search.pl

#!/usr/bin/env perl -w

sub foo() {
  $pw = `pwgen -ABn 4 1`;
  ($a, $b, $c, $d) = unpack('cccc', $pw);

  $dom[0] = pack('cccc', $a, $b, $c, $d) .'.com';
  $dom[1] = pack('cccc', $b, $a, $c, $d) .'.com';
  $dom[2] = pack('cccc', $a, $c, $b, $d) .'.com';
  $dom[3] = pack('cccc', $a, $b, $d, $c) .'.com';

  if ( system("grep $dom[0] bar > /dev/null") ) {
    system("echo $dom[0] >> bar");
    foreach $dom (@dom) {
      if ( system("! host -vt ns $dom a.gtld-servers.net | grep ^$dom > /dev/null") ) {
        return;
      }
    }
    system("echo $dom[0] | tee -a baz");
  }
}

system("touch bar");
for ($i = 0; $i < 256; $i++) {
  foo();
}