path.go raw

   1  // Copyright ©2015 The Go Authors
   2  // Copyright ©2015 Steve Francia <spf@spf13.com>
   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  //
   8  //     http://www.apache.org/licenses/LICENSE-2.0
   9  //
  10  // Unless required by applicable law or agreed to in writing, software
  11  // distributed under the License is distributed on an "AS IS" BASIS,
  12  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  13  // See the License for the specific language governing permissions and
  14  // limitations under the License.
  15  
  16  package afero
  17  
  18  import (
  19  	"os"
  20  	"path/filepath"
  21  	"sort"
  22  )
  23  
  24  // readDirNames reads the directory named by dirname and returns
  25  // a sorted list of directory entries.
  26  // adapted from https://golang.org/src/path/filepath/path.go
  27  func readDirNames(fs Fs, dirname string) ([]string, error) {
  28  	f, err := fs.Open(dirname)
  29  	if err != nil {
  30  		return nil, err
  31  	}
  32  	names, err := f.Readdirnames(-1)
  33  	f.Close()
  34  	if err != nil {
  35  		return nil, err
  36  	}
  37  	sort.Strings(names)
  38  	return names, nil
  39  }
  40  
  41  // walk recursively descends path, calling walkFn
  42  // adapted from https://golang.org/src/path/filepath/path.go
  43  func walk(fs Fs, path string, info os.FileInfo, walkFn filepath.WalkFunc) error {
  44  	err := walkFn(path, info, nil)
  45  	if err != nil {
  46  		if info.IsDir() && err == filepath.SkipDir {
  47  			return nil
  48  		}
  49  		return err
  50  	}
  51  
  52  	if !info.IsDir() {
  53  		return nil
  54  	}
  55  
  56  	names, err := readDirNames(fs, path)
  57  	if err != nil {
  58  		return walkFn(path, info, err)
  59  	}
  60  
  61  	for _, name := range names {
  62  		filename := filepath.Join(path, name)
  63  		fileInfo, err := lstatIfPossible(fs, filename)
  64  		if err != nil {
  65  			if err := walkFn(filename, fileInfo, err); err != nil && err != filepath.SkipDir {
  66  				return err
  67  			}
  68  		} else {
  69  			err = walk(fs, filename, fileInfo, walkFn)
  70  			if err != nil {
  71  				if !fileInfo.IsDir() || err != filepath.SkipDir {
  72  					return err
  73  				}
  74  			}
  75  		}
  76  	}
  77  	return nil
  78  }
  79  
  80  // if the filesystem supports it, use Lstat, else use fs.Stat
  81  func lstatIfPossible(fs Fs, path string) (os.FileInfo, error) {
  82  	if lfs, ok := fs.(Lstater); ok {
  83  		fi, _, err := lfs.LstatIfPossible(path)
  84  		return fi, err
  85  	}
  86  	return fs.Stat(path)
  87  }
  88  
  89  // Walk walks the file tree rooted at root, calling walkFn for each file or
  90  // directory in the tree, including root. All errors that arise visiting files
  91  // and directories are filtered by walkFn. The files are walked in lexical
  92  // order, which makes the output deterministic but means that for very
  93  // large directories Walk can be inefficient.
  94  // Walk does not follow symbolic links.
  95  
  96  func (a Afero) Walk(root string, walkFn filepath.WalkFunc) error {
  97  	return Walk(a.Fs, root, walkFn)
  98  }
  99  
 100  func Walk(fs Fs, root string, walkFn filepath.WalkFunc) error {
 101  	info, err := lstatIfPossible(fs, root)
 102  	if err != nil {
 103  		return walkFn(root, nil, err)
 104  	}
 105  	return walk(fs, root, info, walkFn)
 106  }
 107