In Python, check if executed as root

Question

How can I check if my program is running with root permission. Does Pathlib offer the possibility to query the USER-ID under Linux

Answer 1

You can access username with standard library package getpass:

import getpass
print(getpass.getuser())

When code is executed with sudo or as root, the user is the string root.

Answer 2

Use os.geteuid() to check if the effective UID is zero.

import os

if os.geteuid() == 0:
    print("Running as root")

getpass.getuser() is not a reliable solution for a few reasons:

• There can be multiple usernames that map to the superusder userid. If the user logs in with a username other than root the check will fail.
• It uses environment variables by default, which can be manipulated by the user.
• If the code is being run from a set-uid process, its permissions may not match the login username.