Demonstrating What does set -e mean? Simple: Run each file with your internet connection turned on/off and spot the difference.

example-with-set-e.sh

#!/bin/bash
set -e

wget -O /tmp/example.html example.com; cat /tmp/example.html | wc > /tmp/wordcount.txt

echo "Hello! If we got this far, eveything was a sucess hooraryy!"

example-without-set-e.sh

#!/bin/bash

# If wget fails in this script, the pipe to wc will continue regardless
# This might be bad and not what we want.

wget -O /tmp/example.html example.com; cat /tmp/example.html | wc > /tmp/wordcount.txt

echo "Hello! If we got this far, eveything was a sucess hooraryy!"