[Online tester] Test if online. A nice guitar pluck sound loud when comes back

testInternet.sh

#!/bin/bash

set -euo pipefail       # unofficial bash strict mode: http://redsymbol.net/articles/unofficial-bash-strict-mode/
IFS=$'\n\t'

# By Pablo Bianchi (pablo.bianchi@gmail.com)
# Infinit loop testing if we are onliene. When we are start beeping.
# (based on http://www.linuxscrew.com/2009/04/02/tiny-bash-scripts-check-internet-connection-availability/ )
#~ USAGE: Just: ./testInternet.sh
#~ NOTES
#~ Consider http_proxy and https_proxy already setted up
hash play 2>&- || { echo >&2 "I require «play» but it's not installed. Try apt-get install sox. Aborting."; exit 1; }
#~ ToDo:
	#~ LOG, example: /bin/echo $(/bin/date +%Y-%m-%d) $(/usr/bin/uptime)
	#~ take a look to http://www.linuxito.com.ar/gnu-linux-2/nivel-medio/164-script-para-monitorear-un-enlace
	#~ take a look to: wget con  --load-cookies file
	#~ use alternative nm-online o httping

#~ OPTIONS
WGET="`which wget`"
URL="https://www.google.com.ar/"
# URL="http://www.mercadolibre.com.ar/"
TIMEOUT=6
if [ $# -eq 0 ]; then
	delay=3;
else
	delay="$1";
fi
noConnectionMessage="No connection, trying again in $delay seconds...";
connectionMessage="WE HAVE INTERNET! :) Trying again in $delay seconds...";

echo "INTERNET TESTER: Type Ctrl+C to quit";
echo
rm --force /tmp/index.site

function playSound {
	time=1;	# Time played
	if [ `sox --version| grep -oP "v[0-9.]+" | sed "s/[v.]//g"` -lt 1431 ]; then	#analize sox version, if greater than v14.3.1 can use pluck
		play -q -n synth $time sine;
	else
		play -q -n synth $time pluck $1;
		#for i in G4 G4 G4 E4;do play -n synth 0.1 pluck $i repeat 2;done	# You can play with something like this also :) (first three notes from Beethoven 5th symphony)
	fi
}

while [ 1 -eq 1 ]; do
	# $WGET -q --tries=10 --timeout=2 $URL -O /tmp/index.site &> /dev/null || echo "Warning: wget return status code $?"
	$WGET -q --tries=10 --timeout=$TIMEOUT $URL -O /tmp/index.site &> /dev/null || echo -e "wget status code $?."
	if [ ! -s /tmp/index.site ];then
		echo $noConnectionMessage;
		#playSound E2
		sleep 1;
	else
		#~ zenity --warning --text "ADDRESS is back" # Also could use xmessage
		# notify-send -i "notification-network-wireless-full" "Connection state:" "$connectionMessage";
		notify-send -u critical "Connection state:" "$connectionMessage";
		echo $connectionMessage;
		playSound E3
	fi
	sleep $delay;
done

exit 0;

#~ Possible not-obvious reasons for not having connection:
#~ - Invalid MTU: Try ping -s 1500 -c1 yahoo.com lowing from 1500 to what start working. http://swik.net/Ubuntu/Only+Ubuntu/How+to+Optimize+your+Internet+Connection+using+MTU+and+RWIN/cbnda
#~ - DNSs problems: Try flushing DNSs, using Google or OpenDNS servers
#~ 	Ubuntu 11.10 and above doesnt cache names. To investigate: dig -t a ns1.myhostingcompany.com @domain_registrar_dns_server
#~ If you wanted to refresh your settings you could disable and then enable networking or run: sudo service network-manager restart


#~ `which wget`-q --tries=10 --timeout=2 http://www.google.com -O /tmp/index.site &> /dev/null
#~ if [ ! -s /tmp/index.site ];then echo -e "$(date +%F\ %T)\tOFFLINE";  else echo -e "`date '+%Y%m%d'`\tONLINE"; fi

#~ echo "$(date +%F\ %T) - Failed check - $ERROR" &>> $LOG

#~ Resatarting service if offline
	#~ Red Hat/Fedora/CentOS: service network restart
	#~ Debian/Ubuntu: service networking restart


# de http://forums.opensuse.org/archives/sf-archives/archives-programming-scripting/345669-check-internet-connection-script.html
	#if ping -c 3 some.router.at.isp.com
	#then
	#	echo 'Have connectivity'
	#fi

#~ Pinging default gateway: ping -q -w 1 -c 1 `ip r | grep default | cut -d ' ' -f 3` > /dev/null && echo ok || echo error

#~ SIMPLER
#~ #!/bin/bash
#~ wget -q --tries=10 --timeout=20 http://google.com
#~ if [[ $? -eq 0 ]]; then
		#~ echo "Online"
#~ else
		#~ echo "Offline"
#~ fi

This is the list of exit codes for wget:

0       No problems occurred
1       Generic error code
2       Parse error — for instance, when parsing command-line options, the .wgetrc or .netrc…
3       File I/O error
4       Network failure
5       SSL verification failure
6       Username/password authentication failure
7       Protocol errors
8 Server issued an error response