get a SPF record based on an IP address, if possible

get_spf

#!/usr/bin/env bash
#
# checks if a SPF record is present for a given IP
# if that IP resolves for the MX and is used without
# redirects/load balacing etc.
#
# needs to be improved
#
readonly IP=${1}

function get_pointer() {
  local pointer=$(dig -x "${IP}" +short)
  printf "%s\n" ${pointer%.}
}

function main() {
  local pointer=$(get_pointer)
  [[ -z ${pointer} ]] && return 1
  local txt=$(dig TXT "${pointer}" +short)
  [[ ${txt} =~ "spf" ]] || return 1
  echo ${txt}
}

main
#EOF