#!/bin/sh

down=0
result=''

#
# Loop while there are command line arguments avaliable, 
# that is $1, $2, $3, etc... $* starts at $1, $0 is the
# script name itself
#
for host in $*
do
        # Ping, wait up to 5 seconds for a return, only
        # send 1 ping, host is created from command line,
        # and redirect the standard output in to /dev/null
        # and redirect standard error into standard output.
	ping -W5 -c1 $host >/dev/null 2>&1

        # $? is the exit status from the last command 
        # executed, or 'ping' in this case.
        #
        # So, if exit code was not zero (success), then...
	if [ $? != 0 ]; then
		down=`expr $down + 1`
		result="$result $host"
	fi
done

# Remember to concatenate $result so that if more than one
# host is down they'll end up in the result string.
result="$result"

# So, if $down is greater than 2 we have "plural" hosts down.
if [ $down -ge 2 ]; then
	echo "Return code: $down. $result are down." 
# Exit the script with '2'. Not 3, 4, etc... as Nagios does
# not know what this means. 2 means 'failure' and sets the
# service status to 'critical'.
	exit 2	
elif [ $down = 1 ]; then
# Only one host down, error message is singular and we exit
# to Nagios with '1', which results in a warning state.
	echo "Return code: $down $result is down."
	exit 1
else
echo "Return code: $down. All hosts are up."  
exit 0	
fi