1// Copyright 2019 Google Inc. All rights reserved.
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15package main
16
17import (
18	"errors"
19	"path/filepath"
20	"strings"
21)
22
23// Match returns true if name matches pattern using the same rules as filepath.Match, but supporting
24// recursive globs (**).
25func Match(pattern, name string) (bool, error) {
26	if filepath.Base(pattern) == "**" {
27		return false, errors.New("pattern has '**' as last path element")
28	}
29
30	patternDir := pattern[len(pattern)-1] == '/'
31	nameDir := name[len(name)-1] == '/'
32
33	if patternDir != nameDir {
34		return false, nil
35	}
36
37	if nameDir {
38		name = name[:len(name)-1]
39		pattern = pattern[:len(pattern)-1]
40	}
41
42	for {
43		var patternFile, nameFile string
44		pattern, patternFile = filepath.Dir(pattern), filepath.Base(pattern)
45
46		if patternFile == "**" {
47			if strings.Contains(pattern, "**") {
48				return false, errors.New("pattern contains multiple '**'")
49			}
50			// Test if the any prefix of name matches the part of the pattern before **
51			for {
52				if name == "." || name == "/" {
53					return name == pattern, nil
54				}
55				if match, err := filepath.Match(pattern, name); err != nil {
56					return false, err
57				} else if match {
58					return true, nil
59				}
60				name = filepath.Dir(name)
61			}
62		} else if strings.Contains(patternFile, "**") {
63			return false, errors.New("pattern contains other characters between '**' and path separator")
64		}
65
66		name, nameFile = filepath.Dir(name), filepath.Base(name)
67
68		if nameFile == "." && patternFile == "." {
69			return true, nil
70		} else if nameFile == "/" && patternFile == "/" {
71			return true, nil
72		} else if nameFile == "." || patternFile == "." || nameFile == "/" || patternFile == "/" {
73			return false, nil
74		}
75
76		match, err := filepath.Match(patternFile, nameFile)
77		if err != nil || !match {
78			return match, err
79		}
80	}
81}
82