How do I check if file name is a directory or not in C?

Question

我正在使用if(strstr(dir->d_name, ".") == NULL && strstr(dir->d_name, "..")来检查它是否是一个目录/子目录，但这仍然是打印出一些文件这不是目录...我使用直接结构和DIR。

Answer 1

strstr searches for a substring inside another string, so it will return a match for every name that contains a single (well, or a double) period.

You probably meant to use strcmp :

if (strcmp(dir->d_name, ".") && strcmp(dir->d_name, ".."))
   .. not one of the default root folders ..

Before or after this, you can check if it is a folder or not:

if (dir->d_type == DT_DIR)
  ..

or use stat . (Note that d_type may not be supported by certain file system types.)

Answer 2

Personally, I like stat() and fstat(). You then look at the st_mode field of the output with macros like S_ISDIR(m).

Answer 3

If you're on Linux, you can use getdents which include entry type. Otherwise you'll probably have to use stat / lstat to get type info for every item.