python pexpect 学习与探索

 

1.pexpect  module 安装

 

 

　　pexpect属于第三方的，所以需要安装，

 

      

 

　　　　

 

tar -xzvf  pexpect-3.3.tar.gz 

cd pexpect-3.3 

python setup install (require root)

但是 这个安装需要root权限，如果没有root权限在，还能使用吗？

 

　　答案是肯定的，你只需要把lib的路径放入sys.path。这样便可以使用pexpect

 

#!/usr/bin/env python

import sys

sys.path.append('pexpect-3.3/build/lib')

 

　　确认安装成功：

 

　　　　

 

>>> import pexpect

>>> dir(pexpect)

['EOF', 'ExceptionPexpect', 'PY3', 'TIMEOUT', '__all__', '__builtins__', '__doc__', '__file__', '__name__', '__package__', '__path__', '__revision__', '__version__', '_run', 'codecs', 'errno', 'fcntl', 'is_executable_file', 'os', 'pty', 're', 'resource', 'run', 'runu', 'searcher_re', 'searcher_string', 'select', 'signal', 'spawn', 'spawnu', 'split_command_line', 'stat', 'struct', 'sys', 'termios', 'time', 'traceback', 'tty', 'types', 'which']

 

 

 

2.使用方法

 

　　run 函数,run函数和os。system()差不多，所不同的是os.system返回的是整数，而run返回字符串

 

　　

 

复制代码

>>> print pexpect.run('ping localhost -c 3')           

PING localhost (127.0.0.1) 56(84) bytes of data.

64 bytes from localhost (127.0.0.1): icmp_seq=1 ttl=64 time=0.087 ms

64 bytes from localhost (127.0.0.1): icmp_seq=2 ttl=64 time=0.088 ms

64 bytes from localhost (127.0.0.1): icmp_seq=3 ttl=64 time=0.088 ms

 

--- localhost ping statistics ---

3 packets transmitted, 3 received, 0% packet loss, time 2002ms

rtt min/avg/max/mdev = 0.087/0.087/0.088/0.010 ms

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 spawn 类是通过生成子程序sendline发送命令与expect拿回返回进行交互

 

import pexpect

child = pexpect.spawn('python',timeout=3)

child.expect(">>>")

child.sendline("exit()")

print child.before   # Print the result of the ls command.

 

timeout是等待时间，如果超过就会抛出exception，可以 使用except关键字捕获

 

　　

 

 

 

设置log

 

 

 

fout=file('filename','a') #w write /a append

child = pexpect.spawn('su root')

child.logfile = sys.stdout

child.logfile_send=fout

 

 

　　

 

 

 

 

 

复制代码

#!/usr/bin/python 

'''

this script can batch add user 

everytime will add specific usename

user mumber and password

create by Young 2014/08/02

require pexpect module, if you don't have one 

please install this module 

if you can't install this module please 

add  this module path to sys.path

'''

import pexpect

import getopt

import os

import sys

import random

import string

 

# usage fuction

def usage():

    print '''

Usage: python %s  --name user --amount 100 --password [optional]

or python %s  -n user -a 100 -p [optional]

this will create user1~user100 and default password will be random or specific.

make sure when you run this script as root 

-n,--name        the username you want create

-a,--amount      the amount of users you want create

-p,--password    the default password of use your create

-h,--help        display this help and exit

-v,--version     output version information and exit

'''  %(sys.argv[0],sys.argv[0])

# get the parameters 

# set the default user name

user_name='user'

# generate random password

def set_password():

    word=[x for x in 'aAbBcCdDeEfFgGhHiIjJkKlLmMnNoOpPqQrRsStTuUvVwWxXyYzZ0123456789']

    p=string.join(random.sample(word, 8)).replace(" ","")

    return p

# number of users ,set default users number as 10

number_of_users=10

password=set_password()

is_ramdom_password=True

#print password

def get_command():

    try:

        opts, args = getopt.getopt(sys.argv[1:], "n:a:p:hv", ["name=","amount=","password=","help", "version"])

    except getopt.GetoptError as err:

        # print help information and exit

        print str(err) # will print something like "option -a not recognized"

            usage()

            sys.exit(2)

    #print opts,args

    for option,value in opts:

        #print "----------->"+option+' <><>'+value

            if option in ["-n","--name"]:

            if(len(value)>=4):

                global user_name

                user_name=value

            else:

                print "invaild usename,will use user"

        elif option in ["-a","--amount"]:

            if value.isdigit():

                if( int(str(value))>0 and int(str(value))< 1000 ):

                    global number_of_users

                    number_of_users=int(str(value))

                else:

                    usage()

                    sys.exit(2)

            else:

                print "ValueError: invalid literal for ",value

                print "invaild amount,will use defualt"

        

        elif option in ["-p","--password"]:

            if(len(value)>=6):

                global password

                password=value    

                global is_ramdom_password

                is_ramdom_password=False

            else:

                print "invaild password,will use random"

        elif option in ["-v","--version"]:

                    print sys.argv[0]+' 1.0.0'

            sys.exit(0)

               elif option in ("-h", "--help"):

                    usage()

                    sys.exit(0)

               else :

            assert False, "unhandled option"

            usage()

            sys.exit(2)

def check_root():

    if( os.environ['USER']!='root'):

        print 'Permission denied,please su root'

        sys.exit()

#use pexpect to adduser

def run_add(user,mypassword):

    log = file('adduser.log','a')

    flag=os.system('adduser '+user)

    if(flag!=0):

        os.system('userdel '+user)

        os.system('adduser '+user)

    try:

        child=pexpect.spawn('passwd '+user,timeout=5)

        child.logfile = log

        child.logfile_send=sys.stdout 

        child.expect("New password:")

        child.sendline(mypassword)

        child.expect("Retype new password:")

        child.sendline(mypassword)

        child.expect("passwd: all authentication tokens updated successfully.")

    except pexpect.EOF:

        pass

    except pexpect.TIMEOUT:

        pass

 

    

def add_user(name,amount,password,is_ramdom_password):

    check_root()

    for number in range(1,amount+1):

        if(is_ramdom_password):

            print "%4d: adduser %s%-4d password %s " %(number,name,number,set_password())    

            run_add(name+str(number),set_password())

        else:

            print "%4d: adduser %s%-4d password %s " %(number,name,number,password)

            run_add(name+str(number),set_password)

        

 

get_command()

add_user(user_name,number_of_users,password,is_ramdom_password)