#!/usr/bin/perl

#
# Script to do DNS lookup on a text file
# will look up the first ip address it finds in each line
# (c) Kim Holburn ANU 2004
# released under gpl http://www.gnu.org/copyleft/gpl.html
#

sub fail_usage {
  if (scalar @_) {
    print "  \n";
    print "$0: error: \n";
    map { print "   $_\n"; } @_
  }
  print "  \n";
  print "$0: Usage: \n";
  print "  $0 [options] < file\n";
  print "  options: -d (-b)|-n|-i|-1 \n";
  print "    -n (domain names only) \n";
  print "    -i (ip numbers only) \n";
  print "    -1 (both but only print one) \n";
  print "    -b (both (default)) \n";
  print "    -h|--help (this screen) \n";
  print "  \n";
  exit (scalar @_) ;
}

$opt="";
$debug=0;

while ($ARGV=$ARGV[0]) {
#  if ($ARGV eq '-m') {
#    shift @ARGV;
#    if (!($ARGV = $ARGV[0])) { fail_usage ("-m needs an argument"); }
#    if ($ARGV =~ /^-/) { fail_usage ("-m must be followed by an argument"); }
#    $opt_m = $ARGV;
#  }
  if ($ARGV eq '-n' ) {
    if ($opt) { fail_usage ("only one of options (bni1) permitted"); } 
    $opt = 'n';
  } elsif ($ARGV eq '-i' ) {
    if ($opt) { fail_usage ("only one of options (bni1) permitted"); } 
    $opt = 'i';
  } elsif ($ARGV eq '-1' ) {
    if ($opt) { fail_usage ("only one of options (bni1) permitted"); } 
    $opt = '1';
  } elsif ($ARGV eq '-b' ) {
    if ($opt) { fail_usage ("only one of options (bni1) permitted"); } 
    $opt = 'b';
  } elsif ($ARGV eq '-d' ) {
    $debug++ ; 
  } elsif ($ARGV eq '-h' || $ARGV eq '--help' ) {
    fail_usage();
  } elsif ($ARGV =~ /^-/ ) {
    fail_usage " invalid option ($ARGV)"; 
  } else {
    last ;
  }
  shift @ARGV;
}

if ($debug) { print "args were : "; }
if (!$opt) { $opt = 'b'; }
if ($debug) { print " opt=($opt) debug=($debug)"; }
if ($debug) { print "\n"; }
if ($debug) { print "additional arguments were: ", join (':', @ARGV), "\n"; }

use Socket;

while (<>) {
  if (!/\./) { print "skipped\n"; next; }
#  print "debug opt=($opt)\n";
  if (($opt ne 'n') && (/([^.a-z0-9-]|^)([a-z][a-z0-9-.]*\.([a-z][a-z]|com|edu|org|gov|mil|net|biz|info|name|museum|coop|aero|pro))([^\.a-z0-9-]|$)/i)) {
    $ip="";
    if ($debug) {  print "debug looking up \"$2\" \n"; }
    $addr = gethostbyname($2);
    if (length ($addr) == 4) {
      $ip = inet_ntoa ($addr);
      if ($ip ne "" ) { 
        if ($opt eq 'i'||$opt eq '1') { s/$2/$ip/; }
      }
    }
    if ($opt eq 'b') {
      my $old=$2;
      if ($ip eq "") { $ip = "not found"; }
      s/$old/$old\[$ip\]/;
    }
 #   print "$addr\n";
  } 
  elsif (($opt ne 'i') && /([^\.0-9]|^)([0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3})([^\.0-9]|$)/) {
    if ($debug) {  print "debug looking up \"$2\" \n"; }
    $addr = inet_aton($2);
    $name = gethostbyaddr($addr,AF_INET);
    if ($name ne "") {
      if ($opt eq 'd'||$opt eq '1') { s/$2/$name/; }
    }
    if ($opt eq 'b') {
      my $old=$2;
      if ($name eq "") { $name = "not found"; }
      s/$old/$name\[$old\]/;
    }
  } else { if ($debug) { print "nothing done\n"; } }
  print ;
}