match.go raw

   1  // Copyright © 2014 Steve Francia <spf@spf13.com>.
   2  // Copyright 2009 The Go Authors. All rights reserved.
   3  
   4  // Licensed under the Apache License, Version 2.0 (the "License");
   5  // you may not use this file except in compliance with the License.
   6  // You may obtain a copy of the License at
   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  
  15  package afero
  16  
  17  import (
  18  	"path/filepath"
  19  	"sort"
  20  	"strings"
  21  )
  22  
  23  // Glob returns the names of all files matching pattern or nil
  24  // if there is no matching file. The syntax of patterns is the same
  25  // as in Match. The pattern may describe hierarchical names such as
  26  // /usr/*/bin/ed (assuming the Separator is '/').
  27  //
  28  // Glob ignores file system errors such as I/O errors reading directories.
  29  // The only possible returned error is ErrBadPattern, when pattern
  30  // is malformed.
  31  //
  32  // This was adapted from (http://golang.org/pkg/path/filepath) and uses several
  33  // built-ins from that package.
  34  func Glob(fs Fs, pattern string) (matches []string, err error) {
  35  	if !hasMeta(pattern) {
  36  		// Lstat not supported by a ll filesystems.
  37  		if _, err = lstatIfPossible(fs, pattern); err != nil {
  38  			return nil, nil
  39  		}
  40  		return []string{pattern}, nil
  41  	}
  42  
  43  	dir, file := filepath.Split(pattern)
  44  	switch dir {
  45  	case "":
  46  		dir = "."
  47  	case string(filepath.Separator):
  48  	// nothing
  49  	default:
  50  		dir = dir[0 : len(dir)-1] // chop off trailing separator
  51  	}
  52  
  53  	if !hasMeta(dir) {
  54  		return glob(fs, dir, file, nil)
  55  	}
  56  
  57  	var m []string
  58  	m, err = Glob(fs, dir)
  59  	if err != nil {
  60  		return
  61  	}
  62  	for _, d := range m {
  63  		matches, err = glob(fs, d, file, matches)
  64  		if err != nil {
  65  			return
  66  		}
  67  	}
  68  	return
  69  }
  70  
  71  // glob searches for files matching pattern in the directory dir
  72  // and appends them to matches. If the directory cannot be
  73  // opened, it returns the existing matches. New matches are
  74  // added in lexicographical order.
  75  func glob(fs Fs, dir, pattern string, matches []string) (m []string, e error) {
  76  	m = matches
  77  	fi, err := fs.Stat(dir)
  78  	if err != nil {
  79  		return
  80  	}
  81  	if !fi.IsDir() {
  82  		return
  83  	}
  84  	d, err := fs.Open(dir)
  85  	if err != nil {
  86  		return
  87  	}
  88  	defer d.Close()
  89  
  90  	names, _ := d.Readdirnames(-1)
  91  	sort.Strings(names)
  92  
  93  	for _, n := range names {
  94  		matched, err := filepath.Match(pattern, n)
  95  		if err != nil {
  96  			return m, err
  97  		}
  98  		if matched {
  99  			m = append(m, filepath.Join(dir, n))
 100  		}
 101  	}
 102  	return
 103  }
 104  
 105  // hasMeta reports whether path contains any of the magic characters
 106  // recognized by Match.
 107  func hasMeta(path string) bool {
 108  	// TODO(niemeyer): Should other magic characters be added here?
 109  	return strings.ContainsAny(path, "*?[")
 110  }
 111