3.1 Getting started

If you’re planning to run this on Fedora container, complete the following section if you plan to work on WSL or directly on your machine skip to the next section and start with Create a sandbox location to facilitate script execution.

Prerequisites for executing the scripts

  • Run a new fedora container

  • Create a new privileged user

# Create a fedora docker container
docker run -it fedora bash

# install utilities (for normal virtual machines we don't need to install them)
dnf install -y util-linux tree passwd vim

# Create a new user and add it to the wheel group to have sudo permissions

useradd <NAME> -G wheel

# setup a password for the user

passwd <NAME>

# Remove the password request for the sudo commands
vim /etc/sudoers

# comment
# Allows people in group wheel to run all commands
%wheel ALL=(ALL)       ALL

# And uncomment
# Same thing without a password
%wheel  ALL=(ALL)       NOPASSWD: ALL

# switch to the newly created user

su <NAME>

Create a sandbox location to facilitate script execution.

# change the directory to user's home
cd

# create a new sandbox
mkdir sandbox

#change the directory to the new directory
cd sandbox

# or run everything in one single command
mkdir ~/sandbox && cd ~/sandbox

# Update bash profile file with the location of the scripts so we can call them directly from everywhere
# Open file using vim

# .bashrc and .bash_profile are 2 files that host all our custom settings for the bash shell
vim ~/.bashrc

# add at the end of the file the line and save
export PATH="$PATH:/home/${USER}/sandbox/scripts"

# sourcing means that you run a file to get some variables out of it
source ~/.bashrc

1. Making your first script

  1. Create a script

  2. Add executable permission

  3. Add content

  4. Run the script

# Create script
touch HelloWorld1

# add executable permission
chmod u+x HelloWorld1

# Edit content
vim HelloWorld1

Add inside the file and then save

# !/usr/bin/env bash
echo "Hell on World"

Run the script using the command

bash HelloWorld1
# or
./HelloWorld1

# or if the script location is in PATH
HelloWorld1

INPUT and OUTPUT

read

touch Input1 && chmod u+x Input1 && vim Input1

# !/usr/bin/env bash
read name
echo "Hello, $name"

Run using

touch Input2 && chmod u+x Input2 && vim Input2

# !/usr/bin/env bash

read -p "Enter your name: " name
echo "Hello, $name"

touch Input3 && chmod u+x Input3 && vim Input3

# !/usr/bin/env bash
echo "Hello, ${1}"

touch Input4 && chmod u+x Input4 && vim Input4

# !/usr/bin/env bash

echo "Total arguments: $#"
echo "Script Name = $0"
echo "First Argument = $1"
echo "Second Argument = $2"