1// Copyright 2011 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
7func isExist(err error) bool {
8	switch pe := err.(type) {
9	case nil:
10		return false
11	case *PathError:
12		err = pe.Err
13	case *LinkError:
14		err = pe.Err
15	case *SyscallError:
16		err = pe.Err
17	}
18	return contains(err.Error(), " exists")
19}
20
21func isNotExist(err error) bool {
22	switch pe := err.(type) {
23	case nil:
24		return false
25	case *PathError:
26		err = pe.Err
27	case *LinkError:
28		err = pe.Err
29	case *SyscallError:
30		err = pe.Err
31	}
32	return contains(err.Error(), "does not exist") || contains(err.Error(), "not found") ||
33		contains(err.Error(), "has been removed") || contains(err.Error(), "no parent")
34}
35
36func isPermission(err error) bool {
37	switch pe := err.(type) {
38	case nil:
39		return false
40	case *PathError:
41		err = pe.Err
42	case *LinkError:
43		err = pe.Err
44	case *SyscallError:
45		err = pe.Err
46	}
47	return contains(err.Error(), "permission denied")
48}
49
50// contains is a local version of strings.Contains. It knows len(sep) > 1.
51func contains(s, sep string) bool {
52	n := len(sep)
53	c := sep[0]
54	for i := 0; i+n <= len(s); i++ {
55		if s[i] == c && s[i:i+n] == sep {
56			return true
57		}
58	}
59	return false
60}
61