Goroutine & channel simple example

channel.go

// I read some needlessly confusing explanations of channels when I was
// learning go, so I figured I'd post a very straightforward example and
// describe it to death with comments
//
// If anyone ever stumbles across it, I hope it helps :)
package main

import (
	"fmt"
	"time"
)

func main() {
	// You need a channel first
	c := make(chan string)
	// pass it to some goroutines, let's uses one that ostensibly checks URLs
	go check("google.com", c)
	go check("microsoft.com", c)
	// and another to show whatever output the first two generate
	go showResults(c)
	// The goroutines trigger and execution immediately proceeds, and this
	// app isn't doing anything else, so let's block execution here and let
	// the goroutines run a few times
	time.Sleep(time.Second * 10)
}

// check 'checks' a URL (but doesn't really, for brevity)
func check(url string, c chan string) {
	// it loops forever...
	for {
		// sends a string to the channel
		c <- fmt.Sprintf("%s %s", url, "OK")
		// then sleeps for a second
		time.Sleep(time.Second * 1)
	}
}

// showResults is going to show us our output
func showResults(c chan string) {
	// it loops forever...
	for {
		// and prints whatever gets sent to the channel as it comes in
		fmt.Println(<-c)
	}
}