2) Which of the following Unix command(s) can be used to check if the variable a is equal to the string "exam2" or not? (a) test a = "exam2" (b) [ $a = "exam2" ] (c) [a -e em2"] (d) test 'echo $a grep -cx Sa-e 1 3) The following statements are related to the return value of Unix process. Which one is (are) the true statement(s)? (a) Every Unix process terminates with an exit value (b) The returned value 0 means success for Unix process. (c) All built-in commands return 0 when they fail (d) None of above 4) To inhibit command substitution when echoing a string, we can use (a) Double quotes (b) Grave accent (c) Single quote (d) Curly brace 5) How to obtain the value of command line arguments in a shell program? (a) $0 would be the first line argument, $1 would be the Second command line argument, $2 the Third, and so on (b) S1 would be the first command line argument, $2 the second, and so on $0 is the name of the script or function (c) Both a and b are correct (d) Both a and b are incorrect 6) Which statement below is incorrect for shell? (a) Shell is a command interpreter (b) When a shell is started, it reads and executes a special start up file (c) When a shell is started, it removes all the files in user's home directory (d) The prompt in terminal is displayed by shell