tyshell

   1 #!/usr/bin/python3
   2 import os
   3 import readline
   4 import shlex
   5 import sys
   6 import subprocess
   7 import socket
   8 import pwd
   9 import grp
  10
  11 tuerSock = "/run/tuer.sock"
  12
  13 # use a histfile
  14 histfile = os.path.join(os.path.expanduser("~"), ".tyshellhist")
  15 try:
  16     readline.read_history_file(histfile)
  17 except IOError:
  18     pass
  19 import atexit
  20 atexit.register(readline.write_history_file, histfile)
  21
  22 # available commands
  23 def helpcmd(c):
  24         print("Available commands: %s" % ", ".join(sorted(commands.keys())))
  25
  26 def extcmd(cmd):
  27         def run(c):
  28                 ret = subprocess.call(cmd)
  29                 if ret != 0:
  30                         print("Command returned non-zero exit statis %d" % ret)
  31         return run
  32
  33 def sendcmd(addr, cmd):
  34         def run(c):
  35                 print("206 Sending command %s..." % (cmd))
  36                 s = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
  37                 s.connect(addr)
  38                 s.settimeout(60.0)
  39                 s.send(cmd.encode())
  40                 data = s.recv(256)
  41                 s.close()
  42                 print(data.decode('utf-8'))
  43         return run
  44
  45 def exitcmd(c):
  46         print("Bye")
  47         return True
  48
  49 def whocmd(c):
  50         for n in grp.getgrnam("tuer").gr_mem:
  51                 p = pwd.getpwnam(n)
  52                 print (p.pw_name, " - ", p.pw_gecos)
  53
  54 def alias (cmds, aliases):
  55         for newname, oldname in aliases.items():
  56                 cmds[newname] = cmds[oldname]
  57         return cmds
  58
  59 commands = alias({
  60         'exit': exitcmd,
  61         'help': helpcmd,
  62         'open': sendcmd(tuerSock, 'unlock'),
  63         'buzz': sendcmd(tuerSock, 'buzz'),
  64         'who': whocmd,
  65 },{
  66         # aliases
  67         'unlock': 'open',
  68 })
  69
  70 def complete_command(cmd):
  71         '''returns a list of commands (as strings) starting with cmd'''
  72         return list(filter(lambda x: x.startswith(cmd), commands.keys()))
  73 readline.set_completer(lambda cmd, num: (complete_command(cmd)+[None])[num]) # wrap complete_command for readline's weird completer API
  74 readline.parse_and_bind("tab: complete") # run completion on tab
  75
  76 # input loop
  77 print("Welcome to tyshell. Use help to see what you can do.")
  78 while True:
  79         try:
  80                 command = input("$ ")
  81         except EOFError:
  82                 print()
  83                 break
  84         command = shlex.split(command)
  85         if not len(command): continue
  86         # find suiting commands
  87         if command[0] in commands: # needed in case a complete command is a prefix of another one
  88                 cmdoptions = [command[0]]
  89         else:
  90                 cmdoptions = complete_command(command[0])
  91         # check how many we found
  92         if len(cmdoptions) == 0: # no commands fit prefix
  93                 print("Command %s not found. Use help." % command[0])
  94         elif len(cmdoptions) == 1: # exactly one command fits (prefix)
  95                 try:
  96                         res = commands[cmdoptions[0]](command)
  97                         if res: break
  98                 except Exception as e:
  99                         print("Error while executing %s: %s" % (command[0], str(e)))
 100         else: # multiple commands fit the prefix
 101                 print("Ambiguous command prefix, please choose one of the following:")
 102                 print("\t", " ".join(cmdoptions))
 103                 # TODO: put current "command[0]" into the shell for the next command, but such that it is deletable with backspace
 104