Python - Telnet


Advertisements

Telnet is a type of network protocol which allows a user in one computer to logon to another computer which also belongs to the same network. The telnet command is used along with the host name and then the user credentials are entered. Upon successful login the remote user can access the applications and data in a way similar to the regular user of the system. Of course some privileges can be controlled by the administrator of the system who sets up and maintains the system.

In Python telnet is implemented by the module telnetlib which has the Telnet class which has the required methods to establish the connection. In the below example we also use the getpass module to handle the password prompt as part of the login process. Also we assume the connection is made to a unix host. The various methods from telnetlib.Telnet class used in the program are explained below.

  • Telnet.read_until - Read until a given string, expected, is encountered or until timeout seconds have passed.

  • Telnet.write - Write a string to the socket, doubling any IAC characters. This can block if the connection is blocked. May raise socket.error if the connection is closed.

  • Telnet.read_all() - Read all data until EOF; block until connection closed.

Example

import getpass
import telnetlib

HOST = "http://localhost:8000/"
user = raw_input("Enter your remote account: ")
password = getpass.getpass()

tn = telnetlib.Telnet(HOST)

tn.read_until("login: ")
tn.write(user + "\n")
if password:
    tn.read_until("Password: ")
    tn.write(password + "\n")

tn.write("ls\n")
tn.write("exit\n")

print tn.read_all()

When we run the above program, we get the following output −

 - lrwxrwxrwx    1 0        0               1 Nov 13  2012 ftp -> .
- lrwxrwxrwx    1 0        0               3 Nov 13  2012 mirror -> pub
- drwxr-xr-x   23 0        0            4096 Nov 27  2017 pub
- drwxr-sr-x   88 0        450          4096 May 04 19:30 site
- drwxr-xr-x    9 0        0            4096 Jan 23  2014 vol

Please note that this output is specific to the remote computer whose details are submitted when the program is run.

Useful Video Courses


Video

Python Online Training

Most Popular

187 Lectures 17.5 hours

Malhar Lathkar

Video

Python Essentials Online Training

55 Lectures 8 hours

Arnab Chakraborty

Video

Learn Python Programming in 100 Easy Steps

136 Lectures 11 hours

In28Minutes Official

Video

Python with Data Science

75 Lectures 13 hours

Eduonix Learning Solutions

Video

Python 3 from scratch to become a developer in demand

70 Lectures 8.5 hours

Lets Kode It

Video

Python Data Science basics with Numpy, Pandas and Matplotlib

63 Lectures 6 hours

Abhilash Nelson

Advertisements