Create a simple calculator which can perform basic arithmetic operations like addition, subtraction, multiplication or division depending upon the user input in Bash.

Example:

Enter two numbers: 5.6 3.4 Enter Choice: 1. Addition 2. Subtraction 3. Multiplication 4. Division 3 5.6 * 3.4 = 19.0

**Approach:**

1. Read Two Numbers 2. Input Choice (1-Addition, 2-Subtraction, 3-Multiplication, 4-Division) 3. if Choice equals 1 Calculate res = a + b else If Choice equals 2 Calculate res = a - b else if Choice equals 3 Calculate res = a * b else if Choice equals 4 Calculate res = a / b 4. Output Result, res

**Commands/Statement Used:****1. echo**

echo is one of the mostly used command.

It is used to print a line of text in standard output.

$ echo [-neE] [arg ...]

**2. read**

The command read in the Linux is used to read the input from the keyboard.

**3. Switch-Case**

When there are a lot of if statement in Shell and it becomes confusing. Then it is good to use case statement.

**4. bc Command**

Checkout the link for bc Command bc Command Linux Example

## Bash

`# !/bin/bash` ` ` `# Take user Input` `echo` `"Enter Two numbers : "` `read` `a` `read` `b` ` ` `# Input type of operation` `echo` `"Enter Choice :"` `echo` `"1. Addition"` `echo` `"2. Subtraction"` `echo` `"3. Multiplication"` `echo` `"4. Division"` `read` `ch` ` ` `# Switch Case to perform` `# calulator operations` `case` `$ch ` `in` ` ` `1)res=`` `echo` `$a + $b | ` `bc` ``` ` ` `;;` ` ` `2)res=`` `echo` `$a - $b | ` `bc` ``` ` ` `;;` ` ` `3)res=`` `echo` `$a \* $b | ` `bc` ``` ` ` `;;` ` ` `4)res=`` `echo` `"scale=2; $a / $b"` `| ` `bc` ``` ` ` `;;` `esac` `echo` `"Result : $res"` |

Output:

**References:**

Array Basics Shell Scripting | Set 2 (Using Loops)

Array Basics in Shell Scripting | Set 1

Sorting an array in Bash using Bubble sort

bc Command Linux Example