Why is an output of some commands (like an order of files in "ls" listing) different in Paramiko compared to manual SSH session?

Question

When we send command using ssh.exec_command of Paramiko library of Python. After that we receive three parameter as output: stdin, stdout, stderr. So I want to compare the output of stdout with existing list. So on what basis the sorting of stdout result happen if I what to compare it?

Answer 1

If you are referring to commands like ls, you may get different results based on environment variables set.

And you can get different environments based on whether a terminal is allocated for the session.

With Paramiko SSHClient.exec_command with the get_pty parameter with the default value False, you should get the same results as with:

ssh user@host command

If you set get_pty to True, you get the same results as with:

ssh -T user@host command

But you should not set get_pty=True, as your code can then break when the environment changes.

Related questions with more details:

• Environment variable differences when using Paramiko
• What is the difference between exec_command and send with invoke_shell() on Paramiko?