[Golang] Convert size in bytes to Bytes, Kilobytes, Megabytes, GB and TB

gistfile1.txt

package main

import (
  "fmt"
  "math"
  "strconv"
)

var (
	sizeInMB float64 = 999 // This is in megabytes
	suffixes [5]string
)

func Round(val float64, roundOn float64, places int ) (newVal float64) {
	var round float64
	pow := math.Pow(10, float64(places))
	digit := pow * val
	_, div := math.Modf(digit)
	if div >= roundOn {
		round = math.Ceil(digit)
	} else {
		round = math.Floor(digit)
	}
	newVal = round / pow
	return
}

func main() {
	size := sizeInMB * 1024 * 1024 // This is in bytes
	suffixes[0] = "B"
	suffixes[1] = "KB"
	suffixes[2] = "MB"
	suffixes[3] = "GB"
	suffixes[4] = "TB"
	
	base := math.Log(size)/math.Log(1024)
	getSize := Round(math.Pow(1024, base - math.Floor(base)), .5, 2)
	getSuffix := suffixes[int(math.Floor(base))]
	fmt.Println(strconv.FormatFloat(getSize, 'f', -1, 64)+" "+string(getSuffix))
}

Simpler:

func prettyByteSize(b int) string {
	bf := float64(b)
	for _, unit := range []string{"", "Ki", "Mi", "Gi", "Ti", "Pi", "Ei", "Zi"} {
		if math.Abs(bf) < 1024.0 {
			return fmt.Sprintf("%3.1f%sB", bf, unit)
		}
		bf /= 1024.0
	}
	return fmt.Sprintf("%.1fYiB", bf)
}

Converted from here: https://stackoverflow.com/a/1094933/1333724

@maxmcd thanks 😇