Programming :: Bash Script To Ping A Range Or Own IP-range?

I want to build a bash script, which can ping a range IP adresses which will be filled in by the admin. If there is no IP-adress filled in, then the script must ping the subnet where the system is logged on. So if my ip is 192.168.1.6, then the script must ping from 192.168.1.1 till 192.168.1.255 Or else, if there is given a beginning and ending ip it must ping that!

The first part of the bash script is to ping a given range (see below). But there is one problem, how can I tell the script to ping from $begin till $end, [..] is of course wrong! But what must be filled in there???

echo "Enter beginning IP-adres:"
read begin
echo "Enter ending IP-adres:"
read end
ping -c 1 $begin [..] $end

The second part is to find my own ip and ping the whole range.. How to do that? I only can find my own IP, but I cant ping the whole range,, how to do that?

#!/bin/bash
ifconfig | grep 'inet addr:' | grep -v '127.0.0.1' |
cut -d: -f2 | awk '{ print $1 }'