libgo/go/syscall/syscall_errno.go

   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
   5 package syscall
   6
   7 import "internal/oserror"
   8
   9 // An Errno is an unsigned number describing an error condition.
  10 // It implements the error interface. The zero Errno is by convention
  11 // a non-error, so code to convert from Errno to error should use:
  12 //
  13 //      err = nil
  14 //      if errno != 0 {
  15 //              err = errno
  16 //      }
  17 //
  18 // Errno values can be tested against error values from the os package
  19 // using errors.Is. For example:
  20 //
  21 //      _, _, err := syscall.Syscall(...)
  22 //      if errors.Is(err, fs.ErrNotExist) ...
  23 type Errno uintptr
  24
  25 func (e Errno) Error() string {
  26         return Errstr(int(e))
  27 }
  28
  29 func (e Errno) Is(target error) bool {
  30         switch target {
  31         case oserror.ErrPermission:
  32                 return e == EACCES || e == EPERM
  33         case oserror.ErrExist:
  34                 return e == EEXIST || e == ENOTEMPTY
  35         case oserror.ErrNotExist:
  36                 return e == ENOENT
  37         }
  38         return false
  39 }
  40
  41 func (e Errno) Temporary() bool {
  42         return e == EINTR || e == EMFILE || e == ENFILE || e.Timeout()
  43 }
  44
  45 func (e Errno) Timeout() bool {
  46         return e == EAGAIN || e == EWOULDBLOCK || e == ETIMEDOUT
  47 }