Modifying user attributes

So we are not happy that the default shell for user tom is /bin/sh, and we want to change it to /bin/bash. We can use the usermod command to modify user attributes.

For example, to change the default shell for user tom to be /bin/bash, you can run the command usermod -s /bin/bash tom:

root@ubuntu-linux:~# usermod -s /bin/bash tom

Notice that you can also use the full name for the command option; so you can use --shell instead of -s. Anyways, let's see if we successfully changed the default shell for user tom:

root@ubuntu-linux:~# su - tom 
tom@ubuntu-linux:~$ whoami 
tom
tom@ubuntu-linux:~$ echo $SHELL
/bin/bash

Great! We successfully did it. You can also change the UID of tom to 444 by running the command usermod -u 444 tom:

root@ubuntu-linux:~# usermod -u 444 tom

And we can indeed check that the UID of tom has changed by taking a peek at the /etc/passwd file:

root@ubuntu-linux:~# tail -n 2 /etc/passwd 
tom:x:444:1007::/home/tom:/bin/bash 
jerry:x:777:1008:Jerry...