01_hello.bash

#!/usr/bin/env bash

# The first line is called [shebang](http://en.wikipedia.org/wiki/Shebang_%28Unix%29)
# That line in any script determines the script's ability to be executed like a standalone executable without typing sh, bash, python, php etc beforehand in the terminal.

# Use echo to print a string
# Use $ to print a variable
echo "Hello, world! It's $(whoami) on $(hostname)!"

# Using `man` command to view a system’s reference manuals (man pages)
# https://www.educative.io/edpresso/what-is-the-man-command-in-linux

### Challenge
echo "Hello, world!"