#!/bin/sh

# [4.2.3] cronjob - pingscan and reverse DNS based [nmap]

# This example uses nmap to ping your whole network and take
# a "snapshot" of it. nmap prints the DNS name acquired from
# reverse DNS, if found. Else, nmap just prints the IP. This
# is fine.

NET="172.16.1.0/24"
PREHOSTS="$HOME/.tcsh/hosts-pre"
HOSTS="$HOME/.tcsh/hosts"

(cat $PREHOSTS
 nmap -sP $NET | grep -v -i nmap | awk '{print $2}'
) | sort > $HOSTS