const char *sep,
                                             const char *dirsep) {
    
    
  luaL_Buffer msg;  /* to build error message */
  luaL_buffinit(L, &msg);
  if (*sep != '\0')  /* non-empty separator? */
    name = luaL_gsub(L, name, sep, dirsep);  /* replace it by 'dirsep' */
  while ((path = pushnexttemplate(L, path)) != NULL) {
    
    
    const char *filename = luaL_gsub(L, lua_tostring(L, -1),
                                     LUA_PATH_MARK, name);
    lua_remove(L, -2);  /* remove path template */
    if (readable(filename))  /* does file exist and is readable? */
      return filename;  /* return that file name */
    lua_pushfstring(L, "\n\tno file '%s'", filename);
    lua_remove(L, -2);  /* remove file name */
    luaL_addvalue(&msg);  /* concatenate error msg. entry */
  }
  luaL_pushresult(&msg);  /* create error message */
  return NULL;  /* not found */
}