#!/bin/sh

set -e

find_host() {
    zgrep -F "$(host "$1" | cut -d' ' -f4)" "$2" | tail -n1
}

if ! [ "$#" = 1 ]; then
   echo "Invalid argument, use --help or -h for usage information." >&2
   exit 1
fi

hostname=$1 && shift

if [ "$hostname" = "-h" ] || [ "$hostname" = "--help" ]; then
   echo "nmgrep, find the last known information about a hostname"
   echo "Usage: nmgrep <hostname> | --help | -h"
   exit 0
fi

cd /var/log/netmonitor

for logfile in mappings.*; do
    result=$(find_host "$hostname" "$logfile")
    if ! [ -z "$result" ]; then
    	echo "$result"
	exit 0
    fi
done
exit 0