// download a file with the HTTP/HTTPS protocol showing a progress bar. The destination file is
// always overwritten.
func download(rawurl string, destinationPath string) {
tempDestinationPath := destinationPath + ".tmp"
destination, err := os.Create(tempDestinationPath)
if err != nil {
log.Fatalf("Unable to open the destination file: %s", tempDestinationPath)
}
defer destination.Close()
response, err := customGet(rawurl)
if err != nil {
log.Fatalf("Unable to open a connection to %s", rawurl)
}
defer response.Body.Close()
if response.StatusCode != http.StatusOK {
log.Fatalf("Unexpected HTTP response code. Wanted 200 but got %d", response.StatusCode)
}
var progressBar *pb.ProgressBar
contentLength, err := strconv.Atoi(response.Header.Get("Content-Length"))
if err == nil {
progressBar = pb.New(int(contentLength))
} else {
progressBar = pb.New(0)
}
defer progressBar.Finish()
progressBar.ShowSpeed = true
progressBar.SetRefreshRate(time.Millisecond * 1000)
progressBar.SetUnits(pb.U_BYTES)
progressBar.Start()
writer := io.MultiWriter(destination, progressBar)
io.Copy(writer, response.Body)
destination.Close()
os.Rename(tempDestinationPath, destinationPath)
}