Golang: remote filesize with progress bar demo

golearn/remote_filesize/remote_filesize.go

@@ -0,0 +1,53 @@
+package main
+
+import (
+	"fmt"
+	"net/http"
+	"os"
+	"strconv"
+	"strings"
+	"time"
+
+	pb "gopkg.in/cheggaaa/pb.v1"
+)
+
+func main() {
+	url := "https://repo.voidlinux.eu/live/current/void-live-x86_64-20170220-lxde.iso"
+
+	// we are interested in getting the file or object name
+	// so take the last item from the slice
+	subStringsSlice := strings.Split(url, "/")
+	fileName := subStringsSlice[len(subStringsSlice)-1]
+
+	resp, err := http.Head(url)
+	if err != nil {
+		fmt.Println(err)
+		os.Exit(1)
+	}
+
+	// Is our request ok?
+
+	if resp.StatusCode != http.StatusOK {
+		fmt.Println(resp.Status)
+		os.Exit(1)
+		// exit if not ok
+	}
+
+	// the Header "Content-Length" will let us know
+	// the total file size to download
+	size, _ := strconv.Atoi(resp.Header.Get("Content-Length"))
+	downloadSize := int(size)
+	bytesTokilobytes := downloadSize / 1024 / 1024
+
+	fmt.Println("Will be downloading ", fileName, " of ", bytesTokilobytes, " MegaBytes.")
+
+	count := bytesTokilobytes
+	bar := pb.StartNew(count)
+	for i := 0; i < count; i++ {
+		bar.Increment()
+		bar.ShowTimeLeft = true
+		time.Sleep(time.Millisecond)
+	}
+	bar.FinishPrint("The End!")
+
+}