libgo/go/os/path.go

   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
   5 package os
   6
   7 import (
   8         "syscall"
   9 )
  10
  11 // MkdirAll creates a directory named path,
  12 // along with any necessary parents, and returns nil,
  13 // or else returns an error.
  14 // The permission bits perm (before umask) are used for all
  15 // directories that MkdirAll creates.
  16 // If path is already a directory, MkdirAll does nothing
  17 // and returns nil.
  18 func MkdirAll(path string, perm FileMode) error {
  19         // Fast path: if we can tell whether path is a directory or file, stop with success or error.
  20         dir, err := Stat(path)
  21         if err == nil {
  22                 if dir.IsDir() {
  23                         return nil
  24                 }
  25                 return &PathError{"mkdir", path, syscall.ENOTDIR}
  26         }
  27
  28         // Slow path: make sure parent exists and then call Mkdir for path.
  29         i := len(path)
  30         for i > 0 && IsPathSeparator(path[i-1]) { // Skip trailing path separator.
  31                 i--
  32         }
  33
  34         j := i
  35         for j > 0 && !IsPathSeparator(path[j-1]) { // Scan backward over element.
  36                 j--
  37         }
  38
  39         if j > 1 {
  40                 // Create parent.
  41                 err = MkdirAll(fixRootDirectory(path[:j-1]), perm)
  42                 if err != nil {
  43                         return err
  44                 }
  45         }
  46
  47         // Parent now exists; invoke Mkdir and use its result.
  48         err = Mkdir(path, perm)
  49         if err != nil {
  50                 // Handle arguments like "foo/." by
  51                 // double-checking that directory doesn't exist.
  52                 dir, err1 := Lstat(path)
  53                 if err1 == nil && dir.IsDir() {
  54                         return nil
  55                 }
  56                 return err
  57         }
  58         return nil
  59 }
  60
  61 // endsWithDot reports whether the final component of path is ".".
  62 func endsWithDot(path string) bool {
  63         if path == "." {
  64                 return true
  65         }
  66         if len(path) >= 2 && path[len(path)-1] == '.' && IsPathSeparator(path[len(path)-2]) {
  67                 return true
  68         }
  69         return false
  70 }