get IP numbers of instances in an AWS auto scaling group

asg-instances-ips.sh

#!/bin/bash
display_usage() {
  echo -e "\nUsage (default region is us-west-2):\n\n    $0 <auto-scaling-group-name> [<region>] \n"
  }

if [  $# -lt 1 ]
then
    display_usage
    exit 1
fi

for i in `aws --region ${2-us-west-2} autoscaling describe-auto-scaling-groups --auto-scaling-group-name $1 | grep -i instanceid  | awk '{ print $2}' | cut -d',' -f1| sed -e 's/"//g'`
do
aws --region ${2-us-west-2} ec2 describe-instances --instance-ids $i | grep -i PrivateIpAddress | awk '{ print $2 }' | head -1 | cut -d"," -f1
done;