#!/bin/sh
HOSTS_FILES="$HOME/.hosts_scanner"
#HOSTS_FILES="/tmp/hosts"
verbose=0
res_file=$(mktemp -t hosts_scanner.XXXXXXXXXX)
pids=""
date_cmd="date --rfc-3339=s"

lock="${res_file}.lock"

clean_exit() {
	echo "Ctrl+C pressed, exiting..."
	for pid in $(echo $pids)
	do
		kill $pid
		echo $pid killed
	done
	rmdir ${res_file}.lock 2>/dev/null
	rm -v $res_file
	exit 0
}

semlock() {
	while [ 1 ]
	do
		mkdir $1 2>/dev/null && break
	done
}

semrelease() {
	rmdir $1
}

trap clean_exit 2

upd_ping() {
	# update ping stat file
	# $1 host
	# $2 file
	# $3 lock
	lock="$3"
	last_up="never"
	
	while [ 1 ]
	do
		rep=$(ping -qc 1 $1 2>/dev/null  )
		ret=$?
		rep=$(echo $rep | sed -nE 's/.*rtt min\/avg\/max\/mdev = [0-9]+\.[0-9]+\/([0-9]+\.[0-9]+)\/.*$/\1/p')
		rehost=$(echo $h|sed 's/\./\\./g')

		semlock $lock


		if [ $ret -eq 0 ]
		then
			last_up=$($date_cmd)
			#echo "${res}$rep $hstr $last_up" >> $2
		else
			rep="down"
			#echo "${res}down $hstr $last_up" >> $2
		fi

		sed -i "s/^\\s*$rehost\\s.*$/$(printf "%30s %8s %30s\n" $1 $rep "$last_up")/" "$2"

		semrelease $lock

		sleep 5
	done
}

for h in $(cat "$HOSTS_FILES")
do
	printf "%30s %8s %30s\n" $h "unknw" "unknwn" >> $res_file
done

for h in $(cat "$HOSTS_FILES" )
do
	upd_ping $h $res_file $lock &
	pid=$!
	pids="${pids}\n$pid"
	echo "$h updated by $pid" >&2
done
sleep 1

while [ 1 ]
do
	semlock $lock
	clear
	echo "Ping radar $($date_cmd)\n"
	printf "%30s %8s %30s\n" "host" "ping" "last up"
	for i in $(seq 70); do echo -n "="; done
	echo ""

	#cat $res_file

	#grep -v " down " $res_file
	#grep " down " $res_file

	sed -E -e "s/\snever$/$(tput sgr0)\0/" -e "s/^.* down .*$/$(tput setaf 1)\0$(tput sgr0)/"  $res_file

	semrelease $lock
	sleep 1
done