How to Use GNU bc (Basic Calculator) in Linux?

GNU bc (Basic Calculator) is a powerful command-line calculator utility in Linux that enables users to perform advanced mathematical calculations, including floating-point arithmetic, complex mathematical functions, and programmable calculations. It supports arbitrary precision arithmetic, making it ideal for both simple calculations and complex mathematical operations.

Installing GNU bc

Most Linux distributions include GNU bc in their default repositories. First, check if bc is already installed on your system

$ bc --version

If bc is not installed, use your distribution's package manager to install it

Ubuntu/Debian-based systems:

$ sudo apt-get install bc

Fedora/CentOS/RHEL systems:

$ sudo dnf install bc

Arch Linux systems:

$ sudo pacman -S bc

After installation, verify bc is working by starting the interactive calculator

$ bc

Basic Arithmetic Operations

GNU bc supports standard arithmetic operations with proper order of operations (PEMDAS). You can use bc interactively or pass expressions directly from the command line.

Interactive Mode Examples

Addition:

$ bc
2 + 3

5

Subtraction:

5 - 3

2

Multiplication:

2 * 3

6

Division:

6 / 3

2

Command Line Usage

You can also perform calculations directly from the command line using echo and pipes

$ echo "2 + 3" | bc

5

Advanced Mathematical Operations

GNU bc supports advanced mathematical functions and operations for scientific calculations.

Exponentiation and Modulus

Exponentiation (power):

2^3

8

Modulus (remainder):

10 % 3

1

Mathematical Functions

For advanced functions, you need to load the math library using the -l option

$ bc -l

Square root:

sqrt(25)

5

Natural logarithm:

l(10)

2.30258509299404568401

Sine function (radians):

s(1.5708)

1.00000000000000000000

Setting Precision and Scale

GNU bc allows you to control the precision of calculations using the scale variable

$ bc
scale=2
10/3

3.33

scale=5
10/3

3.33333

Variables and Programming Features

GNU bc supports variables, functions, and control structures for complex calculations

$ bc
x = 5
y = 3
x * y + 2

17

Useful Command Options

Conclusion

GNU bc is a versatile command-line calculator that provides both basic and advanced mathematical capabilities in Linux. With support for arbitrary precision arithmetic, mathematical functions, variables, and programming constructs, bc serves as an excellent tool for quick calculations and complex mathematical operations in shell scripts and interactive use.