format.go

package main

import (
	"fmt"
	"time"
)

func byteCountIEC(b int64) string {
	const unit = 1024
	if b < unit {
		return fmt.Sprintf("%d B", b)
	}

	div, exp := int64(unit), 0
	for n := b / unit; n >= unit; n /= unit {
		div *= unit
		exp++
	}

	return fmt.Sprintf("%.1f %ciB", float64(b)/float64(div), "KMGTPE"[exp])
}

func relativeTime(t time.Time) string {
	if t.Year() < 1970 {
		return ""
	}

	diff := time.Since(t)

	switch {
	case diff < time.Minute:
		return "just now"
	case diff < time.Hour:
		return fmt.Sprintf("%dm ago", int(diff.Minutes()))
	case diff < 24*time.Hour:
		return fmt.Sprintf("%dh ago", int(diff.Hours()))
	case diff < 7*24*time.Hour:
		return fmt.Sprintf("%dd ago", int(diff.Hours()/24))
	case diff < 30*24*time.Hour:
		return fmt.Sprintf("%dw ago", int(diff.Hours()/24/7))
	case diff < 365*24*time.Hour:
		return fmt.Sprintf("%dmo ago", int(diff.Hours()/24/30))
	default:
		return fmt.Sprintf("%dy ago", int(diff.Hours()/24/365))
	}
}