This set of Unix Multiple Choice Questions & Answers (MCQs) focuses on “UNIX”.
1. What is UNIX?
a) an operating system
b) a text editor
c) programming language
d) software program
Explanation: UNIX is an operating system developed in the early 1970’s at Bell Labs by Dennis Ritchie, Ken Thompson, and others. It is a multiuser, multitasking and timesharing operating system. The power of UNIX is derived from its commands and their multiple options.
2. In which language UNIX is written?
Explanation: UNIX was originally written in Assembly language but Dennis Ritchie and Ken Thompson wanted an operating system which could run on more than one type of hardware. So in 1973, they rewrote the whole operating system in C language due to which one of the strongest features i.e. portability was added to the operating system.
3. Which of the following is not a feature of UNIX?
d) easy to use
Explanation: UNIX is a multitasking operating system i.e. a user can run multiple tasks concurrently. Similarly, it is a multiuser system because it permits working with multiple users on a single operating system. But a major disadvantage of UNIX lies in the fact that the richness provided by its commands requires a special type of commitment to understand the subject. i.e. the user must be well aware of commands he is using and the functions performed by them.
4. Which of the following is not a part of all the versions of UNIX?
a) Kernel and Shell
b) Commands and utilities
c) Graphical user interface
d) System Calls
Explanation: The kernel is the heart of the operating system while the shell is the utility which processes our requests. While system calls are a handful of functions which are used to interact with the kernel and make available the services provided by the operating system. A Graphical user interface (GUI) is available in UNIX, but the traditional UNIX interface is the command line only.
5. Which of the following is not true about UNIX?
a) Many people can use a UNIX based computer at the same time; hence UNIX is called as a multiuser system
b) A user can run multiple programs at the same time; hence UNIX is called a multitasking environment
c) UNIX was not written in ‘C’ language
d) Linux is also known as a version of UNIX
Explanation: One of the most attractive features of UNIX is that it supports multi-user and multitasking environment which makes it so popular among its users. There are many UNIX variants available in the market. Solaris Unix, AIX, HP Unix, BSD are some of the examples. Linux is also a flavor of UNIX which is freely available. Unix was developed in 1969 by AT&T employees Ken Thompson, Dennis Ritchie, Douglas McIlroy, and Joe Ossanna at Bell Labs and was written in ‘C’.
6. POSIX is a set of standards specified for establishing compatibility between operating systems.
Explanation: POSIX- Portable Operating System Interface for Computer Environment is basically a set of standards specified by IEEE for establishing compatibility between operating systems, especially which are UNIX based. For example, if we write a program relying on POSIX standards, we can easily port it among a large family of Unix derivatives (including Linux).
7. Shell is a command interpreter used for interacting with a UNIX system.
Explanation: Computers don’t have any capability of translating commands into actions. To do so we require shell-a command interpreter which translates our commands into actions. It is actually the interface between the user and kernel. There could be multiple shells in action on a single system.
8. Which part of the UNIX operating system interacts with the hardware?
c) vi editor
d) application program
Explanation: The kernel is the core of the operating system. It is a collection of routines written in C which directly communicates with the hardware. User programs that need to interact with the hardware access the services of the kernel. There is only one kernel running on a system, unlike shells which can be multiple.
9. Two UNIX systems may or may not use the same set of system calls.
Explanation: All UNIX flavors have one thing in common, they use the same system calls which are described in POSIX specification.
10. What is a superuser?
a) system manager
b) normal user
d) a user with special rights
Explanation: A superuser (root) is the UNIX system manager which can perform special tasks like killing any executing program, resetting other users passwords, change users permissions and performing other system management tasks. The administrator can switch to superuser by issuing su command.
11. What is the windowing system of UNIX known as?
a) X Window system
c) Red Hat
Explanation: The X window system, commonly known as X, is a windowing system developed at MIT. It is an open-source, network transparent, client-server based system that provides a Graphical user interface. X is primarily used on UNIX variants but it is also available for other operating systems also.
Sanfoundry Global Education & Learning Series – Unix.
To practice all areas of Unix, here is complete set of 1000+ Multiple Choice Questions and Answers.