// manipulate already-open files, IsLocked is still meaningful: os.OpenFile
// itself may return errors that indicate that a file with the ModeExclusive bit
// set is already open.
func isLocked(err error) bool {
	s := err.Error()

	for _, frag := range lockedErrStrings {
		if strings.Contains(s, frag) {
			return true
		}
	}

	return false
}

func openFile(name string, flag int, perm fs.FileMode) (*os.File, error) {

// flags and shouldn't be considered as replacement
// for os.OpenFile().
func LockedOpenFile(path string, flag int, perm os.FileMode) (*LockedFile, error) {
	return lockedOpenFile(path, flag, perm, syscall.F_SETLKW)
}

// Open - Call os.OpenFile
func Open(path string, flag int, perm os.FileMode) (*os.File, error) {
	return os.OpenFile(path, flag, perm)

}

// Open will call os.Open to return the file.
func (RealOS) Open(name string) (*os.File, error) {
	return os.Open(name)
}

// OpenFile will call os.OpenFile to return the file.
func (RealOS) OpenFile(name string, flag int, perm os.FileMode) (*os.File, error) {
	return os.OpenFile(name, flag, perm)
}

// Rename will call os.Rename to rename a file.
func (RealOS) Rename(oldpath, newpath string) error {

)

func openFile(name string, flag int, perm fs.FileMode) (*os.File, error) {
	// On BSD systems, we could add the O_SHLOCK or O_EXLOCK flag to the OpenFile
	// call instead of locking separately, but we have to support separate locking
	// calls for Linux and Windows anyway, so it's simpler to use that approach
	// consistently.

	f, err := os.OpenFile(name, flag&^os.O_TRUNC, perm)
	if err != nil {

	return RenameSys(src, dst)
}

// OpenFile captures time taken to call os.OpenFile
func OpenFile(name string, flag int, perm os.FileMode) (f *os.File, err error) {
	switch flag & writeMode {
	case writeMode:
		defer updateOSMetrics(osMetricOpenFileW, name)(err)
	default:
		defer updateOSMetrics(osMetricOpenFileR, name)(err)
	}
	return os.OpenFile(name, flag, perm)
}

		if err := syscall.Mkfifo(name, 0o600); err != nil {
			t.Fatal(err)
		}
		// The problem only occurs if we use O_NONBLOCK here.
		rd, err := os.OpenFile(name, os.O_RDONLY|syscall.O_NONBLOCK, 0o600)
		if err != nil {
			t.Fatal(err)
		}
		wr, err := os.OpenFile(name, os.O_WRONLY|syscall.O_NONBLOCK, 0o600)
		if err != nil {
			t.Fatal(err)
		}
		const msg = "message"

	"testing"
)

func TestLookPathUnixEmptyPath(t *testing.T) {
	// Not parallel: uses Chdir and Setenv.

	tmp := t.TempDir()
	chdir(t, tmp)

	f, err := os.OpenFile("exec_me", os.O_CREATE|os.O_EXCL, 0700)
	if err != nil {
		t.Fatal("OpenFile failed: ", err)
	}
	err = f.Close()
	if err != nil {
		t.Fatal("Close failed: ", err)
	}

	t.Setenv("PATH", "")

	path, err := exec.LookPath("exec_me")

	}
	ofile, ok := file.(*openFile)
	if !ok {
		return nil, &fs.PathError{Op: "read", Path: name, Err: errors.New("is a directory")}
	}
	return []byte(ofile.f.data), nil
}

// An openFile is a regular file open for reading.
type openFile struct {
	f      *file // the file itself
	offset int64 // current read offset
}

var (
	_ io.Seeker   = (*openFile)(nil)
	_ io.ReaderAt = (*openFile)(nil)

	certPath := filepath.Join(tmpdir, constants.APIServerCertName)
	certFile, err := os.OpenFile(certPath, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0666)
	if err != nil {
		t.Fatalf("Failed to create cert file %s: %v", certPath, err)
	}
	certFile.Close()

	keyPath := filepath.Join(tmpdir, constants.APIServerKeyName)
	keyFile, err := os.OpenFile(keyPath, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0666)
	if err != nil {

import (
	"io/fs"
	"os"
)

// hasWritePerm reports whether the current user has permission to write to the
// file with the given info.
func hasWritePerm(path string, _ fs.FileInfo) bool {
	if f, err := os.OpenFile(path, os.O_WRONLY, 0); err == nil {
		f.Close()
		return true
	}
	return false