case-thing.sh

#!/bin/bash

function one () {
  echo 'RUN: function 1'
}

function two () {
  echo 'RUN: function 2'
}

function three () {
  echo 'RUN: function 3'
}
DOMAIN=$(hostname -d)
	if [ -z "$DOMAIN" ]
	then 
		echo "ERROR: domain variable is null"
		exit 1
	fi

if [[ $HOSTNAME =~ .*01$ ]]; then HOSTCAT=1; fi
if [[ $HOSTNAME =~ .*02$ ]]; then HOSTCAT=2; fi
if [[ $HOSTNAME =~ .*03$ ]]; then HOSTCAT=3; fi

case $HOSTCAT in 
	1) one;;
	2) two;;
	3) three;;
	*) echo "UNKNOWN CASE" && exit 1
esac