Question

in Python glob ignores “Permission denied” errors. Unfortunately I need to know if there was a directory which I can’t read.

I could use os.walk() and fnmatch, but maybe there is a better solution?

Example:

user@pc:~
===> python
>>> import glob
>>> glob.glob('/root/*')
[]

There are files in /root, but user@pc is not allowed to read this directory.

A single Exception would not be enough. For example glob.glob('/var/log/*/*.log'). I want to know which directories exist, but are unreadable.

Answer 1

One way to get all the directories and files that cannot be read is indeed use os.walk to traverse recursively a directory tree and then, for every directory and file, check permissions using os.access:

import os

unreadable_dirs = []
unreadable_files = []

for dirpath, dirnames, filenames in os.walk('/var/log'):
  for dirname in dirnames:
    dirname = os.path.join(dirpath, dirname)
    if not os.access(dirname, os.R_OK):
      unreadable_dirs.append(dirname)
  for filename in filenames:
    filename = os.path.join(dirpath, filename)
    if not os.access(filename, os.R_OK):
      unreadable_files.append(filename)

print 'Unreadable directories:\n{0}'.format('\n'.join(unreadable_dirs))
print 'Unreadable files:\n{0}'.format('\n'.join(unreadable_files))

Note: You could write your own recursive function that traverses the directory structure, but you’ll be basically duplicating os.walk functionality, so I don’t see the use case for glob.glob.