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1231

answers:

7

I'm writing a python script that executes a csh script in Solaris 10. The csh script prompts the user for the root password (which I know) but I'm not sure how to make the python script answer the prompt with the password. Is this possible? Here is what I'm using to execute the csh script:

import commands

commands.getoutput('server stop')
A: 

Should be able to pass it as a parameter. something like:

commands.getoutput('server stop -p password')
Owen
our server stop script doesn't have a -p flag and won't likely be getting one.
+3  A: 

Use subprocess. Call Popen() to create your process and use communicate() to send it text. Sorry, forgot to include the PIPE..

from subprocess import Popen, PIPE

proc = Popen(['server', 'stop'], stdin=PIPE)

proc.communicate('password')

You would do better do avoid the password and try a scheme like sudo and sudoers. Pexpect, mentioned elsewhere, is not part of the standard library.

Douglas Mayle
This doesn't seem to work. I'll continue to investigate popen though.
I get the same response when using the PIPE like you recommend here. The script stops with the Password: prompt.
I don't think that this works because the csh script does exec su root -c "$cmd0 $*"to try to su to root. The su would be a different process than the 'server stop' script.
A: 

This seems to work better:

import popen2

(stdout, stdin) = popen2.popen2('server stop')

stdin.write("password")

But it's not 100% yet. Even though "password" is the correct password I'm still getting su: Sorry back from the csh script when it's trying to su to root.

I think you inverted stdin and stdout.
Federico Ramponi
Nope, from the API: Returns the file objects (child_stdout, child_stdin)
Just some FYI -- popen2 is "Deprecated since version 2.6: This module is obsolete. Use the subprocess module. Check especially the Replacing Older Functions with the subprocess Module section."
monkut
Yeah, I just noticed that. I switched my code back to the subprocess module. Thanks!
@darrick: I incorrectly referred to os.popen2 instead of popen2.popen2. Strangely enough, the order of stdin and stdout is different between the two libraries...
Federico Ramponi
+5  A: 

Have a look at the pexpect module. It is designed to deal with interactive programs, which seems to be your case.

Oh, and remember that hard-encoding root's password in a shell or python script is potentially a security hole :D

Federico Ramponi
Yeah, pexpect was the way to go... I posted the answer at the bottom of this thread.
A: 

To avoid having to answer the Password question in the python script I'm just going to run the script as root. This question is still unanswered but I guess I'll just do it this way for now.

+1  A: 
import pexpect
child = pexpect.spawn('server stop')
child.expect_exact('Password:')

child.sendline('password')

print "Stopping the servers..."

index = child.expect_exact(['Server processes successfully stopped.', 'Server is not running...'], 60)
child.expect(pexpect.EOF)

Did the trick! Pexpect rules!

A: 

add input= in proc.communicate() make it run, for guys who like to use standard lib

from subprocess import Popen, PIPE

proc = Popen(['server', 'stop'], stdin=PIPE)

proc.communicate(input='password')