import (
	"io/fs"
	"os/user"
	"runtime"
	"strconv"
	"sync"
	"syscall"
)

func init() {
	sysStat = statUnix
}

// userMap and groupMap caches UID and GID lookups for performance reasons.
// The downside is that renaming uname or gname by the OS never takes effect.
var userMap, groupMap sync.Map // map[int]string

func statUnix(fi fs.FileInfo, h *Header, doNameLookups bool) error {
	sys, ok := fi.Sys().(*syscall.Stat_t)