Discover Machine info connected to N/W using Nmap Linux tool

#! /bin/bash

ETHERNET=eth0

HostList=(`arp -vni $ETHERNET |cut -d " " -f 1 |grep -r 192 |xargs`)

for (( i = 0 ; i <= ${#HostList[*]} ; i++ ))
    do
    #nmap ${HostList[i]}
    #nmap -O --system-dns ${HostList[i]}
    #nmap -O --osscan-guess --system-dns ${HostList[i]}
    nmap  -F -O -o2 --osscan-limit -oX ${HostList[i]}_$i.xml  ${HostList[i]}
done