2) Root users:
Root users are the ones who are the administrators of the system. They are
called super users and have an Id which is 0. Root users can write and
modify any part of the file. If a hacker can get access to a root user account,
then he can completely delete the files that are present. Usually,
server
administrators are Superusers, so it is very
tough for hackers to get
administrative privileges of a system.
3) System users
System users are not real users but users that are created by the programs
that are run in the system. For example, when the
Chrome browser is started
certain system processes will start with the name of system Id. It is
important to track and sort these system IDs for better usage of the user
system that Linux provides.
Below we will give a command that will help us understand the Linux user
system:
linuxexample @ host: systemid 2344
Apart from users Linux also offers group systems. Groups are important for
the management of a huge number of users working on the same project. It
also helps to organize things in a better way. By default, every user in the
Linux system belongs to a group.
Every group is represented by GID in Linux. The only Root user can create
groups and organize them in a definite way. However, a user can be in one
or more groups according to specifications.
Below we give some commands which can help to know your current user
ID and group id:
linuxexample @ host : get UID
linuxexample @ host :
get GID
As discussed earlier every Linux system account needs a username and
password. Passwords, as we all know, are prone to attacks and are the first
thing that can be tried to exploit. Passwords can give one-way access to all
the sensitive information for hackers.
Linux usually holds all passwords in two files. They are
1) /etc/passwor d
2) /etc/shadow
The first one stores the password of the current user and can be easily read
by the user.
Whereas the second one is more sensible and contains passwords of all the
users in the system. This can be only read by the root user and will not be
visible for normal users.
In the next section, we will describe various commands that can help us to
modify user groups. Follow along:
