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
5package os
6
7import (
8	"errors"
9)
10
11// Portable analogs of some common system call errors.
12var (
13	ErrInvalid    = errors.New("invalid argument")
14	ErrPermission = errors.New("permission denied")
15	ErrExist      = errors.New("file already exists")
16	ErrNotExist   = errors.New("file does not exist")
17)
18
19// PathError records an error and the operation and file path that caused it.
20type PathError struct {
21	Op   string
22	Path string
23	Err  error
24}
25
26func (e *PathError) Error() string { return e.Op + " " + e.Path + ": " + e.Err.Error() }
27
28// SyscallError records an error from a specific system call.
29type SyscallError struct {
30	Syscall string
31	Err     error
32}
33
34func (e *SyscallError) Error() string { return e.Syscall + ": " + e.Err.Error() }
35
36// NewSyscallError returns, as an error, a new SyscallError
37// with the given system call name and error details.
38// As a convenience, if err is nil, NewSyscallError returns nil.
39func NewSyscallError(syscall string, err error) error {
40	if err == nil {
41		return nil
42	}
43	return &SyscallError{syscall, err}
44}
45
46// IsExist returns a boolean indicating whether the error is known to report
47// that a file or directory already exists. It is satisfied by ErrExist as
48// well as some syscall errors.
49func IsExist(err error) bool {
50	return isExist(err)
51}
52
53// IsNotExist returns a boolean indicating whether the error is known to
54// report that a file or directory does not exist. It is satisfied by
55// ErrNotExist as well as some syscall errors.
56func IsNotExist(err error) bool {
57	return isNotExist(err)
58}
59
60// IsPermission returns a boolean indicating whether the error is known to
61// report that permission is denied. It is satisfied by ErrPermission as well
62// as some syscall errors.
63func IsPermission(err error) bool {
64	return isPermission(err)
65}
66