How to get terminal output?

Question

Background

As a fun project, I have decided to create a remote control application for my new Raspberry Pi. I know how to use SSH, but I wanted to implement somthing similar in Python. How can I get the text that is printed out onto the terminal to display in my Python shell?

I checked out this SO question, but it did not work. By did not work, I mean that I am not able to see the output text. If I enter passwd, it gives me only

Changing password for User.

But it does not give me the interactive session. THAT is what I am trying to figure out.

NOTE: my Raspberry Pi is running on “Wheezy.” Also, it would be great if this program could work with other operating systems (such as Windows 7, Mac OS X).

Code

import subprocess
import socket
import sys
import platform
import os

print "WELCOME TO xTROL. \n"

pyVER = sys.version
OS = platform.system()

print pyVER, "\n"
print "Running on %s" % (OS)
while True:
    INPUT = raw_input(">>>")
    cmd_FORMAT = INPUT.split()

    try:
        output = subprocess.Popen(cmd_FORMAT, stdout=subprocess.PIPE).communicate()[0]
        print output
    except Exception:
        print "Something went wrong."

Can you show us exactly what you're doing so we can help diagnose? — Kyle Maxwell, Apr 01 '13 at 00:15
@xxmbabanexx Maybe you're doing something wrong, As Kyle said it's better to show what you're doing exactly. — MostafaR, Apr 01 '13 at 00:20
@MostafaR Ok, this is *exactly* what I did. I used the `Popen` subprocess command, and did the code as above. When I execute a terminal command, *nothing* happens. — xxmbabanexx, Apr 01 '13 at 00:27
@KyleMaxwell I have shown you *exactly* what I have done. If you need extra information, please tell me what it is. — xxmbabanexx, Apr 01 '13 at 00:28
`cmd` is not defined in this code. Otherwise, it should work unless your commands do not output anything in stdout. — wRAR, Apr 01 '13 at 00:32
For me it works for simple commands (Of course by changing cmd_FORMAT to cmd), But i think it have bugs with complex command lines. You can show us what is the command that you're trying to run. — MostafaR, Apr 01 '13 at 00:41
@MostafaR I tried to run Python from the Terminal (Just put "Python" into the code). When I do this, it only returns a blank line. — xxmbabanexx, Apr 01 '13 at 00:42
Yes, that's expected. Interactive programs do not work this way. — wRAR, Apr 01 '13 at 00:43
This is interesting. I ran the file thru ssh, and it works perfectly. Why is this? — xxmbabanexx, Apr 01 '13 at 02:26

score 0 · Answer 1 · answered Apr 01 '13 at 00:46

0

If you want to write something like SSH, you'll have to make a pseudo-terminal. Look at the pty module.

answered Apr 01 '13 at 00:46

icktoofay

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How to get terminal output?

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