Ajam: exhausting.

main.go

package main
// Ajam: I might be abrasive but at least I make the effort for people. 
// I'm surprised you couldn't be bothered to do the 50 lines yourself 
// after the hour I put in, but I'm a man of my word.
// It did indeed take me about 20 minutes to find. It uses a quotient filter.

import (
   "bufio"
   "flag"
   "fmt"
   "github.com/facebookincubator/go-qfext"
   "github.com/joeguo/tldextract"
   "regexp"
   "strings"
   log "github.com/sirupsen/logrus"
   "os"
)

func init() {
   flag.Parse()
   log.SetLevel(log.DebugLevel)
}

func main() {
   s := bufio.NewScanner(os.Stdin)
   q := qf.New()
   cache := "/tmp/tld.cache"
   extract, _ := tldextract.New(cache, false)
   for _, f := range flag.Args() {
       fi, _ := os.Open(f)
       if fi != nil {
           s  := bufio.NewScanner(fi)
           for s.Scan() {
               q.InsertString(strings.ToLower(strings.TrimSpace(s.Text())))
           }
       }
   }
   log.Infof("%d added to filter", q.Len())
   var t *tldextract.Result
   r := regexp.MustCompile("[a-z0-9\\-_\\.]+")
   for s.Scan() {
       for _, f := range r.FindAllString(s.Text(), -1) {
           t = extract.Extract(f)
           if t != nil {
               dom := fmt.Sprintf("%s.%s", t.Root, t.Tld)
               //log.Debugln(dom, f)
               if q.ContainsString(dom) {
                   fmt.Println(s.Text())
                   break
               }
           }
       }
   }
}