
#!/usr/bin/env python
# -*- coding: utf-8 -*-

'''
利用pexpect实现人机交互
'''

import pexpect
PROMPT = ['# ', '>>> ', '> ', '\$ ']

def send_command(child, cmd):
  child.sendline(cmd)
  child.expect(PROMPT)
  print(child.before)

def connect(user, host, password):
  ssh_newkey = 'Are you sure you want to continue connecting'
  connStr = 'ssh ' + user + '@' + host
  child = pexpect.spawn(connStr)
  ret = child.expect([pexpect.TIMEOUT, ssh_newkey, \
  '[P|p]assword:'])
  if ret == 0:
    print('[-] Error Connecting')
    return
  if ret == 1:
    child.sendline('yes')
    ret = child.expect([pexpect.TIMEOUT, ssh_newkey, \
    '[P|p]assword:'])
  if ret == 0:
    print('[-] Error Connecting')
    return
  child.sendline(password)
  child.expect(PROMPT)
  return child

def main():
  host = 'localhost'
  user = 'root'
  password = '<PASSWORD>'
  child = connect(user, host, password)
  send_command(child, 'cat /etc/shadow | grep root')

if __name__ == '__main__':
  main()
