UNIX MCQs

By: Prof. Dr. Fazal Rehman | Last updated: May 30, 2025

1. Taking input from standard input, which of the following symbol is used?
(A) &
(B) %
(C) $
(D) –

2. For representing error messages, _____ stream is used:
(A) Standard error
(B) Standard output
(C) Standard input
(D) Error

3. Which of the following command saves one copy of the character stream in the file and stores the other to the standard output?
(A) tee
(B) ls
(C) who
(D) wc

4. The ____ stream is connected to display:
(A) Standard output
(B) Standard input
(C) Standard error
(D) Error

5. To represent standard error stream we use _______ file descriptor:
(A) 0
(B) 1
(C) 3
(D) 2

6. _______ command is used to redirect the error message to a file named errorfile:
7. To represent different standard streams, how many files are used?
(A) 1
(B) 2
(C) 3
(D) 4

8. To redirect the output to a file or another program, which symbol is used?
9. Not true about tee command is _____
(A) tee is an internal command
(B) It is an external command
(C) tee command duplicates its input
(D) It is a feature of the shell

10. In UNIX, which files are called special files?
(A) sample.txt
(B) /dev/null and /dev/tty
(C) /dev/tty
(D) /dev/null

11. To redirect the error messages to /dev/null, which of the following symbol is used?
12. What is the category of the commands called which uses both standard output and standard input?
(A) Directory oriented commands
(B) Standard input commands
(C) Standard output commands
(D) Filters

13. For the interpretive cycle of the shell, in the entered command the shell first scans for ___
(A) Meta-characters
(B) Priority
(C) Characters
(D) Wildcards

14. In the C shell, for command prompt, the default symbol is ____
(A) $
(B) @
(C) #
(D) %

15. What is true about Shell in the following?
(A) Shell is a multi-faceted program
(B) Shell is the command interpreter
(C) To work in, the shell is a multi-faceted, command interpreter and provides us such an environment
(D) To work in, the shell provides us with such an environment

16. What is the prompt called issued by the shell?
(A) Prompt
(B) Command translator
(C) Command executor
(D) Command prompt

17. Which command will display the name of the shell on which we are working?
(A) echo $SHELL
(B) echo $
(C) echo shell
(D) echo $$

18. ___ command is used for changing the login shell in some systems (like Linux):
(A) chsh
(B) chshl
(C) chshell
(D) ch

19. There will be ____ shells simultaneously running on the UNIX system:
(A) Many
(B) 2
(C) 1
(D) 4

20. Until we log out of a system, which command does not terminate?
(A) history
(B) login
(C) echo
(D) shell

21. If we need an expression in which the last character is not numeric, which expression is a correct wildcard pattern?
(A) *[!0-9]
(B) *[0-9]
(C) [0-9]
(D) *[!0]

22. There are __ major types of shells in the UNIX.
(A) 3
(B) 2
(C) 4
(D) Many

23. In the Bourne shell, for command prompt, the default symbol is ____
(A) #
(B) %
(C) $
(D) @

24. The most common and best to use is ______ shell:
(A) Korn
(B) Bash
(C) C
(D) POSIX