How do I switch from root user to another user who has a nologin shell?

Question

I'm just learning linux. Working as root, I created a new user called testuser. I then changed testuser to a nologin shell.

Now I want to login as the testuser to see what a user with a nologin shell can/can't do.

I tried: su testuser and got: This account is currently not available. I tried: su - testuser and got: su: warning: cannot change directory to /home/testuser: No such file or directory This account is currently not available.

How do I switch from root to a user with a nologin shell?

Answer 1

The point of the nologin shell is to prevent the user from logging in. Such a user may still use your server services like FTP, IMAP/POP3 and others but they won't be able to login e.g. using sshd or console, period.

How do I switch from root to a user with a nologin shell?

sudo -u USERNAME /bin/bash

Will work but only root can do that.

Answer 2

Artem's answer is good, but if sudo isn't available, it is also possible to use

su --shell /bin/bash USERNAME

From the su manual about the -s/--shell flag:

If the target user has a restricted shell (i.e. the shell field of this user's entry in /etc/passwd is not listed in /etc/shells), then the --shell option or the $SHELL environment variable won't be taken into account, unless su is called by root.