pkg syscall, type RawConn interface, Read(func(uintptr) bool) error
pkg syscall, type RawConn interface, Write(func(uintptr) bool) error
pkg testing, method (*B) Helper()
pkg testing, method (*T) Helper()
pkg testing, type TB interface, Helper()
pkg time, method (Duration) Round(Duration) Duration

	os.Setenv("GO_ADDR2LINETEST_IS_ADDR2LINE", "1") // Set for subprocesses to inherit.
	os.Exit(m.Run())
}

// addr2linePath returns the path to the "addr2line" binary to run.
func addr2linePath(t testing.TB) string {
	t.Helper()
	testenv.MustHaveExec(t)

	addr2linePathOnce.Do(func() {
		addr2lineExePath, addr2linePathErr = os.Executable()
	})
	if addr2linePathErr != nil {
		t.Fatal(addr2linePathErr)
	}
	return addr2lineExePath
}

// The Header.Size determines how many bytes can be written for the next file.
// If the current file is not fully written, then this returns an error.
// This implicitly flushes any padding necessary before writing the header.
func (tw *Writer) WriteHeader(hdr *Header) error {
	if err := tw.Flush(); err != nil {
		return err
	}
	tw.hdr = *hdr // Shallow copy of Header

	}{
		{"readme.txt", "This archive contains some text files."},
		{"gopher.txt", "Gopher names:\nGeorge\nGeoffrey\nGonzo"},
		{"todo.txt", "Get animal handling license."},
	}
	for _, file := range files {
		hdr := &tar.Header{
			Name: file.Name,
			Mode: 0600,
			Size: int64(len(file.Body)),
		}
		if err := tw.WriteHeader(hdr); err != nil {
			log.Fatal(err)
		}
		if _, err := tw.Write([]byte(file.Body)); err != nil {

	}
}

func testValidHeader(h *FileHeader, t *testing.T) {
	var buf bytes.Buffer
	z := NewWriter(&buf)

	f, err := z.CreateHeader(h)
	if err != nil {
		t.Fatalf("error creating header: %v", err)
	}
	if _, err := f.Write([]byte("hi")); err != nil {
		t.Fatalf("error writing content: %v", err)
	}
	if err := z.Close(); err != nil {
		t.Fatalf("error closing zip writer: %v", err)
	}

pkg archive/tar, const TypeSymlink = 50
pkg archive/tar, const TypeXGlobalHeader = 103
pkg archive/tar, const TypeXHeader = 120
pkg archive/tar, func FileInfoHeader(os.FileInfo, string) (*Header, error)
pkg archive/tar, method (*Header) FileInfo() os.FileInfo
pkg archive/zip, const Deflate = 8
pkg archive/zip, const Store = 0
pkg archive/zip, type FileHeader struct, CompressedSize64 uint64

// The downside is that renaming uname or gname by the OS never takes effect.
var userMap, groupMap sync.Map // map[int]string

func statUnix(fi fs.FileInfo, h *Header, doNameLookups bool) error {
	sys, ok := fi.Sys().(*syscall.Stat_t)
	if !ok {
		return nil
	}
	h.Uid = int(sys.Uid)
	h.Gid = int(sys.Gid)
	if doNameLookups {
		// Best effort at populating Uname and Gname.

pkg syscall (freebsd-arm), type InterfaceAnnounceMessage struct
pkg syscall (freebsd-arm), type InterfaceAnnounceMessage struct, Header IfAnnounceMsghdr
pkg syscall (freebsd-arm), type InterfaceMessage struct
pkg syscall (freebsd-arm), type InterfaceMessage struct, Data []uint8
pkg syscall (freebsd-arm), type InterfaceMessage struct, Header IfMsghdr

	func C.GoBytes(unsafe.Pointer, C.int) []byte

As a special case, C.malloc does not call the C library malloc directly
but instead calls a Go helper function that wraps the C library malloc
but guarantees never to return nil. If C's malloc indicates out of memory,
the helper function crashes the program, like when Go itself runs out
of memory. Because C.malloc cannot fail, it has no two-result form
that returns errno.

}

func (w *teststringwriter) WriteString(s string) (int, error) {
	w.writeString += s
	return len(s), nil
}

func (w *teststringwriter) check(t *testing.T, write, writeString string) {
	t.Helper()
	if w.write != write {
		t.Errorf("write: expected %q, got %q", write, w.write)
	}
	if w.writeString != writeString {
		t.Errorf("writeString: expected %q, got %q", writeString, w.writeString)
	}
}