syscall.go 2.6 KB

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  1. // Copyright 2009 The Go Authors. All rights reserved.
  2. // Use of this source code is governed by a BSD-style
  3. // license that can be found in the LICENSE file.
  4. // +build darwin dragonfly freebsd linux netbsd openbsd solaris
  5. // Package unix contains an interface to the low-level operating system
  6. // primitives. OS details vary depending on the underlying system, and
  7. // by default, godoc will display OS-specific documentation for the current
  8. // system. If you want godoc to display OS documentation for another
  9. // system, set $GOOS and $GOARCH to the desired system. For example, if
  10. // you want to view documentation for freebsd/arm on linux/amd64, set $GOOS
  11. // to freebsd and $GOARCH to arm.
  12. // The primary use of this package is inside other packages that provide a more
  13. // portable interface to the system, such as "os", "time" and "net". Use
  14. // those packages rather than this one if you can.
  15. // For details of the functions and data types in this package consult
  16. // the manuals for the appropriate operating system.
  17. // These calls return err == nil to indicate success; otherwise
  18. // err represents an operating system error describing the failure and
  19. // holds a value of type syscall.Errno.
  20. package unix // import "golang.org/x/sys/unix"
  21. import "unsafe"
  22. // ByteSliceFromString returns a NUL-terminated slice of bytes
  23. // containing the text of s. If s contains a NUL byte at any
  24. // location, it returns (nil, EINVAL).
  25. func ByteSliceFromString(s string) ([]byte, error) {
  26. for i := 0; i < len(s); i++ {
  27. if s[i] == 0 {
  28. return nil, EINVAL
  29. }
  30. }
  31. a := make([]byte, len(s)+1)
  32. copy(a, s)
  33. return a, nil
  34. }
  35. // BytePtrFromString returns a pointer to a NUL-terminated array of
  36. // bytes containing the text of s. If s contains a NUL byte at any
  37. // location, it returns (nil, EINVAL).
  38. func BytePtrFromString(s string) (*byte, error) {
  39. a, err := ByteSliceFromString(s)
  40. if err != nil {
  41. return nil, err
  42. }
  43. return &a[0], nil
  44. }
  45. // Single-word zero for use when we need a valid pointer to 0 bytes.
  46. // See mkunix.pl.
  47. var _zero uintptr
  48. func (ts *Timespec) Unix() (sec int64, nsec int64) {
  49. return int64(ts.Sec), int64(ts.Nsec)
  50. }
  51. func (tv *Timeval) Unix() (sec int64, nsec int64) {
  52. return int64(tv.Sec), int64(tv.Usec) * 1000
  53. }
  54. func (ts *Timespec) Nano() int64 {
  55. return int64(ts.Sec)*1e9 + int64(ts.Nsec)
  56. }
  57. func (tv *Timeval) Nano() int64 {
  58. return int64(tv.Sec)*1e9 + int64(tv.Usec)*1000
  59. }
  60. func TimevalToNsec(tv Timeval) int64 { return int64(tv.Sec)*1e9 + int64(tv.Usec)*1e3 }
  61. // use is a no-op, but the compiler cannot see that it is.
  62. // Calling use(p) ensures that p is kept live until that point.
  63. //go:noescape
  64. func use(p unsafe.Pointer)