#! /bin/sh
#------------------- Super Ping : sping ---------------------------
# File:         sping
# Purpose:      ping a full sub-net (netmask 255.255.255.0)
# Date:         07.09.2003
# Author:       Michel Bisson
# Syntax:       sping 192.168.70.  (the last number is omitted!)
#------------------------------------------------------------------
# Declare error function using the Variable $errortext:
# Displays error message and exits with error code 1
error () {
	echo "$errortext"
	echo "Syntax: eg. $0 192.168.70. "
	exit 1
}

# --------Check the validity of the given parameter (Partial IP)
# Only one parameter
if [ "$#" -ne 1 ] ; then
	errortext="ERROR: Incorrect number of parameters."
	error
fi

# ----------Parameter is a correct Partial IP? Correct it if possible
# Accept if xxx.yyy.zzz. or xxx.yyy.zzz 
if ! (echo $1 | egrep "[0-9]*\.[0-9]*\.[0-9]*\.?$" &>/dev/null) ; then 
	errortext="ERROR: Bad subnet Partial IP Syntax"
	error
fi 

# Verify validity if all numbers in IP (0-255)
IFS="."
len=0
for num in $1 ; do
	let "len+=1"
	if [ "$num" -gt 255 ] ; then 
		errortext="ERROR: Wrong values in partial IP Syntax."
		error
	fi 
	if [ "$num" = "" -a "$len" -le 3 ] ; then
		errortext="ERROR: Wrong format of partial network IP."
		error
	fi
done
IFS=" "

# Is IP long enough?
if [ "$len" -le 2 ] ; then
	errortext="ERROR: Wrong number of items in partial network IP."
	error
fi

# Check if subnet IP is valid for local machine in network
if ! (ifconfig | grep "inet " | grep $1 &>/dev/null) ; then
		errortext="ERROR: Partial Subnet IP is not in our local subnet"
		error
fi

# Correct by adding a '.' if missing at the end
if (echo $1 | egrep "\.$" &>/dev/null) ; then
	netip="$1"
else
	netip="$1."
fi
#echo $netip

#-------- Generate all the IPs from xx.xx.xx.1 to xx.xx.xx.254--
netnum=1

#------- Create or Empty the temporary file ---------
echo > /tmp/sping

#------- ping them all almost at the same time (sent as separate jobs)
until [ $netnum -eq 255  ]; do
    /bin/ping -w3 -c1 $netip$netnum 1>>/tmp/sping &
    let "netnum+=1"
done

#----------- wait a bit to let some answers back ----------
sleep 4

#----------- Kill all the ping that are still waiting ---
killall ping &> /dev/null

#----------- Show only the pings that received an answer --
grep '64 bytes from' /tmp/sping | cut -d: -f1 | cut -d" " -f4 | \
								sort -t. -k4n | tee /tmp/nethosts
exit 0