```

var units = []string{" bytes", "KB", "MB", "GB", "TB", "PB"}
func formatBytes(val uint64) string {
    var i int
    var target uint64
    for i = range units {
        target = 1 << uint(10*(i+1))
        if val < target {
            break
        }
    }
    if i > 0 {
        return fmt.Sprintf("%0.2f%s (%d bytes)", float64(val)/(float64(target)/1024), units[i], val)
    }
    return fmt.Sprintf("%d bytes", val)
}

```