Make human-readable number strings.

humannumber.go

// humanNumber turns long numbers into sensible units for file sizes etc.
// Converted from C code found on the web.
func humanNumber(n int, si bool) string {
	num := float64(n)
	var unit float64 = 1024
	if si {
		unit = 1000
	}
	if num < unit {
		return fmt.Sprintf("%dB", int(num))
	}
	exp := int(math.Log(num) / math.Log(unit))
	pre := "kMGTPE"
	if !si {
		pre = "KMGTPE"
		pre = pre[exp-1:exp] + "i"
	} else {
		pre = pre[exp-1 : exp]
	}
	r := n / int(math.Pow(unit, float64(exp)))
	return fmt.Sprintf("%d %sB", r, pre)
}