Imported Upstream version 1.4upstream/1.4

1 files changed, 1484 insertions, 0 deletions

diff --git a/src/os/os_test.go b/src/os/os_test.go
new file mode 100644
index 000000000..a30a2b031
--- /dev/null
+++ b/src/os/os_test.go
@@ -0,0 +1,1484 @@
+// 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 os_test
+
+import (
+	"bytes"
+	"errors"
+	"flag"
+	"fmt"
+	"io"
+	"io/ioutil"
+	. "os"
+	osexec "os/exec"
+	"path/filepath"
+	"reflect"
+	"runtime"
+	"sort"
+	"strings"
+	"sync"
+	"syscall"
+	"testing"
+	"text/template"
+	"time"
+)
+
+var supportsSymlinks = true
+
+var dot = []string{
+	"dir_unix.go",
+	"env.go",
+	"error.go",
+	"file.go",
+	"os_test.go",
+	"types.go",
+	"stat_darwin.go",
+	"stat_linux.go",
+}
+
+type sysDir struct {
+	name  string
+	files []string
+}
+
+var sysdir = func() (sd *sysDir) {
+	switch runtime.GOOS {
+	case "android":
+		sd = &sysDir{
+			"/system/etc",
+			[]string{
+				"audio_policy.conf",
+				"system_fonts.xml",
+			},
+		}
+	case "windows":
+		sd = &sysDir{
+			Getenv("SystemRoot") + "\\system32\\drivers\\etc",
+			[]string{
+				"networks",
+				"protocol",
+				"services",
+			},
+		}
+	case "plan9":
+		sd = &sysDir{
+			"/lib/ndb",
+			[]string{
+				"common",
+				"local",
+			},
+		}
+	default:
+		sd = &sysDir{
+			"/etc",
+			[]string{
+				"group",
+				"hosts",
+				"passwd",
+			},
+		}
+	}
+	return
+}()
+
+func size(name string, t *testing.T) int64 {
+	file, err := Open(name)
+	if err != nil {
+		t.Fatal("open failed:", err)
+	}
+	defer file.Close()
+	var buf [100]byte
+	len := 0
+	for {
+		n, e := file.Read(buf[0:])
+		len += n
+		if e == io.EOF {
+			break
+		}
+		if e != nil {
+			t.Fatal("read failed:", err)
+		}
+	}
+	return int64(len)
+}
+
+func equal(name1, name2 string) (r bool) {
+	switch runtime.GOOS {
+	case "windows":
+		r = strings.ToLower(name1) == strings.ToLower(name2)
+	default:
+		r = name1 == name2
+	}
+	return
+}
+
+func newFile(testName string, t *testing.T) (f *File) {
+	// Use a local file system, not NFS.
+	// On Unix, override $TMPDIR in case the user
+	// has it set to an NFS-mounted directory.
+	dir := ""
+	if runtime.GOOS != "android" && runtime.GOOS != "windows" {
+		dir = "/tmp"
+	}
+	f, err := ioutil.TempFile(dir, "_Go_"+testName)
+	if err != nil {
+		t.Fatalf("TempFile %s: %s", testName, err)
+	}
+	return
+}
+
+func newDir(testName string, t *testing.T) (name string) {
+	// Use a local file system, not NFS.
+	// On Unix, override $TMPDIR in case the user
+	// has it set to an NFS-mounted directory.
+	dir := ""
+	if runtime.GOOS != "android" && runtime.GOOS != "windows" {
+		dir = "/tmp"
+	}
+	name, err := ioutil.TempDir(dir, "_Go_"+testName)
+	if err != nil {
+		t.Fatalf("TempDir %s: %s", testName, err)
+	}
+	return
+}
+
+var sfdir = sysdir.name
+var sfname = sysdir.files[0]
+
+func TestStat(t *testing.T) {
+	path := sfdir + "/" + sfname
+	dir, err := Stat(path)
+	if err != nil {
+		t.Fatal("stat failed:", err)
+	}
+	if !equal(sfname, dir.Name()) {
+		t.Error("name should be ", sfname, "; is", dir.Name())
+	}
+	filesize := size(path, t)
+	if dir.Size() != filesize {
+		t.Error("size should be", filesize, "; is", dir.Size())
+	}
+}
+
+func TestFstat(t *testing.T) {
+	path := sfdir + "/" + sfname
+	file, err1 := Open(path)
+	if err1 != nil {
+		t.Fatal("open failed:", err1)
+	}
+	defer file.Close()
+	dir, err2 := file.Stat()
+	if err2 != nil {
+		t.Fatal("fstat failed:", err2)
+	}
+	if !equal(sfname, dir.Name()) {
+		t.Error("name should be ", sfname, "; is", dir.Name())
+	}
+	filesize := size(path, t)
+	if dir.Size() != filesize {
+		t.Error("size should be", filesize, "; is", dir.Size())
+	}
+}
+
+func TestLstat(t *testing.T) {
+	path := sfdir + "/" + sfname
+	dir, err := Lstat(path)
+	if err != nil {
+		t.Fatal("lstat failed:", err)
+	}
+	if !equal(sfname, dir.Name()) {
+		t.Error("name should be ", sfname, "; is", dir.Name())
+	}
+	filesize := size(path, t)
+	if dir.Size() != filesize {
+		t.Error("size should be", filesize, "; is", dir.Size())
+	}
+}
+
+// Read with length 0 should not return EOF.
+func TestRead0(t *testing.T) {
+	path := sfdir + "/" + sfname
+	f, err := Open(path)
+	if err != nil {
+		t.Fatal("open failed:", err)
+	}
+	defer f.Close()
+
+	b := make([]byte, 0)
+	n, err := f.Read(b)
+	if n != 0 || err != nil {
+		t.Errorf("Read(0) = %d, %v, want 0, nil", n, err)
+	}
+	b = make([]byte, 100)
+	n, err = f.Read(b)
+	if n <= 0 || err != nil {
+		t.Errorf("Read(100) = %d, %v, want >0, nil", n, err)
+	}
+}
+
+func testReaddirnames(dir string, contents []string, t *testing.T) {
+	file, err := Open(dir)
+	if err != nil {
+		t.Fatalf("open %q failed: %v", dir, err)
+	}
+	defer file.Close()
+	s, err2 := file.Readdirnames(-1)
+	if err2 != nil {
+		t.Fatalf("readdirnames %q failed: %v", dir, err2)
+	}
+	for _, m := range contents {
+		found := false
+		for _, n := range s {
+			if n == "." || n == ".." {
+				t.Errorf("got %s in directory", n)
+			}
+			if equal(m, n) {
+				if found {
+					t.Error("present twice:", m)
+				}
+				found = true
+			}
+		}
+		if !found {
+			t.Error("could not find", m)
+		}
+	}
+}
+
+func testReaddir(dir string, contents []string, t *testing.T) {
+	file, err := Open(dir)
+	if err != nil {
+		t.Fatalf("open %q failed: %v", dir, err)
+	}
+	defer file.Close()
+	s, err2 := file.Readdir(-1)
+	if err2 != nil {
+		t.Fatalf("readdir %q failed: %v", dir, err2)
+	}
+	for _, m := range contents {
+		found := false
+		for _, n := range s {
+			if equal(m, n.Name()) {
+				if found {
+					t.Error("present twice:", m)
+				}
+				found = true
+			}
+		}
+		if !found {
+			t.Error("could not find", m)
+		}
+	}
+}
+
+func TestReaddirnames(t *testing.T) {
+	testReaddirnames(".", dot, t)
+	testReaddirnames(sysdir.name, sysdir.files, t)
+}
+
+func TestReaddir(t *testing.T) {
+	testReaddir(".", dot, t)
+	testReaddir(sysdir.name, sysdir.files, t)
+}
+
+// Read the directory one entry at a time.
+func smallReaddirnames(file *File, length int, t *testing.T) []string {
+	names := make([]string, length)
+	count := 0
+	for {
+		d, err := file.Readdirnames(1)
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			t.Fatalf("readdirnames %q failed: %v", file.Name(), err)
+		}
+		if len(d) == 0 {
+			t.Fatalf("readdirnames %q returned empty slice and no error", file.Name())
+		}
+		names[count] = d[0]
+		count++
+	}
+	return names[0:count]
+}
+
+// Check that reading a directory one entry at a time gives the same result
+// as reading it all at once.
+func TestReaddirnamesOneAtATime(t *testing.T) {
+	// big directory that doesn't change often.
+	dir := "/usr/bin"
+	switch runtime.GOOS {
+	case "android":
+		dir = "/system/bin"
+	case "plan9":
+		dir = "/bin"
+	case "windows":
+		dir = Getenv("SystemRoot") + "\\system32"
+	}
+	file, err := Open(dir)
+	if err != nil {
+		t.Fatalf("open %q failed: %v", dir, err)
+	}
+	defer file.Close()
+	all, err1 := file.Readdirnames(-1)
+	if err1 != nil {
+		t.Fatalf("readdirnames %q failed: %v", dir, err1)
+	}
+	file1, err2 := Open(dir)
+	if err2 != nil {
+		t.Fatalf("open %q failed: %v", dir, err2)
+	}
+	defer file1.Close()
+	small := smallReaddirnames(file1, len(all)+100, t) // +100 in case we screw up
+	if len(small) < len(all) {
+		t.Fatalf("len(small) is %d, less than %d", len(small), len(all))
+	}
+	for i, n := range all {
+		if small[i] != n {
+			t.Errorf("small read %q mismatch: %v", small[i], n)
+		}
+	}
+}
+
+func TestReaddirNValues(t *testing.T) {
+	if testing.Short() {
+		t.Skip("test.short; skipping")
+	}
+	dir, err := ioutil.TempDir("", "")
+	if err != nil {
+		t.Fatalf("TempDir: %v", err)
+	}
+	defer RemoveAll(dir)
+	for i := 1; i <= 105; i++ {
+		f, err := Create(filepath.Join(dir, fmt.Sprintf("%d", i)))
+		if err != nil {
+			t.Fatalf("Create: %v", err)
+		}
+		f.Write([]byte(strings.Repeat("X", i)))
+		f.Close()
+	}
+
+	var d *File
+	openDir := func() {
+		var err error
+		d, err = Open(dir)
+		if err != nil {
+			t.Fatalf("Open directory: %v", err)
+		}
+	}
+
+	readDirExpect := func(n, want int, wantErr error) {
+		fi, err := d.Readdir(n)
+		if err != wantErr {
+			t.Fatalf("Readdir of %d got error %v, want %v", n, err, wantErr)
+		}
+		if g, e := len(fi), want; g != e {
+			t.Errorf("Readdir of %d got %d files, want %d", n, g, e)
+		}
+	}
+
+	readDirNamesExpect := func(n, want int, wantErr error) {
+		fi, err := d.Readdirnames(n)
+		if err != wantErr {
+			t.Fatalf("Readdirnames of %d got error %v, want %v", n, err, wantErr)
+		}
+		if g, e := len(fi), want; g != e {
+			t.Errorf("Readdirnames of %d got %d files, want %d", n, g, e)
+		}
+	}
+
+	for _, fn := range []func(int, int, error){readDirExpect, readDirNamesExpect} {
+		// Test the slurp case
+		openDir()
+		fn(0, 105, nil)
+		fn(0, 0, nil)
+		d.Close()
+
+		// Slurp with -1 instead
+		openDir()
+		fn(-1, 105, nil)
+		fn(-2, 0, nil)
+		fn(0, 0, nil)
+		d.Close()
+
+		// Test the bounded case
+		openDir()
+		fn(1, 1, nil)
+		fn(2, 2, nil)
+		fn(105, 102, nil) // and tests buffer >100 case
+		fn(3, 0, io.EOF)
+		d.Close()
+	}
+}
+
+func touch(t *testing.T, name string) {
+	f, err := Create(name)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := f.Close(); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestReaddirStatFailures(t *testing.T) {
+	switch runtime.GOOS {
+	case "windows", "plan9":
+		// Windows and Plan 9 already do this correctly,
+		// but are structured with different syscalls such
+		// that they don't use Lstat, so the hook below for
+		// testing it wouldn't work.
+		t.Skipf("skipping test on %v", runtime.GOOS)
+	}
+	dir, err := ioutil.TempDir("", "")
+	if err != nil {
+		t.Fatalf("TempDir: %v", err)
+	}
+	defer RemoveAll(dir)
+	touch(t, filepath.Join(dir, "good1"))
+	touch(t, filepath.Join(dir, "x")) // will disappear or have an error
+	touch(t, filepath.Join(dir, "good2"))
+	defer func() {
+		*LstatP = Lstat
+	}()
+	var xerr error // error to return for x
+	*LstatP = func(path string) (FileInfo, error) {
+		if xerr != nil && strings.HasSuffix(path, "x") {
+			return nil, xerr
+		}
+		return Lstat(path)
+	}
+	readDir := func() ([]FileInfo, error) {
+		d, err := Open(dir)
+		if err != nil {
+			t.Fatal(err)
+		}
+		defer d.Close()
+		return d.Readdir(-1)
+	}
+	mustReadDir := func(testName string) []FileInfo {
+		fis, err := readDir()
+		if err != nil {
+			t.Fatalf("%s: Readdir: %v", testName, err)
+		}
+		return fis
+	}
+	names := func(fis []FileInfo) []string {
+		s := make([]string, len(fis))
+		for i, fi := range fis {
+			s[i] = fi.Name()
+		}
+		sort.Strings(s)
+		return s
+	}
+
+	if got, want := names(mustReadDir("inital readdir")),
+		[]string{"good1", "good2", "x"}; !reflect.DeepEqual(got, want) {
+		t.Errorf("initial readdir got %q; want %q", got, want)
+	}
+
+	xerr = ErrNotExist
+	if got, want := names(mustReadDir("with x disappearing")),
+		[]string{"good1", "good2"}; !reflect.DeepEqual(got, want) {
+		t.Errorf("with x disappearing, got %q; want %q", got, want)
+	}
+
+	xerr = errors.New("some real error")
+	if _, err := readDir(); err != xerr {
+		t.Errorf("with a non-ErrNotExist error, got error %v; want %v", err, xerr)
+	}
+}
+
+func TestHardLink(t *testing.T) {
+	// Hardlinks are not supported under windows or Plan 9.
+	if runtime.GOOS == "plan9" {
+		return
+	}
+	from, to := "hardlinktestfrom", "hardlinktestto"
+	Remove(from) // Just in case.
+	file, err := Create(to)
+	if err != nil {
+		t.Fatalf("open %q failed: %v", to, err)
+	}
+	defer Remove(to)
+	if err = file.Close(); err != nil {
+		t.Errorf("close %q failed: %v", to, err)
+	}
+	err = Link(to, from)
+	if err != nil {
+		t.Fatalf("link %q, %q failed: %v", to, from, err)
+	}
+	defer Remove(from)
+	tostat, err := Stat(to)
+	if err != nil {
+		t.Fatalf("stat %q failed: %v", to, err)
+	}
+	fromstat, err := Stat(from)
+	if err != nil {
+		t.Fatalf("stat %q failed: %v", from, err)
+	}
+	if !SameFile(tostat, fromstat) {
+		t.Errorf("link %q, %q did not create hard link", to, from)
+	}
+}
+
+func TestSymlink(t *testing.T) {
+	switch runtime.GOOS {
+	case "android", "nacl", "plan9":
+		t.Skipf("skipping on %s", runtime.GOOS)
+	case "windows":
+		if !supportsSymlinks {
+			t.Skipf("skipping on %s", runtime.GOOS)
+		}
+	}
+	from, to := "symlinktestfrom", "symlinktestto"
+	Remove(from) // Just in case.
+	file, err := Create(to)
+	if err != nil {
+		t.Fatalf("open %q failed: %v", to, err)
+	}
+	defer Remove(to)
+	if err = file.Close(); err != nil {
+		t.Errorf("close %q failed: %v", to, err)
+	}
+	err = Symlink(to, from)
+	if err != nil {
+		t.Fatalf("symlink %q, %q failed: %v", to, from, err)
+	}
+	defer Remove(from)
+	tostat, err := Lstat(to)
+	if err != nil {
+		t.Fatalf("stat %q failed: %v", to, err)
+	}
+	if tostat.Mode()&ModeSymlink != 0 {
+		t.Fatalf("stat %q claims to have found a symlink", to)
+	}
+	fromstat, err := Stat(from)
+	if err != nil {
+		t.Fatalf("stat %q failed: %v", from, err)
+	}
+	if !SameFile(tostat, fromstat) {
+		t.Errorf("symlink %q, %q did not create symlink", to, from)
+	}
+	fromstat, err = Lstat(from)
+	if err != nil {
+		t.Fatalf("lstat %q failed: %v", from, err)
+	}
+	if fromstat.Mode()&ModeSymlink == 0 {
+		t.Fatalf("symlink %q, %q did not create symlink", to, from)
+	}
+	fromstat, err = Stat(from)
+	if err != nil {
+		t.Fatalf("stat %q failed: %v", from, err)
+	}
+	if fromstat.Mode()&ModeSymlink != 0 {
+		t.Fatalf("stat %q did not follow symlink", from)
+	}
+	s, err := Readlink(from)
+	if err != nil {
+		t.Fatalf("readlink %q failed: %v", from, err)
+	}
+	if s != to {
+		t.Fatalf("after symlink %q != %q", s, to)
+	}
+	file, err = Open(from)
+	if err != nil {
+		t.Fatalf("open %q failed: %v", from, err)
+	}
+	file.Close()
+}
+
+func TestLongSymlink(t *testing.T) {
+	switch runtime.GOOS {
+	case "plan9", "nacl":
+		t.Skipf("skipping on %s", runtime.GOOS)
+	case "windows":
+		if !supportsSymlinks {
+			t.Skipf("skipping on %s", runtime.GOOS)
+		}
+	}
+	s := "0123456789abcdef"
+	// Long, but not too long: a common limit is 255.
+	s = s + s + s + s + s + s + s + s + s + s + s + s + s + s + s
+	from := "longsymlinktestfrom"
+	Remove(from) // Just in case.
+	err := Symlink(s, from)
+	if err != nil {
+		t.Fatalf("symlink %q, %q failed: %v", s, from, err)
+	}
+	defer Remove(from)
+	r, err := Readlink(from)
+	if err != nil {
+		t.Fatalf("readlink %q failed: %v", from, err)
+	}
+	if r != s {
+		t.Fatalf("after symlink %q != %q", r, s)
+	}
+}
+
+func TestRename(t *testing.T) {
+	from, to := "renamefrom", "renameto"
+	Remove(to) // Just in case.
+	file, err := Create(from)
+	if err != nil {
+		t.Fatalf("open %q failed: %v", to, err)
+	}
+	if err = file.Close(); err != nil {
+		t.Errorf("close %q failed: %v", to, err)
+	}
+	err = Rename(from, to)
+	if err != nil {
+		t.Fatalf("rename %q, %q failed: %v", to, from, err)
+	}
+	defer Remove(to)
+	_, err = Stat(to)
+	if err != nil {
+		t.Errorf("stat %q failed: %v", to, err)
+	}
+}
+
+func exec(t *testing.T, dir, cmd string, args []string, expect string) {
+	r, w, err := Pipe()
+	if err != nil {
+		t.Fatalf("Pipe: %v", err)
+	}
+	defer r.Close()
+	attr := &ProcAttr{Dir: dir, Files: []*File{nil, w, Stderr}}
+	p, err := StartProcess(cmd, args, attr)
+	if err != nil {
+		t.Fatalf("StartProcess: %v", err)
+	}
+	w.Close()
+
+	var b bytes.Buffer
+	io.Copy(&b, r)
+	output := b.String()
+
+	fi1, _ := Stat(strings.TrimSpace(output))
+	fi2, _ := Stat(expect)
+	if !SameFile(fi1, fi2) {
+		t.Errorf("exec %q returned %q wanted %q",
+			strings.Join(append([]string{cmd}, args...), " "), output, expect)
+	}
+	p.Wait()
+}
+
+func TestStartProcess(t *testing.T) {
+	switch runtime.GOOS {
+	case "android", "nacl":
+		t.Skipf("skipping on %s", runtime.GOOS)
+	}
+
+	var dir, cmd string
+	var args []string
+	if runtime.GOOS == "windows" {
+		cmd = Getenv("COMSPEC")
+		dir = Getenv("SystemRoot")
+		args = []string{"/c", "cd"}
+	} else {
+		cmd = "/bin/pwd"
+		dir = "/"
+		args = []string{}
+	}
+	cmddir, cmdbase := filepath.Split(cmd)
+	args = append([]string{cmdbase}, args...)
+	// Test absolute executable path.
+	exec(t, dir, cmd, args, dir)
+	// Test relative executable path.
+	exec(t, cmddir, cmdbase, args, cmddir)
+}
+
+func checkMode(t *testing.T, path string, mode FileMode) {
+	dir, err := Stat(path)
+	if err != nil {
+		t.Fatalf("Stat %q (looking for mode %#o): %s", path, mode, err)
+	}
+	if dir.Mode()&0777 != mode {
+		t.Errorf("Stat %q: mode %#o want %#o", path, dir.Mode(), mode)
+	}
+}
+
+func TestChmod(t *testing.T) {
+	// Chmod is not supported under windows.
+	if runtime.GOOS == "windows" {
+		return
+	}
+	f := newFile("TestChmod", t)
+	defer Remove(f.Name())
+	defer f.Close()
+
+	if err := Chmod(f.Name(), 0456); err != nil {
+		t.Fatalf("chmod %s 0456: %s", f.Name(), err)
+	}
+	checkMode(t, f.Name(), 0456)
+
+	if err := f.Chmod(0123); err != nil {
+		t.Fatalf("chmod %s 0123: %s", f.Name(), err)
+	}
+	checkMode(t, f.Name(), 0123)
+}
+
+func checkSize(t *testing.T, f *File, size int64) {
+	dir, err := f.Stat()
+	if err != nil {
+		t.Fatalf("Stat %q (looking for size %d): %s", f.Name(), size, err)
+	}
+	if dir.Size() != size {
+		t.Errorf("Stat %q: size %d want %d", f.Name(), dir.Size(), size)
+	}
+}
+
+func TestFTruncate(t *testing.T) {
+	f := newFile("TestFTruncate", t)
+	defer Remove(f.Name())
+	defer f.Close()
+
+	checkSize(t, f, 0)
+	f.Write([]byte("hello, world\n"))
+	checkSize(t, f, 13)
+	f.Truncate(10)
+	checkSize(t, f, 10)
+	f.Truncate(1024)
+	checkSize(t, f, 1024)
+	f.Truncate(0)
+	checkSize(t, f, 0)
+	_, err := f.Write([]byte("surprise!"))
+	if err == nil {
+		checkSize(t, f, 13+9) // wrote at offset past where hello, world was.
+	}
+}
+
+func TestTruncate(t *testing.T) {
+	f := newFile("TestTruncate", t)
+	defer Remove(f.Name())
+	defer f.Close()
+
+	checkSize(t, f, 0)
+	f.Write([]byte("hello, world\n"))
+	checkSize(t, f, 13)
+	Truncate(f.Name(), 10)
+	checkSize(t, f, 10)
+	Truncate(f.Name(), 1024)
+	checkSize(t, f, 1024)
+	Truncate(f.Name(), 0)
+	checkSize(t, f, 0)
+	_, err := f.Write([]byte("surprise!"))
+	if err == nil {
+		checkSize(t, f, 13+9) // wrote at offset past where hello, world was.
+	}
+}
+
+// Use TempDir (via newFile) to make sure we're on a local file system,
+// so that timings are not distorted by latency and caching.
+// On NFS, timings can be off due to caching of meta-data on
+// NFS servers (Issue 848).
+func TestChtimes(t *testing.T) {
+	f := newFile("TestChtimes", t)
+	defer Remove(f.Name())
+
+	f.Write([]byte("hello, world\n"))
+	f.Close()
+
+	testChtimes(t, f.Name())
+}
+
+// Use TempDir (via newDir) to make sure we're on a local file system,
+// so that timings are not distorted by latency and caching.
+// On NFS, timings can be off due to caching of meta-data on
+// NFS servers (Issue 848).
+func TestChtimesDir(t *testing.T) {
+	name := newDir("TestChtimes", t)
+	defer RemoveAll(name)
+
+	testChtimes(t, name)
+}
+
+func testChtimes(t *testing.T, name string) {
+	st, err := Stat(name)
+	if err != nil {
+		t.Fatalf("Stat %s: %s", name, err)
+	}
+	preStat := st
+
+	// Move access and modification time back a second
+	at := Atime(preStat)
+	mt := preStat.ModTime()
+	err = Chtimes(name, at.Add(-time.Second), mt.Add(-time.Second))
+	if err != nil {
+		t.Fatalf("Chtimes %s: %s", name, err)
+	}
+
+	st, err = Stat(name)
+	if err != nil {
+		t.Fatalf("second Stat %s: %s", name, err)
+	}
+	postStat := st
+
+	/* Plan 9, NaCl:
+		Mtime is the time of the last change of content.  Similarly, atime is set whenever the
+	    contents are accessed; also, it is set whenever mtime is set.
+	*/
+	pat := Atime(postStat)
+	pmt := postStat.ModTime()
+	if !pat.Before(at) && runtime.GOOS != "plan9" && runtime.GOOS != "nacl" {
+		t.Errorf("AccessTime didn't go backwards; was=%d, after=%d", at, pat)
+	}
+
+	if !pmt.Before(mt) {
+		t.Errorf("ModTime didn't go backwards; was=%d, after=%d", mt, pmt)
+	}
+}
+
+func TestChdirAndGetwd(t *testing.T) {
+	// TODO(brainman): file.Chdir() is not implemented on windows.
+	if runtime.GOOS == "windows" {
+		return
+	}
+	fd, err := Open(".")
+	if err != nil {
+		t.Fatalf("Open .: %s", err)
+	}
+	// These are chosen carefully not to be symlinks on a Mac
+	// (unlike, say, /var, /etc), except /tmp, which we handle below.
+	dirs := []string{"/", "/usr/bin", "/tmp"}
+	// /usr/bin does not usually exist on Plan 9 or Android.
+	switch runtime.GOOS {
+	case "android":
+		dirs = []string{"/", "/system/bin"}
+	case "plan9":
+		dirs = []string{"/", "/usr"}
+	}
+	oldwd := Getenv("PWD")
+	for mode := 0; mode < 2; mode++ {
+		for _, d := range dirs {
+			if mode == 0 {
+				err = Chdir(d)
+			} else {
+				fd1, err := Open(d)
+				if err != nil {
+					t.Errorf("Open %s: %s", d, err)
+					continue
+				}
+				err = fd1.Chdir()
+				fd1.Close()
+			}
+			if d == "/tmp" {
+				Setenv("PWD", "/tmp")
+			}
+			pwd, err1 := Getwd()
+			Setenv("PWD", oldwd)
+			err2 := fd.Chdir()
+			if err2 != nil {
+				// We changed the current directory and cannot go back.
+				// Don't let the tests continue; they'll scribble
+				// all over some other directory.
+				fmt.Fprintf(Stderr, "fchdir back to dot failed: %s\n", err2)
+				Exit(1)
+			}
+			if err != nil {
+				fd.Close()
+				t.Fatalf("Chdir %s: %s", d, err)
+			}
+			if err1 != nil {
+				fd.Close()
+				t.Fatalf("Getwd in %s: %s", d, err1)
+			}
+			if pwd != d {
+				fd.Close()
+				t.Fatalf("Getwd returned %q want %q", pwd, d)
+			}
+		}
+	}
+	fd.Close()
+}
+
+func TestSeek(t *testing.T) {
+	f := newFile("TestSeek", t)
+	defer Remove(f.Name())
+	defer f.Close()
+
+	const data = "hello, world\n"
+	io.WriteString(f, data)
+
+	type test struct {
+		in     int64
+		whence int
+		out    int64
+	}
+	var tests = []test{
+		{0, 1, int64(len(data))},
+		{0, 0, 0},
+		{5, 0, 5},
+		{0, 2, int64(len(data))},
+		{0, 0, 0},
+		{-1, 2, int64(len(data)) - 1},
+		{1 << 33, 0, 1 << 33},
+		{1 << 33, 2, 1<<33 + int64(len(data))},
+	}
+	for i, tt := range tests {
+		off, err := f.Seek(tt.in, tt.whence)
+		if off != tt.out || err != nil {
+			if e, ok := err.(*PathError); ok && e.Err == syscall.EINVAL && tt.out > 1<<32 {
+				// Reiserfs rejects the big seeks.
+				// http://code.google.com/p/go/issues/detail?id=91
+				break
+			}
+			t.Errorf("#%d: Seek(%v, %v) = %v, %v want %v, nil", i, tt.in, tt.whence, off, err, tt.out)
+		}
+	}
+}
+
+type openErrorTest struct {
+	path  string
+	mode  int
+	error error
+}
+
+var openErrorTests = []openErrorTest{
+	{
+		sfdir + "/no-such-file",
+		O_RDONLY,
+		syscall.ENOENT,
+	},
+	{
+		sfdir,
+		O_WRONLY,
+		syscall.EISDIR,
+	},
+	{
+		sfdir + "/" + sfname + "/no-such-file",
+		O_WRONLY,
+		syscall.ENOTDIR,
+	},
+}
+
+func TestOpenError(t *testing.T) {
+	for _, tt := range openErrorTests {
+		f, err := OpenFile(tt.path, tt.mode, 0)
+		if err == nil {
+			t.Errorf("Open(%q, %d) succeeded", tt.path, tt.mode)
+			f.Close()
+			continue
+		}
+		perr, ok := err.(*PathError)
+		if !ok {
+			t.Errorf("Open(%q, %d) returns error of %T type; want *PathError", tt.path, tt.mode, err)
+		}
+		if perr.Err != tt.error {
+			if runtime.GOOS == "plan9" {
+				syscallErrStr := perr.Err.Error()
+				expectedErrStr := strings.Replace(tt.error.Error(), "file ", "", 1)
+				if !strings.HasSuffix(syscallErrStr, expectedErrStr) {
+					// Some Plan 9 file servers incorrectly return
+					// EACCES rather than EISDIR when a directory is
+					// opened for write.
+					if tt.error == syscall.EISDIR && strings.HasSuffix(syscallErrStr, syscall.EACCES.Error()) {
+						continue
+					}
+					t.Errorf("Open(%q, %d) = _, %q; want suffix %q", tt.path, tt.mode, syscallErrStr, expectedErrStr)
+				}
+				continue
+			}
+			if runtime.GOOS == "dragonfly" {
+				// DragonFly incorrectly returns EACCES rather
+				// EISDIR when a directory is opened for write.
+				if tt.error == syscall.EISDIR && perr.Err == syscall.EACCES {
+					continue
+				}
+			}
+			t.Errorf("Open(%q, %d) = _, %q; want %q", tt.path, tt.mode, perr.Err.Error(), tt.error.Error())
+		}
+	}
+}
+
+func TestOpenNoName(t *testing.T) {
+	f, err := Open("")
+	if err == nil {
+		t.Fatal(`Open("") succeeded`)
+		f.Close()
+	}
+}
+
+func run(t *testing.T, cmd []string) string {
+	// Run /bin/hostname and collect output.
+	r, w, err := Pipe()
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer r.Close()
+	p, err := StartProcess("/bin/hostname", []string{"hostname"}, &ProcAttr{Files: []*File{nil, w, Stderr}})
+	if err != nil {
+		t.Fatal(err)
+	}
+	w.Close()
+
+	var b bytes.Buffer
+	io.Copy(&b, r)
+	_, err = p.Wait()
+	if err != nil {
+		t.Fatalf("run hostname Wait: %v", err)
+	}
+	err = p.Kill()
+	if err == nil {
+		t.Errorf("expected an error from Kill running 'hostname'")
+	}
+	output := b.String()
+	if n := len(output); n > 0 && output[n-1] == '\n' {
+		output = output[0 : n-1]
+	}
+	if output == "" {
+		t.Fatalf("%v produced no output", cmd)
+	}
+
+	return output
+}
+
+func TestHostname(t *testing.T) {
+	// There is no other way to fetch hostname on windows, but via winapi.
+	// On Plan 9 it can be taken from #c/sysname as Hostname() does.
+	switch runtime.GOOS {
+	case "android", "nacl", "plan9", "windows":
+		t.Skipf("skipping on %s", runtime.GOOS)
+	}
+
+	// Check internal Hostname() against the output of /bin/hostname.
+	// Allow that the internal Hostname returns a Fully Qualified Domain Name
+	// and the /bin/hostname only returns the first component
+	hostname, err := Hostname()
+	if err != nil {
+		t.Fatalf("%v", err)
+	}
+	want := run(t, []string{"/bin/hostname"})
+	if hostname != want {
+		i := strings.Index(hostname, ".")
+		if i < 0 || hostname[0:i] != want {
+			t.Errorf("Hostname() = %q, want %q", hostname, want)
+		}
+	}
+}
+
+func TestReadAt(t *testing.T) {
+	f := newFile("TestReadAt", t)
+	defer Remove(f.Name())
+	defer f.Close()
+
+	const data = "hello, world\n"
+	io.WriteString(f, data)
+
+	b := make([]byte, 5)
+	n, err := f.ReadAt(b, 7)
+	if err != nil || n != len(b) {
+		t.Fatalf("ReadAt 7: %d, %v", n, err)
+	}
+	if string(b) != "world" {
+		t.Fatalf("ReadAt 7: have %q want %q", string(b), "world")
+	}
+}
+
+func TestWriteAt(t *testing.T) {
+	f := newFile("TestWriteAt", t)
+	defer Remove(f.Name())
+	defer f.Close()
+
+	const data = "hello, world\n"
+	io.WriteString(f, data)
+
+	n, err := f.WriteAt([]byte("WORLD"), 7)
+	if err != nil || n != 5 {
+		t.Fatalf("WriteAt 7: %d, %v", n, err)
+	}
+
+	b, err := ioutil.ReadFile(f.Name())
+	if err != nil {
+		t.Fatalf("ReadFile %s: %v", f.Name(), err)
+	}
+	if string(b) != "hello, WORLD\n" {
+		t.Fatalf("after write: have %q want %q", string(b), "hello, WORLD\n")
+	}
+}
+
+func writeFile(t *testing.T, fname string, flag int, text string) string {
+	f, err := OpenFile(fname, flag, 0666)
+	if err != nil {
+		t.Fatalf("Open: %v", err)
+	}
+	n, err := io.WriteString(f, text)
+	if err != nil {
+		t.Fatalf("WriteString: %d, %v", n, err)
+	}
+	f.Close()
+	data, err := ioutil.ReadFile(fname)
+	if err != nil {
+		t.Fatalf("ReadFile: %v", err)
+	}
+	return string(data)
+}
+
+func TestAppend(t *testing.T) {
+	const f = "append.txt"
+	defer Remove(f)
+	s := writeFile(t, f, O_CREATE|O_TRUNC|O_RDWR, "new")
+	if s != "new" {
+		t.Fatalf("writeFile: have %q want %q", s, "new")
+	}
+	s = writeFile(t, f, O_APPEND|O_RDWR, "|append")
+	if s != "new|append" {
+		t.Fatalf("writeFile: have %q want %q", s, "new|append")
+	}
+	s = writeFile(t, f, O_CREATE|O_APPEND|O_RDWR, "|append")
+	if s != "new|append|append" {
+		t.Fatalf("writeFile: have %q want %q", s, "new|append|append")
+	}
+	err := Remove(f)
+	if err != nil {
+		t.Fatalf("Remove: %v", err)
+	}
+	s = writeFile(t, f, O_CREATE|O_APPEND|O_RDWR, "new&append")
+	if s != "new&append" {
+		t.Fatalf("writeFile: after append have %q want %q", s, "new&append")
+	}
+	s = writeFile(t, f, O_CREATE|O_RDWR, "old")
+	if s != "old&append" {
+		t.Fatalf("writeFile: after create have %q want %q", s, "old&append")
+	}
+	s = writeFile(t, f, O_CREATE|O_TRUNC|O_RDWR, "new")
+	if s != "new" {
+		t.Fatalf("writeFile: after truncate have %q want %q", s, "new")
+	}
+}
+
+func TestStatDirWithTrailingSlash(t *testing.T) {
+	// Create new temporary directory and arrange to clean it up.
+	path, err := ioutil.TempDir("", "/_TestStatDirWithSlash_")
+	if err != nil {
+		t.Fatalf("TempDir: %s", err)
+	}
+	defer RemoveAll(path)
+
+	// Stat of path should succeed.
+	_, err = Stat(path)
+	if err != nil {
+		t.Fatalf("stat %s failed: %s", path, err)
+	}
+
+	// Stat of path+"/" should succeed too.
+	path += "/"
+	_, err = Stat(path)
+	if err != nil {
+		t.Fatalf("stat %s failed: %s", path, err)
+	}
+}
+
+func TestNilProcessStateString(t *testing.T) {
+	var ps *ProcessState
+	s := ps.String()
+	if s != "<nil>" {
+		t.Errorf("(*ProcessState)(nil).String() = %q, want %q", s, "<nil>")
+	}
+}
+
+func TestSameFile(t *testing.T) {
+	fa, err := Create("a")
+	if err != nil {
+		t.Fatalf("Create(a): %v", err)
+	}
+	defer Remove(fa.Name())
+	fa.Close()
+	fb, err := Create("b")
+	if err != nil {
+		t.Fatalf("Create(b): %v", err)
+	}
+	defer Remove(fb.Name())
+	fb.Close()
+
+	ia1, err := Stat("a")
+	if err != nil {
+		t.Fatalf("Stat(a): %v", err)
+	}
+	ia2, err := Stat("a")
+	if err != nil {
+		t.Fatalf("Stat(a): %v", err)
+	}
+	if !SameFile(ia1, ia2) {
+		t.Errorf("files should be same")
+	}
+
+	ib, err := Stat("b")
+	if err != nil {
+		t.Fatalf("Stat(b): %v", err)
+	}
+	if SameFile(ia1, ib) {
+		t.Errorf("files should be different")
+	}
+}
+
+func TestDevNullFile(t *testing.T) {
+	f, err := Open(DevNull)
+	if err != nil {
+		t.Fatalf("Open(%s): %v", DevNull, err)
+	}
+	defer f.Close()
+	fi, err := f.Stat()
+	if err != nil {
+		t.Fatalf("Stat(%s): %v", DevNull, err)
+	}
+	name := filepath.Base(DevNull)
+	if fi.Name() != name {
+		t.Fatalf("wrong file name have %v want %v", fi.Name(), name)
+	}
+	if fi.Size() != 0 {
+		t.Fatalf("wrong file size have %d want 0", fi.Size())
+	}
+}
+
+var testLargeWrite = flag.Bool("large_write", false, "run TestLargeWriteToConsole test that floods console with output")
+
+func TestLargeWriteToConsole(t *testing.T) {
+	if !*testLargeWrite {
+		t.Skip("skipping console-flooding test; enable with -large_write")
+	}
+	b := make([]byte, 32000)
+	for i := range b {
+		b[i] = '.'
+	}
+	b[len(b)-1] = '\n'
+	n, err := Stdout.Write(b)
+	if err != nil {
+		t.Fatalf("Write to os.Stdout failed: %v", err)
+	}
+	if n != len(b) {
+		t.Errorf("Write to os.Stdout should return %d; got %d", len(b), n)
+	}
+	n, err = Stderr.Write(b)
+	if err != nil {
+		t.Fatalf("Write to os.Stderr failed: %v", err)
+	}
+	if n != len(b) {
+		t.Errorf("Write to os.Stderr should return %d; got %d", len(b), n)
+	}
+}
+
+func TestStatDirModeExec(t *testing.T) {
+	const mode = 0111
+
+	path, err := ioutil.TempDir("", "go-build")
+	if err != nil {
+		t.Fatalf("Failed to create temp directory: %v", err)
+	}
+	defer RemoveAll(path)
+
+	if err := Chmod(path, 0777); err != nil {
+		t.Fatalf("Chmod %q 0777: %v", path, err)
+	}
+
+	dir, err := Stat(path)
+	if err != nil {
+		t.Fatalf("Stat %q (looking for mode %#o): %s", path, mode, err)
+	}
+	if dir.Mode()&mode != mode {
+		t.Errorf("Stat %q: mode %#o want %#o", path, dir.Mode()&mode, mode)
+	}
+}
+
+func TestReadAtEOF(t *testing.T) {
+	f := newFile("TestReadAtEOF", t)
+	defer Remove(f.Name())
+	defer f.Close()
+
+	_, err := f.ReadAt(make([]byte, 10), 0)
+	switch err {
+	case io.EOF:
+		// all good
+	case nil:
+		t.Fatalf("ReadAt succeeded")
+	default:
+		t.Fatalf("ReadAt failed: %s", err)
+	}
+}
+
+func testKillProcess(t *testing.T, processKiller func(p *Process)) {
+	switch runtime.GOOS {
+	case "android", "nacl":
+		t.Skipf("skipping on %s", runtime.GOOS)
+	}
+
+	dir, err := ioutil.TempDir("", "go-build")
+	if err != nil {
+		t.Fatalf("Failed to create temp directory: %v", err)
+	}
+	defer RemoveAll(dir)
+
+	src := filepath.Join(dir, "main.go")
+	f, err := Create(src)
+	if err != nil {
+		t.Fatalf("Failed to create %v: %v", src, err)
+	}
+	st := template.Must(template.New("source").Parse(`
+package main
+import "time"
+func main() {
+	time.Sleep(time.Second)
+}
+`))
+	err = st.Execute(f, nil)
+	if err != nil {
+		f.Close()
+		t.Fatalf("Failed to execute template: %v", err)
+	}
+	f.Close()
+
+	exe := filepath.Join(dir, "main.exe")
+	output, err := osexec.Command("go", "build", "-o", exe, src).CombinedOutput()
+	if err != nil {
+		t.Fatalf("Failed to build exe %v: %v %v", exe, err, string(output))
+	}
+
+	cmd := osexec.Command(exe)
+	err = cmd.Start()
+	if err != nil {
+		t.Fatalf("Failed to start test process: %v", err)
+	}
+	go func() {
+		time.Sleep(100 * time.Millisecond)
+		processKiller(cmd.Process)
+	}()
+	err = cmd.Wait()
+	if err == nil {
+		t.Errorf("Test process succeeded, but expected to fail")
+	}
+}
+
+func TestKillStartProcess(t *testing.T) {
+	testKillProcess(t, func(p *Process) {
+		err := p.Kill()
+		if err != nil {
+			t.Fatalf("Failed to kill test process: %v", err)
+		}
+	})
+}
+
+func TestGetppid(t *testing.T) {
+	switch runtime.GOOS {
+	case "nacl":
+		t.Skip("skipping on nacl")
+	case "plan9":
+		// TODO: golang.org/issue/8206
+		t.Skipf("skipping test on plan9; see issue 8206")
+	}
+
+	if Getenv("GO_WANT_HELPER_PROCESS") == "1" {
+		fmt.Print(Getppid())
+		Exit(0)
+	}
+
+	cmd := osexec.Command(Args[0], "-test.run=TestGetppid")
+	cmd.Env = append(Environ(), "GO_WANT_HELPER_PROCESS=1")
+
+	// verify that Getppid() from the forked process reports our process id
+	output, err := cmd.CombinedOutput()
+	if err != nil {
+		t.Fatalf("Failed to spawn child process: %v %q", err, string(output))
+	}
+
+	childPpid := string(output)
+	ourPid := fmt.Sprintf("%d", Getpid())
+	if childPpid != ourPid {
+		t.Fatalf("Child process reports parent process id '%v', expected '%v'", childPpid, ourPid)
+	}
+}
+
+func TestKillFindProcess(t *testing.T) {
+	testKillProcess(t, func(p *Process) {
+		p2, err := FindProcess(p.Pid)
+		if err != nil {
+			t.Fatalf("Failed to find test process: %v", err)
+		}
+		err = p2.Kill()
+		if err != nil {
+			t.Fatalf("Failed to kill test process: %v", err)
+		}
+	})
+}
+
+var nilFileMethodTests = []struct {
+	name string
+	f    func(*File) error
+}{
+	{"Chdir", func(f *File) error { return f.Chdir() }},
+	{"Close", func(f *File) error { return f.Close() }},
+	{"Chmod", func(f *File) error { return f.Chmod(0) }},
+	{"Chown", func(f *File) error { return f.Chown(0, 0) }},
+	{"Read", func(f *File) error { _, err := f.Read(make([]byte, 0)); return err }},
+	{"ReadAt", func(f *File) error { _, err := f.ReadAt(make([]byte, 0), 0); return err }},
+	{"Readdir", func(f *File) error { _, err := f.Readdir(1); return err }},
+	{"Readdirnames", func(f *File) error { _, err := f.Readdirnames(1); return err }},
+	{"Seek", func(f *File) error { _, err := f.Seek(0, 0); return err }},
+	{"Stat", func(f *File) error { _, err := f.Stat(); return err }},
+	{"Sync", func(f *File) error { return f.Sync() }},
+	{"Truncate", func(f *File) error { return f.Truncate(0) }},
+	{"Write", func(f *File) error { _, err := f.Write(make([]byte, 0)); return err }},
+	{"WriteAt", func(f *File) error { _, err := f.WriteAt(make([]byte, 0), 0); return err }},
+	{"WriteString", func(f *File) error { _, err := f.WriteString(""); return err }},
+}
+
+// Test that all File methods give ErrInvalid if the receiver is nil.
+func TestNilFileMethods(t *testing.T) {
+	for _, tt := range nilFileMethodTests {
+		var file *File
+		got := tt.f(file)
+		if got != ErrInvalid {
+			t.Errorf("%v should fail when f is nil; got %v", tt.name, got)
+		}
+	}
+}
+
+func mkdirTree(t *testing.T, root string, level, max int) {
+	if level >= max {
+		return
+	}
+	level++
+	for i := 'a'; i < 'c'; i++ {
+		dir := filepath.Join(root, string(i))
+		if err := Mkdir(dir, 0700); err != nil {
+			t.Fatal(err)
+		}
+		mkdirTree(t, dir, level, max)
+	}
+}
+
+// Test that simultaneous RemoveAll do not report an error.
+// As long as it gets removed, we should be happy.
+func TestRemoveAllRace(t *testing.T) {
+	if runtime.GOOS == "windows" {
+		// Windows has very strict rules about things like
+		// removing directories while someone else has
+		// them open. The racing doesn't work out nicely
+		// like it does on Unix.
+		t.Skip("skipping on windows")
+	}
+
+	n := runtime.GOMAXPROCS(16)
+	defer runtime.GOMAXPROCS(n)
+	root, err := ioutil.TempDir("", "issue")
+	if err != nil {
+		t.Fatal(err)
+	}
+	mkdirTree(t, root, 1, 6)
+	hold := make(chan struct{})
+	var wg sync.WaitGroup
+	for i := 0; i < 4; i++ {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			<-hold
+			err := RemoveAll(root)
+			if err != nil {
+				t.Errorf("unexpected error: %T, %q", err, err)
+			}
+		}()
+	}
+	close(hold) // let workers race to remove root
+	wg.Wait()
+}