An example of concurrency in Go programming

fetch_concurrently.go

package main 

import (
	"fmt"
	"time"
	"net/http"
)

var urls = []string{
	"http://google.com",
	"http://yahoo.com",
	"http://bing.com",
	"http://youtube.com",
}

func main() {	
	start := time.Now()
	c := make(chan string)
	for _, url := range urls {
		go fetch(url, c)
	}	
	for i := 0; i < len(urls); i++ {
		fmt.Println(<-c)
	}
	
	fmt.Println("Total Time: ", time.Since(start))
}

func fetch(url string, c chan string) {
	start := time.Now()
	resp, err := http.Get(url)	
	if err != nil {
		c <- fmt.Sprintf("Error: %s", err)
		return
	}
		
	c <- fmt.Sprintf( "Url: %s, Time: %s, Status: %s", url, time.Since(start), resp.Status ) 
}