2.2 Basic Bash Syntax

Question 1

How do you start a bash script?

Answer 1

! /bin/bash

Question 2

How do you comment in a bash script?

Answer 2

comment

Question 3

When you create a bash script what do you need to do before it can be executable?

Answer 3

Change the file permissions to allow execution.

Question 4

How do you write a multi-line comment with shell scripting?

Answer 4

Multiple single-line comments, as there is no direct way to create multi-line comments in bash.

Question 5

What is the syntax for creating a variable in bash?

Answer 5

variable_name=value

Question 6

How do you call/use a variable?

Answer 6

$variable_name

Question 7

How do you add a variable to a string?

Answer 7

e.g., echo "text ${variable_name}"

Question 8

What are the types of variables in bash?

Answer 8

User-defined and environment variables (e.g., HOME, USER, etc.).

Question 9

How do you collect input from a user in bash?

Answer 9

read variable_name

Question 10

How do you collect input from a user with a prompt?

Answer 10

read -p ‘message’ variable_name

Question 11

How do you hide user input as they enter it?

Answer 11

read -sp ‘message’ variable_name

Question 12

How is arithmetic done in bash?

Answer 12

• Addition: Use expr $a + $b to add two numbers.
• Subtraction: Use expr $a - $b to subtract the second number from the first.
• Multiplication: Use expr $a * $b to multiply two numbers (escape * with a backslash).
• Division: Use expr $a / $b to divide the first number by the second.