Class 26

Question 1

If the variable dir_name had the value “hw”, how would you use this variable to create the string “hw10”?

Answer 1

${dir_name}10

Question 2

What is the value stored in the special parameter $ ?

Answer 2

The process ID of the current shell.

Question 3

What is the value stored in the special parameter ! ?

Answer 3

The process ID of the last command sent into the background

Question 4

What is the value stored in the special parameter ? ?

Answer 4

The exit status of the last command run.

Question 5

What is the value stored in the positional parameter 0 ?

Answer 5

The pathname used to run a script

Question 6

What are the values stored in the positional parameters 1 to n ?

Answer 6

The value of the corresponding command line argument

Question 7

What is the value stored in the special parameters * and @ ?

Answer 7

all the command line arguments

Question 8

How are the values of the special parameters set?

Answer 8

they are set by Bash

Question 9

What happens after the following command is run in a script? shift

Answer 9

all positional parameter values are moved to the previous positional parameter

Question 10

What happens after the following command is run in a script? shift 2

Answer 10

all positional parameters values are moved to the positional two steps lower