1. UNIX allows the system administrator to use the only chown to change both owner and group.
2. Which symbol is used to change permissions for hidden files?
3. Shell enables one or more arguments to be obtained from the standard output of another command. This feature is called _________
Correct Answer is : command substitution
4. Which of the following meta-character is used in command substitution?
5. Command substitution is enabled in single quotes also.
Correct Answer is : FALSE
6. POSIX recommends the use of ____ instead of archaic `command ` for command substitution.
7. Which of the following shell doesn’t support the command substitution using $ recommended by POSIX?
Correct Answer is : bourne
8. Which symbol is used for assigning a value to variables?
9. Which symbol is used for evaluation of variables?
10. Which of the following is a correct initialization of variables to null strings?
Correct Answer is : x=, x=’ ‘, x=” “
11. A variable can be removed using _____
Correct Answer is : unset
12. readonly command is used to protect a variable from reassignment.
13. The variable assignment as x = 10 (whitespace on both sides of =) will work if we are not using C shell?
Correct Answer is : FALSE
14. What will the result when we evaluate this statement?
$ directory=’pwd’=`pwd`
Correct Answer is : output of pwd command along with string pwd=
15. Which of the following is not a system defined variable?
16. Which of the following is an invalid variable?
Correct Answer is : -txtfile
17. Command substitution requires the command to use ________
Correct Answer is : standard output
18. The command is valid.
$ ls -lRa $HOME > home.ls
19. What are Commands?
Correct Answer is : specific instructions for performing a particular task
20. In how many categories, commands of UNIX operating system classified?