You use finger command in order to check user information. What if it's missing?
The official replacement for the original finger command and it’s part of the gnu coreutils package, it is called pinky and it’s available on all systems that use the gnu coreutils.

Well, actually it is not a real replacement of the finger protocol with fingered daemon and finger client. Also, it misses some output information but it is close. Finger was used in the early days of the internet but it is considered obsolete since about 10 years and many Linux distributions do not even install the service nor the client by default anymore.

So, if you find yourself with "finger: command not found", try pinky. The output is similar to who.

root@jupiter:~# pinky
Login    Name                 TTY      Idle   When         Where
root     root                *pts/0           Nov 13 10:25 core
root     root                *pts/1           Nov 13 10:29 core
root@jupiter:~# pinky -l root
Login name: root                        In real life:  root
Directory: /root                        Shell:  /bin/bash

Other alternatives: w and users.