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