core/chdir_browsing.py

   1 import os
   2
   3 # We cannot use a generator because we rely on the finally block to
   4 # be sure _finalize_chdir_browsing will be called. Python 2.5 allows
   5 # finally block in generator, but it relies on the GC so it's not sure
   6 # it will be called at the right time.
   7 #
   8 # The expected use of these browsing functions is:
   9 #
  10 # previous_cwd = chdir_browsing.init(path)
  11 # try:
  12 #     for child in os.listdir('.'):
  13 #         .. Do something with child ..
  14 # finally:
  15 #     chdir_browsing.finalize(previous_cwd)
  16
  17 def init(path):
  18     previous_cwd = os.open('.', os.O_RDONLY)
  19     try:
  20         os.chdir(path)
  21         return previous_cwd
  22     except OSError, e:
  23         os.close(previous_cwd)
  24         raise e
  25
  26 def finalize(previous_cwd):
  27     try:
  28         os.fchdir(previous_cwd)
  29     finally:
  30         os.close(previous_cwd)