tests/d_type-check

   1 #!/usr/bin/python
   2 # Exit 0 if "." and "./tempfile" have useful d_type information, else 1.
   3 # Intended to exit 0 only on Linux/GNU systems.
   4 import os
   5 import sys
   6 import tempfile
   7
   8 fail = 1
   9 fname = None
  10
  11 try:
  12   import ctypes.util
  13
  14   (DT_UNKNOWN, DT_DIR, DT_REG) = (0, 4, 8)
  15
  16   class dirent(ctypes.Structure):
  17     _fields_ = [
  18       ("d_ino", ctypes.c_long),
  19       ("d_off", ctypes.c_long),
  20       ("d_reclen", ctypes.c_ushort),
  21       ("d_type", ctypes.c_ubyte),
  22       ("d_name", ctypes.c_char*256)]
  23
  24   # Pass NULL to dlopen, assuming the python
  25   # interpreter is linked with the C runtime
  26   libc = ctypes.CDLL(None)
  27
  28   # Setup correct types for all args and returns
  29   # even if only passing, to avoid truncation etc.
  30   dirp = ctypes.c_void_p
  31   direntp = ctypes.POINTER(dirent)
  32
  33   libc.readdir.argtypes = [dirp]
  34   libc.readdir.restype = direntp
  35
  36   libc.opendir.restype = dirp
  37
  38   # Ensure a file is present
  39   f, fname = tempfile.mkstemp(dir='.')
  40   fname = os.path.basename(fname)
  41
  42   dirp = libc.opendir(".")
  43   if dirp:
  44     while True:
  45       ep = libc.readdir(dirp)
  46       if not ep: break
  47       d_type = ep.contents.d_type
  48       name = ep.contents.d_name
  49       if name == "." or name == "..":
  50         if d_type != DT_DIR: break
  51       # Check files too since on XFS, only dirs have DT_DIR
  52       # while everything else has DT_UNKNOWN
  53       elif name == fname:
  54         if d_type == DT_REG:
  55           fail = 0
  56         break
  57       elif d_type != DT_DIR and d_type != DT_UNKNOWN:
  58         fail = 0
  59         break
  60 except:
  61   pass
  62
  63 try:
  64   if fname:
  65     os.unlink(fname);
  66 except:
  67   pass
  68
  69 sys.exit(fail)