flag.go 540 B

12345678910111213141516171819202122232425262728293031
  1. // Copyright (c) Tailscale Inc & AUTHORS
  2. // SPDX-License-Identifier: BSD-3-Clause
  3. package main
  4. import "strconv"
  5. // boolFlag is a flag.Value that tracks whether it was ever set.
  6. type boolFlag struct {
  7. set bool
  8. v bool
  9. }
  10. func (b *boolFlag) String() string {
  11. if b == nil || !b.set {
  12. return "unset"
  13. }
  14. return strconv.FormatBool(b.v)
  15. }
  16. func (b *boolFlag) Set(s string) error {
  17. v, err := strconv.ParseBool(s)
  18. if err != nil {
  19. return err
  20. }
  21. b.v = v
  22. b.set = true
  23. return nil
  24. }
  25. func (b *boolFlag) IsBoolFlag() bool { return true }