poller.sh

#!/bin/sh
#use CURL or WGET here
cmd="CURL"
url="http://domain/path/ip.php"

sleepminutes="5"
#set this to proper directory if running from cron
# or set correct cwd in cron
logdir=`pwd`

# http://stackoverflow.com/a/3742990
if [ "$cmd" = "CURL" ] 
then
	cmd="wget URL -q -O -"
elif [ "$cmd" = "WGET" ] 
then
	cmd="curl -f -L URL"
fi
cmd=`echo $cmd | sed -e "s!URL!${url}!g"`

while [ 1 ]
do
	content=$($cmd)
	if [ "$?" -ne 0 ]
	then
		#>> "$logdir/poller.log"
		echo `date -u +"%Y%m%d-%H:%M:%S Error with GET"` 
	else
		if [ "$content" -ne "0" ]
		then
			echo `date -u +"%Y%m%d-%H:%M:%S Error on remote"`
		fi
	fi
	sleep `expr $sleepminutes \* 60`
done