How can I write a Linux bash script that tells me which computers are ON in my LAN?

Question

How can I write a Linux Bash script that tells me which computers are ON in my LAN?

It would help if I could give it a range of IP addresses as input.

Answer 1

#!/bin/bash

for ((n=0 ; n < 30 ; n+=1))
do
    ip=10.1.1.$n
    if ping -c 1 -w 1 $ip > /dev/null 2> /dev/null >> /etc/logping.txt; then  
        echo "${ip} is up" # output up
        # sintax >> /etc/logping.txt log with .txt format
    else
        echo "${ip} is down" # output down
    fi
done