code review 163085: move ReadFile, WriteFile, and ReadDir into a separate i...

src/cmd/gofmt/gofmt.go

 // Copyright 2009 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 package main
 
 import (
         "bytes";
         "flag";
         "fmt";
         "go/ast";
         "go/parser";
         "go/printer";
         "go/scanner";
-        "io";
+        "io/ioutil";
         "os";
         pathutil "path";
         "strings";
 )
 
 
 var (
         // main operation modes
         list            = flag.Bool("l", false, "list files whose formatting differs from gofmt's");
         write           = flag.Bool("w", false, "write result to (source) file instead of stdout");
@@ skipping 53 matching lines @@
 }
 
 
 func isGoFile(d *os.Dir) bool {
         // ignore non-Go files
         return d.IsRegular() && !strings.HasPrefix(d.Name, ".") && strings.HasSuffix(d.Name, ".go")
 }
 
 
 func processFile(f *os.File) os.Error {
-        src, err := io.ReadAll(f);
+        src, err := ioutil.ReadAll(f);
         if err != nil {
                 return err
         }
 
         file, err := parser.ParseFile(f.Name(), src, parserMode);
         if err != nil {
                 return err
         }
 
         if rewrite != nil {
                 file = rewrite(file)
         }
 
         var res bytes.Buffer;
         _, err = (&printer.Config{printerMode, *tabwidth, nil}).Fprint(&res, file);
         if err != nil {
                 return err
         }
 
         if bytes.Compare(src, res.Bytes()) != 0 {
                 // formatting has changed
                 if *list {
                         fmt.Fprintln(os.Stdout, f.Name())
                 }
                 if *write {
-                        err = io.WriteFile(f.Name(), res.Bytes(), 0);
+                        err = ioutil.WriteFile(f.Name(), res.Bytes(), 0);
                         if err != nil {
                                 return err
                         }
                 }
         }
 
         if !*list && !*write {
                 _, err = os.Stdout.Write(res.Bytes())
         }
 
@@ skipping 74 matching lines @@
                         if err := processFileByName(path); err != nil {
                                 report(err)
                         }
                 case dir.IsDirectory():
                         walkDir(path)
                 }
         }
 
         os.Exit(exitCode);
 }