views:

596

answers:

3

Hi All,

I have googled "python ssh". There is a wonderful module "pexpect", which can access a remote computer using ssh (with password).

After the remote computer is connected, I can execute other commands. However I cannot get the result in python again.

p = pexpect.spawn("ssh user@remote_computer")
print "connecting..."
p.waitnoecho()
p.sendline(my_password)
print "connected"
p.sendline("ps -ef")
p.expect(pexpect.EOF) # this will take very long time
print p.before

How to get the result of "ps -ef" in my case?

Regards

A: 

Try to send

p.sendline("ps -ef\n")

IIRC, the text you send is interpreted verbatim, so the other computer is probably waiting for you to complete the command.

Aaron Digulla
A: 

You might also want to investigate paramiko which is another SSH library for Python.

jgeewax
+3  A: 

Have you tried an even simpler approach?

>>> from subprocess import Popen, PIPE
>>> stdout, stderr = Popen(['ssh', 'user@remote_computer', 'ps -ef'],
...                        stdout=PIPE).communicate()
>>> print(stdout)

Granted, this only works because I have ssh-agent running preloaded with a private key that the remote host knows about.

Pavel Repin
Thanks for this tip. Is there an easy way to configure private keys for many clients? I have to check log files of 20 machines every week. This is the motivation of writing a python script.
stanleyxu2005
Well... you'll just have to append your public key to ~/.ssh/authorized_keys on each of the machines. Perhaps, if your working set of machines doesn't change a lot, this will be a one time exercise.BTW, this is a pretty neat article about setting up SSH Agent and more:http://unixwiz.net/techtips/ssh-agent-forwarding.html
Pavel Repin