#! /bin/sh
#
# usage: my-global-ipv4-addr [URL]
#
# if URL is provided then fetch and parse it for IPv4 addrs
# else try all known urls
#
if test $# = 1; then
  has() { type "$1" 1>/dev/null 2>/dev/null; }
  parse() {
    sed -n 's/.*\(\(1\?[0-9][0-9]\|2[0-5][0-9]\)\.\(1\?[0-9][0-9]\|2[0-5][0-9]\)\.\(1\?[0-9][0-9]\|2[0-5][0-9]\)\.\(1\?[0-9][0-9]\|2[0-5][0-9]\)\).*/\1/p' |
      grep .
  }
  get () {
    # TODO get random valid user agent
    if has curl; then
      curl -m 1 -A Mozilla -sS "$1" 2>/dev/null
    elif has wget; then
      wget -T 1 -U Mozilla -O "$1" 2>/dev/null
    else
      echo 'Error 1: You are made of stupid!' >&2
      exit 23
    fi
  }

  #addrs="`get "$1" | parse`"
  #echo "$1:" $addrs >&2
  #echo "$addrs"
  get "$1" | parse
else

  vote() {
    sort | uniq -c | sort -r -n
  }
  winner() {
    head -n 1 | awk '{print$2}'
  }
  
  grep -v ^# |
  sed -n '1,$p' |
  xargs -P 42 -n 1 "$0" | vote | winner
fi<<EOF
checkip.dyndns.com
www.whatismyip.de
www.eigene-ip.de
whatismyip.org
www.ipaddressworld.com
http://ip-check.info/?lang=de
http://www.ip-adress.com/what_is_my_ip/
http://www.spyber.com/
http://www.ipchicken.com/
EOF