# Binary, octal, and hex arithmetic operations in Linux shell

April 09, 2021

Integer values can be represented in decimal, binary, octal, or hex numeric notations. By default, integer values are represented in decimal notation. Binary numbers have base `2`. Octal numbers use base `8`. Hexadecimal numbers use base `16`. We will learn about various notations with examples in this section.

This is the syntax:

variable=base#number-in-that-base

Let’s understand the preceding syntax with examples:

• Decimal representation:
``````\$ declare -i x=21
\$ echo \$x21``````
• Binary representation:
``````\$ x=2#10101
\$ echo \$x21``````
• Octal representation:
``````\$ declare -i x
\$ x=8#25
\$ echo \$x21``````
``````\$ declare -i x
\$ x=16#15
\$ echo \$x21``````

In the preceding examples, we displayed the decimal `21` value in binary, octal, and hexadecimal representations. ## Creating a config file and using it in tandem with your scripts

In this article, we are going to create a config file and use it in our shell script.PrerequisitesBesides having a terminal open, you need basic knowledge of creating scripts and config files.Write scriptNow, we are going to create a script and config file. The...