examples/customization/pwd-cd-and-system/utils.py

   1 """Utility for changing directories and execution of commands in a subshell."""
   2
   3 import os
   4 import shlex
   5 import subprocess
   6
   7 # Store the previous working directory for the 'cd -' command.
   8
   9
  10 class Holder:
  11     """Holds the _prev_dir_ class attribute for chdir() function."""
  12     _prev_dir_ = None
  13
  14     @classmethod
  15     def prev_dir(cls):
  16         return cls._prev_dir_
  17
  18     @classmethod
  19     def swap(cls, dir):
  20         cls._prev_dir_ = dir
  21
  22
  23 def chdir(debugger, args, result, dict):
  24     """Change the working directory, or cd to ${HOME}.
  25     You can also issue 'cd -' to change to the previous working directory."""
  26     new_dir = args.strip()
  27     if not new_dir:
  28         new_dir = os.path.expanduser('~')
  29     elif new_dir == '-':
  30         if not Holder.prev_dir():
  31             # Bad directory, not changing.
  32             print "bad directory, not changing"
  33             return
  34         else:
  35             new_dir = Holder.prev_dir()
  36
  37     Holder.swap(os.getcwd())
  38     os.chdir(new_dir)
  39     print "Current working directory: %s" % os.getcwd()
  40
  41
  42 def system(debugger, command_line, result, dict):
  43     """Execute the command (a string) in a subshell."""
  44     args = shlex.split(command_line)
  45     process = subprocess.Popen(
  46         args,
  47         stdout=subprocess.PIPE,
  48         stderr=subprocess.PIPE)
  49     output, error = process.communicate()
  50     retcode = process.poll()
  51     if output and error:
  52         print "stdout=>\n", output
  53         print "stderr=>\n", error
  54     elif output:
  55         print output
  56     elif error:
  57         print error
  58     print "retcode:", retcode