THE DEV CAVE

SORCERER-SEE

Topic

Users and Groups Management

In general, operating systems, are used by more than one person. This certainly was the case before the rise of the personal computer (PC). To make sharing possible while also protecting the work of individual users to protect the consistency of the overall system, against mistakes by individual users, operating systems provide a password protected user account for each.

• Root

Among all users of a system, one user is the final responsible for the system as a whole. This user has 'root' permissions. This means that he/she can access all parts of the system and can conduct all kinds of operations.

• Permissions

Other users are of the same level by default. By default they can not access critical parts of the system. But the root user can give other users different degrees of access. Users can also be organized in groups and as such share permissions with all members of the group they are in. Every entity in UNIX systems is treated as a file. Each file has three attributes: User(aka Owner), Group, and (all)Other. Each of these can have the following degrees of access (permissions): Read(r), Write(w), Execute(x) and No Permissions Set(-).

Within commandline, which is text-only, a file and its permissions are represented as follows:



For example:



• To be continued...