Fast network ping scan in bash (queried)

scan_net.sh

#!/bin/sh
NET=1.1.1.
FROM=2
TO=254
IF=eth1
sSTOP=0

control_c(){
 echo Catch interrupt signal, aborting...
 sSTOP=1
}

ping_a(){
 arping -I $1 $2 -c 1 1>/dev/null 2>&1
 if [ $? -eq 0 ]; then
  echo "${NET}$c" >>/tmp/png
 fi 
}

trap control_c SIGINT
rm -f /tmp/png 1>/dev/null 2>&1

for ((c=$FROM; c <= $TO && $sSTOP == 0; c = c + 1)); do
 ping_a "${IF}" "${NET}$c" &
done

wait

if [ -f /tmp/png ]; then
  cat /tmp/png
else
 echo "No hosts found"
fi