In Bash, the `let`

command is used to evaluate arithmetic expressions and assign the result to a variable. It provides a way to perform arithmetic calculations in a concise manner. Here’s the basic syntax of the `let`

command:

```
let <variable> <operator> <expression>
```

The `<variable>`

represents the name of the variable that will store the result of the expression. `<operator>`

is an arithmetic operator such as `+`

, `-`

, `*`

, `/`

, `%`

, etc. `<expression>`

is the arithmetic expression to be evaluated.

Here’s an example that demonstrates the usage of the `let`

command:

```
#!/bin/bash
let "result = 2 + 3"
echo "Result: $result"
let "a = 5"
let "b = 2"
let "c = a * b"
echo "c: $c"
```

In this example, the `let`

command is used to evaluate arithmetic expressions and assign the results to variables. The first `let`

command calculates the sum of 2 and 3 and stores it in the `result`

variable. The second `let`

command assigns the value 5 to the variable `a`

, the value 2 to the variable `b`

, and then multiplies `a`

and `b`

, storing the result in the `c`

variable.

When you run this script, it will output:

```
Result: 5
c: 10
```

The `let`

command is a convenient way to perform arithmetic calculations and assign the results to variables within Bash scripts. It allows you to evaluate complex arithmetic expressions and store the outcomes for further use.