Python使用pexpect库连接Linux并执行命令的完整示例

核心代码与执行逻辑

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

'''https://www.ibm.com/developerworks/cn/linux/l-cn-pexpect2/index.html'''

import pexpect
import types


username = "root"
ip = "192.168.***.***"
password = "****"
pex = pexpect.spawn('ssh %s@%s' % (username, ip))


def _check(pattern, timeout=120):
  i = pex.expect(pattern, timeout=timeout)
  return i


def sendcr(cmd):
  if pex == None:
    return 0
  n = pex.send("%s\r" % cmd)
  return n


def getexec(cmd):

  child = pexpect.spawn(cmd)
  child.expect(pexpect.EOF)
  return child.before


if __name__ == '__main__':

  checklist1 = [["(?i)Connection refused", False],
         ["(?i)Host key verification failed.", False],
         ["(?i)VENUSTECH AUDIT SYSTEM MA1000", True],
         # ["(?i)#\[/]",True],    # hpux
         ["(?i).+>", True], # windows
         [".+[>$#]\s*$", True], # debian
         ["(?i)Last login", True],
         ["(?i)access denied", False],
         ["(?i)NT_STATUS_LOGON_FAILURE", False],
         ["(?i)are you sure you want to continue connecting", "yes"],
         ["(?i)authentication fail(?!ure)", False],
         ["(?i)connection closed by remote host", False],
         ["(?i)login failed", False],
         ["(?i)login incorrect", False],
         ["(?i)need to be root", False],
         ["(?i)no route to host", False],
         ["(?i)not found", False],
         ["(?i)Bad secrets", False],
         ["(?i)incorrect password", False],
         ["(?i)permission denied", False],
         # ["(?i)terminal type",terminal_type],
         ["This private key will be ignored.", False],
         ["(?i)no route to host", False],
         ["(?i)press 'Enter' key to proceed", "\r"],
         ["(?i)Y/N", 'Y'],
         [pexpect.EOF, False],
         [pexpect.TIMEOUT, False],
         ["(?i)Enter passphrase for key .*:", password],
         ["(?i)assword", password],
         ["(?i)passwd", password],
         ["(?i)sername", username],
         ["(?i)(?<!sful )login", username],
         ["(?i)----------------------------------------------------------------", True]]

  checklist2 = [i[0] for i in checklist1]
  while True:
    i = _check(checklist2)
    print i, checklist1[i], checklist1[i][1]
    if (type(checklist1[i][1]) is types.BooleanType):
      if type(checklist1[i][1]):
        break
    else:
      sendcr(checklist1[i][1])

  cmd = "ls -l /etc/rsyslog.conf"
  result = getexec(cmd)
  print "result", result

26 ['(?i)assword', '***'] ***
5 ['(?i)Last login', True] True
result -rw-r--r--. 1 root root 3167 Mar 13 11:24 /etc/rsyslog.conf