The **bc command**, short for** basic calculator,** is a language that supports arbitrary precision numbers with interactive execution of statements. Its syntax is similar to that of C programming language. It has two major applications. One as a **mathematical scripting language** and the second as an **interactive mathematical shell. **

In this tutorial, we will learn how to use the bc command for performing mathematical, logical and boolean operations.

## How to use the bc command as an interactive mathematical shell?

To enter the interactive mathematical shell type :

```
bc
```

Press **Enter**.

Now you can start performing mathematical operations.

Let’s try out some :

```
5+5
```

Output :

```
10
```

Let’s try another one :

```
7/3
```

Output :

```
2
```

Here are some other operations :

## How to use the bc command along with the echo command?

You can use the bc command to compute mathematical operations without entering into the interactive mathematical shell. To perform mathematical operations and output the result, you can use the echo command along with bc.

The syntax for doing that is :

```
echo "3+9" | bc
```

Output :

```
12
```

Let’s try another one :

```
echo "3*9" | bc
```

Output :

```
27
```

Here’s another one :

```
echo "3/9" | bc
```

Output :

```
0
```

## How to change the number of digits after the decimal?

You can set the number of digits after the decimal by changing the value of **scale parameter.** The syntax for doing that is:

```
echo 'scale=25;100/23' | bc
```

Output :

```
4.3478260869565217391304347
```

Let’s try another value for scale.

```
echo 'scale=10;100/23' | bc
```

Output :

```
4.3478260869
```

## How to provide input from a file?

You can also provide the input from a file. To do that let’s create a file with multiple lines of mathematical operations in it.

We will use the **cat command** for creating a file.

```
cat > bc_calc.txt
```

The text for the file is as follows:

```
5+7
7*7
20/5
```

To give this file as input to bc command use :

```
bc < bc_calc.txt
```

Output :

```
12
49
4
```

## How to convert from Binary to Decimal?

Bc also lets you convert from one number system to another. To convert from **binary to decimal** you can use :

```
'ibase=2;obase=A;11' | bc
```

Output :

```
3
```

Let’s try another one :

```
'ibase=2;obase=A;111' | bc
```

Output :

```
7
```

## How to convert from Decimal to Binary?

To convert from **Decimal to Binary **you can use :

```
'ibase=10;obase=2;3' | bc
```

Output :

```
11
```

Let’s try another one :

```
'ibase=10;obase=2;7' | bc
```

Output :

```
111
```

## How to declare variables under bc?

Since bc is also a mathematical scripting language you can declare variables for performing mathematical operations. The syntax for doing that is :

```
echo "x=15; x+=10;x" |bc
```

Output :

```
25
```

Let’s try another one :

```
echo "x=15; x*=10;x" |bc
```

Output :

```
150
```

## How to perform boolean operations under bc command?

You can also use the bc command to perform boolean operations.

```
echo "11<=7" | bc
```

Output :

```
0
```

0 is equivalent to false.

Let’s try another one :

```
echo "11>=7" | bc
```

Output :

```
1
```

This is equivalent to true.

## Conclusion

This tutorial was about the bc command in Linux. We learned how to use this command for performing mathematical, logical, and boolean operations. To read more on the bc command, refer to the documentation. Alternatively, you can use the man command to read the manual.