如何用python开发一个ssh客户端工具

1）通过paramiko的ssh模块连接指定主机；

2) 通过SSHClient.exec_command在远程主机上执行命令；

3）通过exec_command返回的stdout,stdin,stderr进行交互；

4）保存成功连接的主机信息（session），可以通过ls命令查看， session id命令，直接启动新连接；

5）可在windows和linux下运行，写程序时需要注意他们的差别。
代码ssh.py

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

import os,sys
import paramiko
import threading
import platform

curr_ssh = None
curr_prompt = ">>"

#使用说明
def printUsage():
print "    !ls                     :list sessions."
print "    !session id             :connect session."
print "    !conn host user password:connect host with user."
print "    !exit                   :exit."

#连接
def conn(ip,username,passwd):
try:
ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
ssh.connect(ip,22,username,passwd,timeout=5)
print "Connect to ",ip," with ",username
global curr_prompt
curr_prompt=username+"@"+ip+">>"
return ssh
except:
return None

#加载以前的连接信息
sessions=[]
def loadSessions():
global sessions
try:
f = open("sessions")
sessions = f.readlines()
f.close()
except:
pass

#执行本地命令,ssh.py的命令
def exe_cmd_local(cmd):
if(cmd == "!ls"):
loadSessions()
global sessions
i=0
print "Sessions:"
for s in sessions:
print"[%d] %s" %(i,s)
i+=1
else:
vals = cmd.split(' ')
if(vals[0]=="!session"):
id = (int)(vals[1])
if(id<len(sessions)): os_name="platform.system()" new_console_cmd="" if(os_name="=" "linux"):="" .="" ssh.py="" "="" +="" sessions[id]+"\""="" elif(os_name="=" "windows"):="" sessions[id]="" os.system(new_console_cmd)="" else:="" print="" "didn't="" hava="" sessoin="" ",vals[1]="" elif(vals[0]="="!conn"):" global="" curr_ssh="" f="open("sessions","a")" line="vals[1]+"" "+vals[2]+"="" "+vals[3]+"\n"="" f.write(line)="" f.close()="" #在ssh连接的主机上执行命令="" def="" exe_cmd_ssh(ssh,cmd):="" if(ssh="=" none):="" connect="" to="" a="" server.="" use="" '!conn'="" please."="" return="" stdin,="" stdout,="" stderr="ssh.exec_command(cmd)" #stdin.write("y")="" #简单交互，输入="" ‘y’="" #屏幕输出="" stdout.read()="" stderr.read()="" #入口函数="" if="" __name__="='__main__':" loadsessions()="" if(len(sys.argv)="=4):" printusage()="" while="" true:="" cmd="raw_input(curr_prompt)" if(len(cmd)="=0):" continue="" if(cmd="=" "!exit"):="" if(curr_ssh="" !="None):" curr_ssh.close();="" break="" if(cmd[0]="=" '!'):="" exe_cmd_local(cmd)="" exe_cmd_ssh(curr_ssh,cmd)<="" pre="">