Python Telnetlib Module
The telnetlib module provides a Telnet client class that implements the Telnet protocol.
Note: The telnetlib module is deprecated as of Python 3.11 and was removed in Python 3.13. It is recommended to use external libraries like telnetlib3 or asyncio for network communication.
Importing the Module
import telnetlib
Basic Usage
To connect to a Telnet server:
import telnetlib
HOST = "localhost"
user = "user"
password = "password"
tn = telnetlib.Telnet(HOST)
tn.read_until(b"login: ")
tn.write(user.encode('ascii') + b"\n")
tn.read_until(b"Password: ")
tn.write(password.encode('ascii') + b"\n")
tn.write(b"ls\n")
tn.write(b"exit\n")
print(tn.read_all().decode('ascii'))
Debugging
You can set a debug level to see the communication details.
tn.set_debuglevel(1)
Methods
read_until(expected, timeout=None): Read until a given byte string,expected, is encountered or untiltimeoutseconds have passed.read_all(): Read all data until EOF; block until connection closed.write(buffer): Write a byte string to the socket.interact(): Interaction function, emulates a very dumb Telnet client.