fs/skeleton/bin/umount-subdirs-of

#!/usr/bin/python
"""umount any mounted subdirs of the given dir, but not that dir."""

import os
import re
import sys


def ReplaceOctals(s):
  def OctalToChr(match):
    code = int(match.group(1), 8)
    return chr(code)
  return re.sub(r'\\(\d\d\d)', OctalToChr, s)


def main():
  if len(sys.argv) != 2:
    sys.stderr.write('usage: %s <dirname>\n' % sys.argv[0])
    sys.exit(99)

  whichdir = sys.argv[1]
  os.chdir(whichdir)
  realwhichdir = os.getcwd()
  whichparts = tuple(realwhichdir.split('/'))

  do_dirs = []
  for line in open('/proc/mounts').readlines():
    dev, path, junk = line.split(' ', 2)
    fixpath = ReplaceOctals(path)
    parts = tuple(fixpath.split('/'))
    if parts[:len(whichparts)] == whichparts and parts != whichparts:
      do_dirs.append(parts)

  rv = 0
  for parts in reversed(sorted(do_dirs)):
    dirname = '/'.join(parts)
    sys.stderr.write('umount %r\n' % dirname)
    if os.spawnvp(os.P_WAIT, 'umount', ['umount', dirname]):
      rv = 1

  sys.exit(rv)


if __name__ == '__main__':
  main()