Page 168 - DCAP602_NETWORK_OPERATING_SYSTEMS_I

Network Operating Systems-I

notes 9.4 keywords

Group List: It is a list of user names of users who are members of the group.

ls command: It is used to view lists of files in any directory to which a user has execute
permission.

9.5 self assessment

Fill in the blanks:
1. The ...................... for /etc/passwd are by default set so that it is world readable, that is, so
that it can be read by any user on the system.
2. User ID is the user’s unique numeric ...................... number, which is used by the system for
access control.
3. In Linux systems, every user must be a member of at least one group, which is identified
by the ...................... of the user’s entry in /etc/passwd.

4. etc/group is a ...................... which defines the groups to which users belong under Linux
and UNIX operating system.
5. Processes run ...................... in Linux and you can kill or suspend different processes using
various commands.
6. The ...................... directory is always the directory that you are put in when you login.
7. All the programs that run under Linux are called as ......................
8. …………………..specifies the user’s principal group identification number.

9. Unix file system permissions are organized into three classes, user, …………, and others.
10. Setting a particular parameter is as simple as typing VARIABLE=………………..
11. The last entry in the PATH command is a …………………..
12. The …………….command is used to view lists of files in any directory to which a user has
execute permission
13. The /etc/shadow file is readable only by the …………….account and is therefore less of a
security risk.

14. The default shell on Linux is………………, whose absolute path is /bin/bash.
15. Each line in /etc/passwd represents a ……………user.

9.6 review Questions

1. In your opinion, what are the permissions for /etc/passwd so that it is world readable?
2. Do you think that the /etc/group file contains the database that lists every group on your
computer and its corresponding GID? State your view with reasons.
3. User ID is the user’s unique numeric identification number, which is used by the system for
access control. Comment

4. Examine the concept of Environment Variables
5. What are the most commonly used ls flags?
6. Elucidate the file system commands used to hold users’ information.

162 LoveLy professionaL university