#Sort text file
sort()
{
	sort $filename.on > $filename.on.done
	sort $filename.off > $filename.off.done
	rm -rf $filename.on
	rm -rf $filename.off
	mv $filename.on.done $filename.on
	mv $filename.off.done $filename.off
	rm -rf $filenameBAK
}


if [ $# -lt 1 ]
then
	#call usage function
	usage
fi

#Variables
filename=$1
filenameBAK="$1BAK"
debug="echo"
#debug=":"


cat $filename |
while read line #read each line of the file into variable line
do   

	#randomize text file 
	#ERROR EHRE~~~
	cat test1 |while read l ; do echo "0$RANDOM $l" ; done|sort -n -o test1.shi
	
	
	#Generate random port
	rand=0
	RANGE=65535 #total ports
	FLOOR=1025 # greater than 1024 (eliminating root ports)
	while [ "$rand" -le $FLOOR ]
	do
		rand=$RANDOM
  	let "rand %= $RANGE"  # Scales $number down within $RANGE.
	done
	$debug "Random number between $FLOOR and $RANGE ---  $rand"
	#end of generate random port


	#Split ip from host name to use it
	oldifs="$IFS"

	$debug "input line is :$line:"
      	IFS="${IFS}=" #IFS BEFORE USING!
	set -- $line #use line splited from ip=dns to ip dns ($1 $2)

        ip=$1
        dns=$2
       	
	$debug "IP: $1"
	$debug "DNS: $dns"
        
	IFS="$oldifs"
	#End of splitting ip and dns

	#Search crafted string and execute command
	#Special
	# -p random number
	# -i time (waittime, 20 secs)
	#-s port (source port)
	#--keep
	#./hping2 -c 1 -A -V  -p $rand -i time
	#Send one packet, ACK, Verborse, at random port, every 20 secs, source port 80
	#./hping2 -c 1 -A -V -p $rand -i 20 -s 80 --keep $ip
	# Find: 1 packets tramitted, 1 packets received, 0% packet loss
	
	status="" #ON/OFF
	#hping output is not the statistics.. its the response
	#ACK returns RST flag
	./hping2 -c 1 -A -V -p $rand -i 20 -s 80 --keep $ip  |grep "flags=R"

	# $? stands for last commands exit status
	# If its 0 then grep was successfull and host is alive :)
	if [ "$?" -eq "0" ]; then
	
		status="ON"
		echo "$status $ip=$dns" >> $filename.on
	else
		status="OFF"
		echo "$status $ip=$dns" >> $filename.off
	fi
	$debug "Status: $status"
	#End of search crafted string

	sort #call sort funtion
	
done