Monitors a web page and sends a Pushover notification if it changes.

monitor.sh

#!/bin/bash

# monitor.sh - Monitors a web page for changes
# sends a Pushover notification if it changes

if [[ $# -ne 3 ]]; then
    echo "Usage: $0 <url> <token> <user>" >&2
    exit 2
fi

URL=$1
TOKEN=$2
USER=$3

for (( ; ; )); do
    mv new.html old.html 2> /dev/null
    curl $URL -L --compressed -s > new.html
    DIFF_OUTPUT="$(diff new.html old.html)"
    if [[ "0" != "${#DIFF_OUTPUT}" ]]; then
        curl "https://api.pushover.net/1/messages.json" -X POST -d "token=$TOKEN&user=$USER&message=$URL"
        echo "It changed!"
    else
        echo "It didn't change!"
    fi
    sleep 60
done