Nmap results enhancement + nmap limitations

Now nmap is limited with a --max-rate set to 15 packets per seconds (
when scanning 4 range with the default value the networks begin to
collapse...)
And now nmap is run in background, allowing CIDR scanning processes
to regulary check the nmap result and add new ping processes.

ping_radar.sh

@@ -32,7 +32,7 @@ clean_exit() {
 	for pid in $(echo $pids)
 	do
 		echo killing $pid
-		kill $pid
+		kill $pid 2>/dev/null
 	done
 	for pid in $(echo $pids)
 	do
@@ -44,16 +44,22 @@ clean_exit() {
 	exit 0
 }
 
+cidr_nmap_pid=""
+cidr_nmap_res=""
 cidr_pids=""
 clean_cidr() {
 	echo "CIDR killed, cleaning..."
-	for pid in $(echo $cidr_pids)
+
+	kill $cidr_nmap_pid 2>/dev/null
+
+	for pid in $(echo $cidr_pids $cidr_nmap_pid)
 	do
 		echo CIDR killing $pid
-		kill $pid
+		kill $pid 2>/dev/null
 		wait $pid
 		echo CIDR $pid killed
 	done
+	rm -v $cidr_nmap_res
 	exit 0
 }
 
@@ -116,15 +122,31 @@ cidr_scan() {
 	# $4 delay
 
 	test -z "$4" && delay=5 || delay=$4
+	cidr_nmap_res=$(mktemp -t ping_radar_cidr_nmap.XXXXXXXX)
+	nmap_cmd="nmap -sP -oG $cidr_nmap_res --max-rate=15 $1"
 
 	trap clean_cidr 15
+
+	#nmap -sP -oG "$cidr_nmap_res" $1 >/dev/null &
+	$nmap_cmd >/dev/null &
+	cidr_nmap_pid=$!
+
 	while [ 1 ]
 	do
-		semlock $lock
-		echo "CIDR scanning $1" >&2
-		semrelease $lock
-
-		for h in $(nmap -sP -oG - $1 | grep "Up$" | cut -d " " -f 2)
+		if kill -0 $cidr_nmap_pid 2> /dev/null
+		then
+			semlock $lock
+			echo "CIDR scanning $1" >&2
+			semrelease $lock
+			rerun=0
+		else
+			semlock $lock
+			echo "CIDR scanned $1" >&2
+			semrelease $lock
+			rerun=1
+		fi
+		
+		for h in $(cat $cidr_nmap_res | grep "Up$" | cut -d " " -f 2)
 		do
 			rehost=$(echo $h|sed 's/\./\\./g')
 			if grep " $rehost " $2 > /dev/null
@@ -142,11 +164,12 @@ cidr_scan() {
 			fi
 		done
 
-		semlock $lock
-		echo "CIDR scanned $1" >&2
-		semrelease $lock
-
 		sleep $delay
+		if [ $rerun -eq 1 ]
+		then
+			$nmap_cmd >/dev/null &
+			cidr_nmap_pid=$!
+		fi
 	done
 }