Simple script for getting geo information from ip or host name

ipinfo.sh

#!/bin/sh
# Simple script for getting geo information from ip or host name.
# This script uses linux command `host` to get ip address for
# the given domain name. It also depends on `http://ipinfo.io/`
# to get the geo information.
# 
# The valid_ip function has been copied directly from
# http://www.linuxjournal.com/content/validating-ip-address-bash-script
#
# INSTALLATION
#   Save as /usr/local/bin/ipinfo
#   chmod u+x /usr/local/bin/ipinfo
#
# USAGE
#  ipinfo <ip>
#  ipinfo <domain>
#  ipinfo bhoos.com
#  ipinfo 54.230.190.68
#


# Test an IP address for validity:
# Usage:
#      valid_ip IP_ADDRESS
#      if [[ $? -eq 0 ]]; then echo good; else echo bad; fi
#   OR
#      if valid_ip IP_ADDRESS; then echo good; else echo bad; fi
#
function valid_ip()
{
    local  ip=$1
    local  stat=1

    if [[ $ip =~ ^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$ ]]; then
        OIFS=$IFS
        IFS='.'
        ip=($ip)
        IFS=$OIFS
        [[ ${ip[0]} -le 255 && ${ip[1]} -le 255 \
            && ${ip[2]} -le 255 && ${ip[3]} -le 255 ]]
        stat=$?
    fi
    return $stat
}


# Store the argument for using later
ARG=$1

if valid_ip $ARG; then
  curl ipinfo.io/$ARG
else
  IP=$(host $ARG | awk '/has address/ { print $4 ; exit }')
  if [ "" == "$IP" ]; then
    echo "$ARG could not be resolved"
  else
    curl ipinfo.io/$IP
  fi
fi