Simple tool using curl, mailx, and a crontab to monitor whether a site is up or not

mailx_site_monitor.sh

#!/bin/sh

# How many seconds does it usually take your site to respond?
sec=2

# Try to download the site to a file
curl -s -m $sec example.org > /tmp/dltime 
# Get size of file
a=`wc -m /tmp/dltime | awk '{print $1}'`

# If it didn't download, the file will have size of 0
if [ $a -eq 0 ]; then
	# send me a reminder
	echo OH SNAP WE\'VE BEEN SLASHDOTTED \
	| mailx -s "Server responding slowly" email@example.com
fi