Bash script to use in a cron job in order to receive an email when a web page changes

webpage_modification_notifier.sh

#!/bin/bash
# USAGE: ./webpage_modification_notifier.sh $URL
set -o pipefail -o errexit -o nounset
date

cd $(dirname "${BASH_SOURCE[0]}")

url="${1?'Argument required'}"
echo $url
last_version=${url//[^[:alpha:]]/}.html
tmpfile=$(mktemp /tmp/webpage_modification_notifier.XXXXXX)

curl -sk "$url" | grep -vE 'random|sesskey' > $tmpfile

if ! [ -e "$last_version" ]; then
    mv $tmpfile $last_version
    exit 0
fi

if diff -q $last_version $tmpfile; then
    rm $tmpfile
    exit 0
fi

echo "Web page changed, sending notification"
(echo -e "$url\n\n"; diff $last_version $tmpfile || true) | mail -s "[webpage_modification_notifier] Change detected on $url" [email protected]
mv $tmpfile $last_version