How can you get the SSH return code using Paramiko?

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最佳答案

SSHClient is a simple wrapper class around the more lower-level functionality in Paramiko. The API documentation lists a recv_exit_status() method on the Channel class.

A very simple demonstration script:

import paramiko
import getpass


pw = getpass.getpass()


client = paramiko.SSHClient()
client.set_missing_host_key_policy(paramiko.WarningPolicy())
client.connect('127.0.0.1', password=pw)


while True:
cmd = raw_input("Command to run: ")
if cmd == "":
break
chan = client.get_transport().open_session()
print "running '%s'" % cmd
chan.exec_command(cmd)
print "exit status: %s" % chan.recv_exit_status()


client.close()

Example of its execution:

$ python sshtest.py
Password:
Command to run: true
running 'true'
exit status: 0
Command to run: false
running 'false'
exit status: 1
Command to run:
$

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A much easier example that doesn't involve invoking the "lower level" channel class directly (i.e. - NOT using the client.get_transport().open_session() command):

import paramiko


client = paramiko.SSHClient()
client.set_missing_host_key_policy(paramiko.AutoAddPolicy())
client.connect('blahblah.com')


stdin, stdout, stderr = client.exec_command("uptime")
print stdout.channel.recv_exit_status()    # status is 0


stdin, stdout, stderr = client.exec_command("oauwhduawhd")
print stdout.channel.recv_exit_status()    # status is 127

小开

Thanks for JanC, I added some modification for the example and tested in Python3, it really useful for me.

import paramiko
import getpass


pw = getpass.getpass()


client = paramiko.SSHClient()
client.set_missing_host_key_policy(paramiko.WarningPolicy())
#client.set_missing_host_key_policy(paramiko.AutoAddPolicy())


def start():
try :
client.connect('127.0.0.1', port=22, username='ubuntu', password=pw)
return True
except Exception as e:
#client.close()
print(e)
return False


while start():
key = True
cmd = input("Command to run: ")
if cmd == "":
break
chan = client.get_transport().open_session()
print("running '%s'" % cmd)
chan.exec_command(cmd)
while key:
if chan.recv_ready():
print("recv:\n%s" % chan.recv(4096).decode('ascii'))
if chan.recv_stderr_ready():
print("error:\n%s" % chan.recv_stderr(4096).decode('ascii'))
if chan.exit_status_ready():
print("exit status: %s" % chan.recv_exit_status())
key = False
client.close()
client.close()

小开

In my case, output buffering was the problem. Because of buffering, the outputs from the application doesn't come out non-blocking way. You can find the answer about how to print output without buffering in here: Disable output buffering. For short, just run python with -u option like this:

> python -u script.py