Question

I’ve created an expect script that, when executed, ssh’s onto a server and executes a series of commands. Pseudocode looks like this:

#!/usr/bin/expect
spawn ssh usr@myip
expect "password:"
send "mypassword\n";
send "./mycommand1\r"
send "./mycommand2\r"
interact

When executed from a bash shell ($ ./myscript.txt) the code executes fine. What I would now like to do is have a line in python file that runs the commands in the script the same way the bash shell does. Pseudocode looks like this:

import subprocess
def runmyscript():
    subprocess.call("myscript.txt", executable="expect", shell=True)
def main():
    run = runmyscript():
if __name__ == '__main__': main()   

I have placed the myscript.txt script file in the same directory as my runmyscript.py file, yet when I run the python file I receive the error:

WindowsError: [Error 2] The system cannot find the file specified

I’ve read through the documentation on the python.org site, but to no avail. Does anyone have a cunning solution for executing bash scripts from within .py code?

SOLUTION: this code works for me.

child = subprocess.Popen(['bash', '-c', './myscript.txt'], stdout = subprocess.PIPE)

Used this code to call an Expect file to ssh and send commands to server from .py file – useful solution if you are having trouble getting pycrypto/paramiko built onto your machine.

Answer 1

Here is a python implementation of your expect script:

import paramiko

user = "user"
pass = "pass"
host = "host"

client = paramiko.SSHClient()
client.load_system_host_keys()
client.set_missing_host_key_policy(paramiko.AutoAddPolicy())
client.connect(host, port=22, username=user, password=pass)
client.exec_command("./mycommand1")
client.exec_command("./mycommand2")
client.close()