added code related to channels and go routines

main.go

@@ -2,27 +2,41 @@ package main
 
 import (
 	"fmt"
-	"io"
 	"net/http"
-	"os"
+	"time"
 )
 
-type logWriter struct{}
-
 func main() {
-	resp, err := http.Get("http://google.com")
-	if err != nil {
-		fmt.Println("Error:", err)
-		os.Exit(1)
+	links := []string{
+		"http://google.com",
+		"http://facebook.com",
+		"http://stackoverflow.com",
+		"http://golang.org",
+		"http://amazon.com",
 	}
 
-	lw := logWriter{}
+	c := make(chan string)
+
+	for _, link := range links {
+		go checkLink(link, c)
+	}
 
-	io.Copy(lw, resp.Body)
+	for l := range c {
+		go func(link string) {
+			time.Sleep(5 * time.Second)
+			checkLink(link, c)
+		}(l)
+	}
 }
 
-func (logWriter) Write(bs []byte) (int, error) {
-	fmt.Println(string(bs))
-	fmt.Println("Just wrote this many bytes:", len(bs))
-	return len(bs), nil
+func checkLink(link string, c chan string) {
+	_, err := http.Get(link)
+	if err != nil {
+		fmt.Println(link, "might be down!")
+		c <- link
+		return
+	}
+
+	fmt.Println(link, "is up!")
+	c <- link
 }