Bash scripting & cheatsheet

I’ll present you with a curated list of the most handy things to know for Bash scripting. These are some of the most useful components, but they aren’t easy to remember for everyone. Next time your mind is blanking when writing a Bash script, take a look at the Bash scripting cheat sheet below for some quick help.

Bash Scripting Basics:

Here are some of the most basic things to know about Bash scripting. If you are not sure where to start, this would be a good choice.

Conditional statements

Conditional statements with if or case allow for us to check if a certain condition is true or not. Depending on the answer, the script can proceed different ways.

For case statements it is best to just see a basic example:

For case statements it is best to just see a basic example:

#!/bin/bash

day=$(date +"%a")
case $day in 
  Mon | Tue | Wed | Thu | Fri)
    echo "today is a weekday"
    ;;
  Sat | Sun) 
    echo "today is the weekend"
    ;;
  *)
    echo "date not recognized"
    ;; 
esac

Basic if example script:

#!/bin/bash
if [ $1 -eq $2 ]; then
    echo "they are equal"
else
    echo "they are NOT equal"
fi

Bash Loops

Bash loops allow the script to continue executing a set of instructions as long as a condition continues to evaluate to true.

Read User Input

Prompt the user for information to enter by using read command:

#!/bin/bash

read -p "What is your name? " name
echo "Enjoy this tutorial, $name"

Parse input given as arguments to the Bash script:

#!/bin/bash

if [ $# -ne 2 ]; then
	echo "wrong number of arguments entered. please enter two."
	exit 1
fi
echo You have entered $1 and $2.