c - dirent.h 将所有文件读取为 DT_UNKOWN

Question

这个问题已经有答案了:

Checking if a dir. entry returned by readdir is a directory, link or file. dent->d_type isn't showing the type (4 个回答)

已关闭 3 年前。

我正在使用dirent.h递归读取目录中的文件。在我的Debian GNU/Linux 7 (wheezy)上它工作正常，但是在Ubuntu 12.04 LTS上服务器将所有文件读取为 DT_UNKOWN!

if ((dir = opendir (input_dir)) != NULL)
{
  while ((ent = readdir (dir)) != NULL)
    {
       // cat dir path to file
      char full_file_path[FILE_NAME_LENGTH];
      strcpy (full_file_path, input_dir);
      strcat (full_file_path, "/");
      strcat (full_file_path, ent->d_name);
      // if "." or "..", skip it
      if (!strcmp (ent->d_name, ".") || !strcmp (ent->d_name, ".."));
        // if a regular file, process it
      else if (ent->d_type == DT_REG)
        {
          process_file (full_file_path, f_out, z, ws);
        }
        // if a directory, recurse through it
      else if (ent->d_type == DT_DIR)
        {
          // add '/' to the end of the directory path
          process_directory (full_file_path, f_out, z, ws);
        }
      else
        {
          printf ("%s is neither a regular file nor a directory!\n",
                  full_file_path);
        }
    }
}

Answer 1

根据手册页(man 3 readdir):(虽然这是来自 Fedora，但我想 Ubuntu 不会有太大不同)

Currently, only some filesystems (among them: Btrfs, ext2, ext3, and ext4) have full support for returning the file type in d_type. All applications must properly handle a return of DT_UNKNOWN.

不保证可以从d_type读取文件类型。您应该转而使用 stat 来获取所需的信息。