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.
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