Disk Usage info like `df -h` for Golang

diskusage.go

package main

import (
	"fmt"
	syscall "golang.org/x/sys/unix"
)

type DiskStatus struct {
	All  uint64 `json:"all"`
	Used uint64 `json:"used"`
	Free uint64 `json:"free"`
	Avail uint64 `json:"avail"`
}

// disk usage of path/disk
func DiskUsage(path string) (disk DiskStatus) {
	fs := syscall.Statfs_t{}
	err := syscall.Statfs(path, &fs)
	if err != nil {
		return
	}
	disk.All = fs.Blocks * uint64(fs.Bsize)
	disk.Avail = fs.Bavail * uint64(fs.Bsize)
	disk.Free = fs.Bfree * uint64(fs.Bsize)
	disk.Used = disk.All - disk.Free
	return
}

const (
	B  = 1
	KB = 1024 * B
	MB = 1024 * KB
	GB = 1024 * MB
)

func main() {
	disk := DiskUsage("/")
	fmt.Printf("All: %.2f GB\n", float64(disk.All)/float64(GB))
	fmt.Printf("Avail: %.2f GB\n", float64(disk.Avail)/float64(GB))
	fmt.Printf("Used: %.2f GB\n", float64(disk.Used)/float64(GB))
}

disk.Used data is not correct on Mac. It should be disk.All - disk. Avail