Python - Executing multiple shell commands one after another

Question

I want to execute multiple shell commands one after another. The commands are received from a remote device through socket. What i need to do is to create a shell that is accessible remotely. With subprocess.Popen i am able to execute commands and get output. But if i want to execute cd MyDIR and then ls -l. If I execute it as 2 lines of code, i get file listing of the parent directory rather than the the directory i cd into. Using cd MyDIR && ls -l gives the required result. If i use the communicate method, i am not getting any result and also the stdin gets closed. Can someone help me with a piece of code?

Edit

The solution given here Interacting with bash from python doesn't solve my problem as i want to keep the shell active as long as possible and as much as needed. Trying the solution on that pages gives a message that IO operation on closed file.

Possible duplicate of [Interacting with bash from python](http://stackoverflow.com/questions/9673730/interacting-with-bash-from-python) — Patrick Haugh, Jan 13 '17 at 13:57
@PatrickHaugh Yes it looks like a duplicate but i want to solve the `IO operation on closed file` error. I want to keep the communication active. — Kishor V, Jan 13 '17 at 14:12
Looks like it can be done easier if you'll listen with bash. Just `nc -k -l 4444 | bash`. — Raz, Jan 13 '17 at 15:05
@Raz I cant listen with `nc -k -l 4444 | bash` Because, bash is only a part of what i want to do. I am actually trying to run shell commands using Telegram bot. I will remotely send the command and bot executes it on my RPI and it will send me back the response. This is what i actually need. — Kishor V, Jan 13 '17 at 16:44
May be you can start tmux session and interact with it. Check this [lib](https://github.com/tony/libtmux). It can connect to session and do `pane.send_keys('echo hey send now')`. — Raz, Jan 13 '17 at 16:50

score 1 · Accepted Answer · answered Jan 14 '17 at 06:17

This code helps

from subprocess import Popen, PIPE
from time import sleep
from fcntl import fcntl, F_GETFL, F_SETFL
from os import O_NONBLOCK, read

# run the shell as a subprocess:
p = Popen(['python', 'shell.py'],
        stdin = PIPE, stdout = PIPE, stderr = PIPE, shell = False)
# set the O_NONBLOCK flag of p.stdout file descriptor:
flags = fcntl(p.stdout, F_GETFL) # get current p.stdout flags
fcntl(p.stdout, F_SETFL, flags | O_NONBLOCK)
# issue command:
p.stdin.write('command\n')
# let the shell output the result:
sleep(0.1)
# get the output
while True:
    try:
        print read(p.stdout.fileno(), 1024),
    except OSError:
        # the os throws an exception if there is no data
        print '[No more data]'
        break

Here is the source http://eyalarubas.com/python-subproc-nonblock.html

Python - Executing multiple shell commands one after another

1 Answers1