Get external IP and display it to stdout

getip.nim

import httpclient, re

proc subString(s: string, start: int, stop: int): string =
  return s[start..stop]

var resp: string = ""
try:
  resp = getContent("http://checkip.dyndns.org")
except ProtocolError:
  quit("Error")
var start = find(resp, re"(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})")
if start != -1:
  var stop = find(resp, re"<\/body>")
  echo (resp.subString(start, stop-1))
else:
  echo "Unknown"