我想编写一个程序(在Windows 7上的Python 3.x中),它通过ssh在远程shell上执行多个命令.在查看paramikos的exec_command()函数之后,我意识到它不适合我的用例(因为在执行命令后通道被关闭),因为命令依赖于环境变量(由先前的命令设置)并且不能连接到一个exec_command()调用,因为它们将在程序中的不同时间执行.

因此,我想在同一个通道中执行命令.我研究的下一个选项是使用paramikos的invoke_shell()函数实现交互式shell：

ssh = paramiko.SSHClient()

ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())

ssh.connect(host, username=user, password=psw, port=22)

channel = ssh.invoke_shell()

out = channel.recv(9999)

channel.send('cd mivne_final\n')

channel.send('ls\n')

while not channel.recv_ready():

time.sleep(3)

out = channel.recv(9999)

print(out.decode("ascii"))

channel.send('cd ..\n')

channel.send('cd or_fail\n')

channel.send('ls\n')

while not channel.recv_ready():

time.sleep(3)

out = channel.recv(9999)

print(out.decode("ascii"))

channel.send('cd ..\n')

channel.send('cd simulator\n')

channel.send('ls\n')

while not channel.recv_ready():

time.sleep(3)

out = channel.recv(9999)

print(out.decode("ascii"))

ssh.close()

这段代码存在一些问题：

>第一次打印并不总是打印ls输出(有时它只打印在第二次打印时).

>第一个cd和ls命令始终存在于输出中(我通过recv命令获取它们,作为输出的一部分),而有时会打印以下所有cd和ls命令,有时它们不会.

>第二个和第三个cd和ls命令(打印时)总是出现在第一个ls输出之前.

我对这种“非决定论”感到困惑,非常感谢你的帮助.

最佳答案

import paramiko

import re

class ShellHandler:

def __init__(self, host, user, psw):

self.ssh = paramiko.SSHClient()

self.ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())

self.ssh.connect(host, username=user, password=psw, port=22)

channel = self.ssh.invoke_shell()

self.stdin = channel.makefile('wb')

self.stdout = channel.makefile('r')

def __del__(self):

self.ssh.close()

def execute(self, cmd):

"""

:param cmd: the command to be executed on the remote computer

:examples: execute('ls')

execute('finger')

execute('cd folder_name')

"""

cmd = cmd.strip('\n')

self.stdin.write(cmd + '\n')

finish = 'end of stdOUT buffer. finished with exit status'

echo_cmd = 'echo {} $?'.format(finish)

self.stdin.write(echo_cmd + '\n')

shin = self.stdin

self.stdin.flush()

shout = []

sherr = []

exit_status = 0

for line in self.stdout:

if str(line).startswith(cmd) or str(line).startswith(echo_cmd):

# up for now filled with shell junk from stdin

shout = []

elif str(line).startswith(finish):

# our finish command ends with the exit status

exit_status = int(str(line).rsplit(maxsplit=1)[1])

if exit_status:

# stderr is combined with stdout.

# thus, swap sherr with shout in a case of failure.

sherr = shout

shout = []

break

else:

# get rid of 'coloring and formatting' special characters

shout.append(re.compile(r'(\x9B|\x1B\[)[0-?]*[ -/]*[@-~]').sub('', line).

replace('\b', '').replace('\r', ''))

# first and last lines of shout/sherr contain a prompt

if shout and echo_cmd in shout[-1]:

shout.pop()

if shout and cmd in shout[0]:

shout.pop(0)

if sherr and echo_cmd in sherr[-1]:

sherr.pop()

if sherr and cmd in sherr[0]:

sherr.pop(0)

return shin, shout, sherr