Ubuntu Unleashed 2019 Edition: Covering 18.04, 18.10, 19.04

#   User    privilege   specification

root    ALL=(ALL:ALL)   ALL

#   Members of  the admin   group   may gain    root    privileges

%admin  ALL=(ALL)   ALL

#   Allow   members of  group   sudo    to  execute any command

%sudo   ALL=(ALL:ALL)   ALL

#   See sudoers(5)  for more    information on  "#include"  directives:

#includedir /etc/sudoers.d

After your fix is complete, exit the root command line:

root@seymour:~# exit

You return to the recovery mode menu. Select Resume Normal Boot to finish
and return to a normal boot. When the boot completes, you should be able to
use sudo correctly again.

Creating Users

When a Linux system administrator creates a user, an entry is created in
/etc/passwd for the user. The system also creates a directory, labeled with
the user’s username, in the /home directory. For example, if you create a user
named sandra, the user’s home directory is /home/sandra.

NOTE

In  this    chapter,    you learn   how to  manage  users   from    the command line.   See

Chapter 13, “Managing   Users,” for more    information on  user

administration, including   administration  using   graphical   administration

utilities.

Use the adduser command, along with a user’s name, to quickly create a
user:

Click here to view code image
matthew@seymour:~$ sudo adduser sandra

After creating a user, you must also create the user’s initial password with the
passwd command:

Click here to view code image
matthew@seymour:~$ sudo passwd sandra