A simple URL status checker in Go. Made to practice a bit with channels and goroutines.

checker.go

package main

import (
	"bufio"
	"container/list"
	"flag"
	"fmt"
	"net/http"
	"io"
	"os"
)

var file = flag.String("file", "", "The file to load")

type urlInfo struct {
	Url, Status string
}

func read_file(fn string) *list.List {
	f, err := os.Open(fn)
	if err != nil {
		panic(err)
	}

	l := list.New()

	r := bufio.NewReader(f)
	for {
		line, _, err := r.ReadLine()

		if err == io.EOF {
			break; // end of the file
		}

		if err != nil {
			fmt.Println(err)
			continue
		}

		l.PushBack(string(line))
	}

	return l
}

func fetch_url(url string, ch chan urlInfo) {
	var i = urlInfo{Url: url}
	if resp, err := http.Head(url); err != nil {
		i.Status = "--"
	} else {
		i.Status = resp.Status
	}
	ch <- i
}

func main() {
	flag.Parse()
	l := read_file(*file)

	ch := make(chan urlInfo, l.Len())
	for e := l.Front(); e != nil; e = e.Next() {
		go fetch_url(e.Value.(string), ch)
	}

	var count = 0;

	for {
		u := <- ch
		fmt.Println(u.Url, "\t", u.Status)

		// seems like there's a better way to do this?
		count++
		if count >= l.Len() {
			break;
		}
	}
}