A simple bash script to find the IP addresses of any Raspberry Pi's on the network

findPis.sh

#!/bin/bash
# Copyright Ben Jefferson 2020
# License: GPLv3 https://www.gnu.org/licenses/gpl-3.0.html

# A simple bash script to find the IP addresses of any Raspberry Pi's on the network
if [[ $EUID -ne 0 ]]; then
   echo "This script must be run as root e.g. sudo $0" 1>&2
   exit 1
fi

if [ "$#" -ne 1 ]; then
    echo "Syntax: $0 <Base IP Address>"
    echo "Example: $0 172.16.0.0"
    exit
fi

# Ping-scan the network to make sure all the local IP's are in the ARP table
nmap -T5 -n -p 22 --open --min-parallelism 200 $1/24 > /dev/null

# The list of mac addess prefixes can be found by going here...
# http://standards-oui.ieee.org/oui.txt
# ... and searching for "Raspberry"
ip n | egrep "b8:27:eb|dc:a6:32|e4:5f:01" | grep -Eo '[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}'