patch: os.File

This commit is contained in:
xushiwei
2024-06-27 02:28:18 +08:00
parent 369581976a
commit 2165941026
6 changed files with 474 additions and 133 deletions

View File

@@ -213,8 +213,12 @@ Here are the Go packages that can be imported correctly:
* [sync/atomic](https://pkg.go.dev/sync/atomic)
* [sync](https://pkg.go.dev/sync) (partially)
* [syscall](https://pkg.go.dev/syscall) (partially)
* [errors](https://pkg.go.dev/errors) (partially)
* [io](https://pkg.go.dev/io) (partially)
* [io/fs](https://pkg.go.dev/io/fs) (partially)
* [os](https://pkg.go.dev/os) (partially)
* [reflect](https://pkg.go.dev/reflect) (partially)
* [time](https://pkg.go.dev/time) (partially)
## Dependencies

View File

@@ -7,9 +7,6 @@ package fmt
import (
"io"
"os"
"reflect"
"strconv"
"sync"
"unicode/utf8"
)
@@ -32,6 +29,7 @@ const (
invReflectString = "<invalid reflect.Value>"
)
/* TODO(xsw):
// State represents the printer state passed to custom formatters.
// It provides access to the io.Writer interface plus information about
// the flags and options for the operand's format specifier.
@@ -53,6 +51,7 @@ type State interface {
type Formatter interface {
Format(f State, verb rune)
}
*/
// Stringer is implemented by any value that has a String method,
// which defines the “native” format for that value.
@@ -71,6 +70,7 @@ type GoStringer interface {
GoString() string
}
/* TODO(xsw):
// FormatString returns a string representing the fully qualified formatting
// directive captured by the State, followed by the argument verb. (State does not
// itself contain the verb.) The result has a leading percent sign followed by any
@@ -95,6 +95,7 @@ func FormatString(state State, verb rune) string {
b = utf8.AppendRune(b, verb)
return string(b)
}
*/
// Use simple []byte instead of bytes.Buffer to avoid large dependency.
type buffer []byte
@@ -123,7 +124,8 @@ type pp struct {
arg any
// value is used instead of arg for reflect values.
value reflect.Value
// TODO(xsw):
// value reflect.Value
// fmt is used to format basic items such as integers or strings.
fmt fmt
@@ -142,13 +144,17 @@ type pp struct {
wrappedErrs []int
}
/* TODO(xsw):
var ppFree = sync.Pool{
New: func() any { return new(pp) },
}
*/
// newPrinter allocates a new pp struct or grabs a cached one.
func newPrinter() *pp {
p := ppFree.Get().(*pp)
// TODO(xsw):
// p := ppFree.Get().(*pp)
p := &pp{}
p.panicking = false
p.erroring = false
p.wrapErrs = false
@@ -175,9 +181,11 @@ func (p *pp) free() {
}
p.arg = nil
p.value = reflect.Value{}
// TODO(xsw):
// p.value = reflect.Value{}
p.wrappedErrs = p.wrappedErrs[:0]
ppFree.Put(p)
// TODO(xsw):
// ppFree.Put(p)
}
func (p *pp) Width() (wid int, ok bool) { return p.fmt.wid, p.fmt.widPresent }
@@ -214,6 +222,7 @@ func (p *pp) WriteString(s string) (ret int, err error) {
return len(s), nil
}
/* TODO(xsw):
// These routines end in 'f' and take a format string.
// Fprintf formats according to a format specifier and writes to w.
@@ -250,6 +259,7 @@ func Appendf(b []byte, format string, a ...any) []byte {
p.free()
return b
}
*/
// These routines do not take a format string
@@ -334,6 +344,7 @@ func Appendln(b []byte, a ...any) []byte {
return b
}
/* TODO(xsw):
// getField gets the i'th field of the struct value.
// If the field is itself is an interface, return a value for
// the thing inside the interface, not the interface itself.
@@ -376,28 +387,33 @@ func (p *pp) unknownType(v reflect.Value) {
p.buf.writeString(v.Type().String())
p.buf.writeByte('?')
}
*/
func (p *pp) badVerb(verb rune) {
p.erroring = true
p.buf.writeString(percentBangString)
p.buf.writeRune(verb)
p.buf.writeByte('(')
switch {
case p.arg != nil:
p.buf.writeString(reflect.TypeOf(p.arg).String())
p.buf.writeByte('=')
p.printArg(p.arg, 'v')
case p.value.IsValid():
p.buf.writeString(p.value.Type().String())
p.buf.writeByte('=')
p.printValue(p.value, 'v', 0)
default:
p.buf.writeString(nilAngleString)
}
p.buf.writeByte(')')
p.erroring = false
/*
p.erroring = true
p.buf.writeString(percentBangString)
p.buf.writeRune(verb)
p.buf.writeByte('(')
switch {
case p.arg != nil:
p.buf.writeString(reflect.TypeOf(p.arg).String())
p.buf.writeByte('=')
p.printArg(p.arg, 'v')
case p.value.IsValid():
p.buf.writeString(p.value.Type().String())
p.buf.writeByte('=')
p.printValue(p.value, 'v', 0)
default:
p.buf.writeString(nilAngleString)
}
p.buf.writeByte(')')
p.erroring = false
*/
panic("todo: fmt.(*pp).badVerb")
}
/* TODO(xsw):
func (p *pp) fmtBool(v bool, verb rune) {
switch verb {
case 't', 'v':
@@ -483,6 +499,7 @@ func (p *pp) fmtComplex(v complex128, size int, verb rune) {
p.badVerb(verb)
}
}
*/
func (p *pp) fmtString(v string, verb rune) {
switch verb {
@@ -505,6 +522,7 @@ func (p *pp) fmtString(v string, verb rune) {
}
}
/* TODO(xsw):
func (p *pp) fmtBytes(v []byte, verb rune, typeString string) {
switch verb {
case 'v', 'd':
@@ -541,10 +559,12 @@ func (p *pp) fmtBytes(v []byte, verb rune, typeString string) {
case 'q':
p.fmt.fmtQ(string(v))
default:
p.printValue(reflect.ValueOf(v), verb, 0)
// p.printValue(reflect.ValueOf(v), verb, 0)
panic("todo: fmt.(*pp).fmtBytes")
}
}
/* TODO(xsw):
func (p *pp) fmtPointer(value reflect.Value, verb rune) {
var u uintptr
switch value.Kind() {
@@ -676,10 +696,12 @@ func (p *pp) handleMethods(verb rune) (handled bool) {
}
return false
}
*/
func (p *pp) printArg(arg any, verb rune) {
p.arg = arg
p.value = reflect.Value{}
// TODO(xsw):
// p.value = reflect.Value{}
if arg == nil {
switch verb {
@@ -695,49 +717,54 @@ func (p *pp) printArg(arg any, verb rune) {
// %T (the value's type) and %p (its address) are special; we always do them first.
switch verb {
case 'T':
p.fmt.fmtS(reflect.TypeOf(arg).String())
return
// p.fmt.fmtS(reflect.TypeOf(arg).String())
// return
panic("todo: fmt.(*pp).printArg")
case 'p':
p.fmtPointer(reflect.ValueOf(arg), 'p')
return
// p.fmtPointer(reflect.ValueOf(arg), 'p')
// return
panic("todo: fmt.(*pp).printArg")
}
// Some types can be done without reflection.
switch f := arg.(type) {
case bool:
p.fmtBool(f, verb)
case float32:
p.fmtFloat(float64(f), 32, verb)
case float64:
p.fmtFloat(f, 64, verb)
case complex64:
p.fmtComplex(complex128(f), 64, verb)
case complex128:
p.fmtComplex(f, 128, verb)
case int:
p.fmtInteger(uint64(f), signed, verb)
case int8:
p.fmtInteger(uint64(f), signed, verb)
case int16:
p.fmtInteger(uint64(f), signed, verb)
case int32:
p.fmtInteger(uint64(f), signed, verb)
case int64:
p.fmtInteger(uint64(f), signed, verb)
case uint:
p.fmtInteger(uint64(f), unsigned, verb)
case uint8:
p.fmtInteger(uint64(f), unsigned, verb)
case uint16:
p.fmtInteger(uint64(f), unsigned, verb)
case uint32:
p.fmtInteger(uint64(f), unsigned, verb)
case uint64:
p.fmtInteger(f, unsigned, verb)
case uintptr:
p.fmtInteger(uint64(f), unsigned, verb)
/*
case bool:
p.fmtBool(f, verb)
case float32:
p.fmtFloat(float64(f), 32, verb)
case float64:
p.fmtFloat(f, 64, verb)
case complex64:
p.fmtComplex(complex128(f), 64, verb)
case complex128:
p.fmtComplex(f, 128, verb)
case int:
p.fmtInteger(uint64(f), signed, verb)
case int8:
p.fmtInteger(uint64(f), signed, verb)
case int16:
p.fmtInteger(uint64(f), signed, verb)
case int32:
p.fmtInteger(uint64(f), signed, verb)
case int64:
p.fmtInteger(uint64(f), signed, verb)
case uint:
p.fmtInteger(uint64(f), unsigned, verb)
case uint8:
p.fmtInteger(uint64(f), unsigned, verb)
case uint16:
p.fmtInteger(uint64(f), unsigned, verb)
case uint32:
p.fmtInteger(uint64(f), unsigned, verb)
case uint64:
p.fmtInteger(f, unsigned, verb)
case uintptr:
p.fmtInteger(uint64(f), unsigned, verb)
*/
case string:
p.fmtString(f, verb)
/* TODO(xsw):
case []byte:
p.fmtBytes(f, verb, "[]byte")
case reflect.Value:
@@ -750,16 +777,21 @@ func (p *pp) printArg(arg any, verb rune) {
}
}
p.printValue(f, verb, 0)
*/
default:
// If the type is not simple, it might have methods.
if !p.handleMethods(verb) {
// Need to use reflection, since the type had no
// interface methods that could be used for formatting.
p.printValue(reflect.ValueOf(f), verb, 0)
}
/*
// If the type is not simple, it might have methods.
if !p.handleMethods(verb) {
// Need to use reflection, since the type had no
// interface methods that could be used for formatting.
p.printValue(reflect.ValueOf(f), verb, 0)
}
*/
panic("todo: fmt.(*pp).printArg")
}
}
/*
// printValue is similar to printArg but starts with a reflect value, not an interface{} value.
// It does not handle 'p' and 'T' verbs because these should have been already handled by printArg.
func (p *pp) printValue(value reflect.Value, verb rune, depth int) {
@@ -802,37 +834,34 @@ func (p *pp) printValue(value reflect.Value, verb rune, depth int) {
case reflect.String:
p.fmtString(f.String(), verb)
case reflect.Map:
/*
if p.fmt.sharpV {
p.buf.writeString(f.Type().String())
if f.IsNil() {
p.buf.writeString(nilParenString)
return
if p.fmt.sharpV {
p.buf.writeString(f.Type().String())
if f.IsNil() {
p.buf.writeString(nilParenString)
return
}
p.buf.writeByte('{')
} else {
p.buf.writeString(mapString)
}
sorted := fmtsort.Sort(f)
for i, key := range sorted.Key {
if i > 0 {
if p.fmt.sharpV {
p.buf.writeString(commaSpaceString)
} else {
p.buf.writeByte(' ')
}
p.buf.writeByte('{')
} else {
p.buf.writeString(mapString)
}
sorted := fmtsort.Sort(f)
for i, key := range sorted.Key {
if i > 0 {
if p.fmt.sharpV {
p.buf.writeString(commaSpaceString)
} else {
p.buf.writeByte(' ')
}
}
p.printValue(key, verb, depth+1)
p.buf.writeByte(':')
p.printValue(sorted.Value[i], verb, depth+1)
}
if p.fmt.sharpV {
p.buf.writeByte('}')
} else {
p.buf.writeByte(']')
}
*/
panic("todo")
p.printValue(key, verb, depth+1)
p.buf.writeByte(':')
p.printValue(sorted.Value[i], verb, depth+1)
}
if p.fmt.sharpV {
p.buf.writeByte('}')
} else {
p.buf.writeByte(']')
}
case reflect.Struct:
if p.fmt.sharpV {
p.buf.writeString(f.Type().String())
@@ -934,6 +963,7 @@ func (p *pp) printValue(value reflect.Value, verb rune, depth int) {
}
}
/* TODO(xsw):
// intFromArg gets the argNumth element of a. On return, isInt reports whether the argument has integer type.
func intFromArg(a []any, argNum int) (num int, isInt bool, newArgNum int) {
newArgNum = argNum
@@ -1201,18 +1231,22 @@ formatLoop:
p.buf.writeByte(')')
}
}
*/
func (p *pp) doPrint(a []any) {
prevString := false
for argNum, arg := range a {
isString := arg != nil && reflect.TypeOf(arg).Kind() == reflect.String
// Add a space between two non-string arguments.
if argNum > 0 && !isString && !prevString {
p.buf.writeByte(' ')
/*
prevString := false
for argNum, arg := range a {
isString := arg != nil && reflect.TypeOf(arg).Kind() == reflect.String
// Add a space between two non-string arguments.
if argNum > 0 && !isString && !prevString {
p.buf.writeByte(' ')
}
p.printArg(arg, 'v')
prevString = isString
}
p.printArg(arg, 'v')
prevString = isString
}
*/
panic("todo: fmt.(*pp).doPrint")
}
// doPrintln is like doPrint but always adds a space between arguments

View File

@@ -8,6 +8,7 @@ import (
"errors"
"io"
"syscall"
"time"
)
// Name returns the name of the file as presented to Open.
@@ -172,36 +173,42 @@ func (f *File) WriteAt(b []byte, off int64) (n int, err error) {
}
return
*/
panic("todo")
panic("todo: os.(*File).WriteAt")
}
/*
// Seek sets the offset for the next Read or Write on file to offset, interpreted
// according to whence: 0 means relative to the origin of the file, 1 means
// relative to the current offset, and 2 means relative to the end.
// It returns the new offset and an error, if any.
// The behavior of Seek on a file opened with O_APPEND is not specified.
func (f *File) Seek(offset int64, whence int) (ret int64, err error) {
if err := f.checkValid("seek"); err != nil {
return 0, err
}
r, e := f.seek(offset, whence)
if e == nil && f.dirinfo != nil && r != 0 {
e = syscall.EISDIR
}
if e != nil {
return 0, f.wrapErr("seek", e)
}
return r, nil
/*
if err := f.checkValid("seek"); err != nil {
return 0, err
}
r, e := f.seek(offset, whence)
if e == nil && f.dirinfo != nil && r != 0 {
e = syscall.EISDIR
}
if e != nil {
return 0, f.wrapErr("seek", e)
}
return r, nil
*/
panic("todo: os.(*File).Seek")
}
// WriteString is like Write, but writes the contents of string s rather than
// a slice of bytes.
func (f *File) WriteString(s string) (n int, err error) {
b := unsafe.Slice(unsafe.StringData(s), len(s))
return f.Write(b)
/*
b := unsafe.Slice(unsafe.StringData(s), len(s))
return f.Write(b)
*/
panic("todo: os.(*File).WriteString")
}
/*
// setStickyBit adds ModeSticky to the permission bits of path, non atomic.
func setStickyBit(name string) error {
fi, err := Stat(name)
@@ -293,6 +300,7 @@ func (f *File) wrapErr(op string, err error) error {
func TempDir() string {
return tempDir()
}
*/
// Chmod changes the mode of the file to mode.
// If there is an error, it will be of type *PathError.
@@ -347,12 +355,16 @@ func (f *File) SetWriteDeadline(t time.Time) error {
// SyscallConn returns a raw file.
// This implements the syscall.Conn interface.
func (f *File) SyscallConn() (syscall.RawConn, error) {
if err := f.checkValid("SyscallConn"); err != nil {
return nil, err
}
return newRawConn(f)
/*
if err := f.checkValid("SyscallConn"); err != nil {
return nil, err
}
return newRawConn(f)
*/
panic("todo: os.(*File).SyscallConn")
}
/* TODO(xsw):
// DirFS returns a file system (an fs.FS) for the tree of files rooted at the directory dir.
//
// Note that DirFS("/prefix") only guarantees that the Open calls it makes to the

View File

@@ -0,0 +1,243 @@
// 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.
//go:build unix || (js && wasm) || wasip1 || windows
package os
import (
"syscall"
"time"
)
// Close closes the File, rendering it unusable for I/O.
// On files that support SetDeadline, any pending I/O operations will
// be canceled and return immediately with an ErrClosed error.
// Close will return an error if it has already been called.
func (f *File) Close() error {
/*
if f == nil {
return ErrInvalid
}
return f.file.close()
*/
panic("todo: os.(*File).Close")
}
// pread reads len(b) bytes from the File starting at byte offset off.
// It returns the number of bytes read and the error, if any.
// EOF is signaled by a zero count with err set to nil.
func (f *File) pread(b []byte, off int64) (n int, err error) {
/*
n, err = f.pfd.Pread(b, off)
runtime.KeepAlive(f)
return n, err
*/
panic("todo: os.(*File).pread")
}
// pwrite writes len(b) bytes to the File starting at byte offset off.
// It returns the number of bytes written and an error, if any.
func (f *File) pwrite(b []byte, off int64) (n int, err error) {
/*
n, err = f.pfd.Pwrite(b, off)
runtime.KeepAlive(f)
return n, err
*/
panic("todo: os.(*File).pwrite")
}
/*
// syscallMode returns the syscall-specific mode bits from Go's portable mode bits.
func syscallMode(i FileMode) (o uint32) {
o |= uint32(i.Perm())
if i&ModeSetuid != 0 {
o |= syscall.S_ISUID
}
if i&ModeSetgid != 0 {
o |= syscall.S_ISGID
}
if i&ModeSticky != 0 {
o |= syscall.S_ISVTX
}
// No mapping for Go's ModeTemporary (plan9 only).
return
}
// See docs in file.go:Chmod.
func chmod(name string, mode FileMode) error {
longName := fixLongPath(name)
e := ignoringEINTR(func() error {
return syscall.Chmod(longName, syscallMode(mode))
})
if e != nil {
return &PathError{Op: "chmod", Path: name, Err: e}
}
return nil
}
*/
// See docs in file.go:(*File).Chmod.
func (f *File) chmod(mode FileMode) error {
/*
if err := f.checkValid("chmod"); err != nil {
return err
}
if e := f.pfd.Fchmod(syscallMode(mode)); e != nil {
return f.wrapErr("chmod", e)
}
return nil
*/
panic("todo: os.(*File).chmod")
}
// Chown changes the numeric uid and gid of the named file.
// If there is an error, it will be of type *PathError.
//
// On Windows, it always returns the syscall.EWINDOWS error, wrapped
// in *PathError.
func (f *File) Chown(uid, gid int) error {
/*
if err := f.checkValid("chown"); err != nil {
return err
}
if e := f.pfd.Fchown(uid, gid); e != nil {
return f.wrapErr("chown", e)
}
return nil
*/
panic("todo: os.(*File).Chown")
}
// Truncate changes the size of the file.
// It does not change the I/O offset.
// If there is an error, it will be of type *PathError.
func (f *File) Truncate(size int64) error {
/*
if err := f.checkValid("truncate"); err != nil {
return err
}
if e := f.pfd.Ftruncate(size); e != nil {
return f.wrapErr("truncate", e)
}
return nil
*/
panic("todo: os.(*File).Truncate")
}
// Sync commits the current contents of the file to stable storage.
// Typically, this means flushing the file system's in-memory copy
// of recently written data to disk.
func (f *File) Sync() error {
/*
if err := f.checkValid("sync"); err != nil {
return err
}
if e := f.pfd.Fsync(); e != nil {
return f.wrapErr("sync", e)
}
return nil
*/
panic("todo: os.(*File).Sync")
}
/*
// Chtimes changes the access and modification times of the named
// file, similar to the Unix utime() or utimes() functions.
// A zero time.Time value will leave the corresponding file time unchanged.
//
// The underlying filesystem may truncate or round the values to a
// less precise time unit.
// If there is an error, it will be of type *PathError.
func Chtimes(name string, atime time.Time, mtime time.Time) error {
var utimes [2]syscall.Timespec
set := func(i int, t time.Time) {
if t.IsZero() {
utimes[i] = syscall.Timespec{Sec: _UTIME_OMIT, Nsec: _UTIME_OMIT}
} else {
utimes[i] = syscall.NsecToTimespec(t.UnixNano())
}
}
set(0, atime)
set(1, mtime)
if e := syscall.UtimesNano(fixLongPath(name), utimes[0:]); e != nil {
return &PathError{Op: "chtimes", Path: name, Err: e}
}
return nil
}
*/
// Chdir changes the current working directory to the file,
// which must be a directory.
// If there is an error, it will be of type *PathError.
func (f *File) Chdir() error {
/*
if err := f.checkValid("chdir"); err != nil {
return err
}
if e := f.pfd.Fchdir(); e != nil {
return f.wrapErr("chdir", e)
}
return nil
*/
panic("todo: os.(*File).Chdir")
}
// setDeadline sets the read and write deadline.
func (f *File) setDeadline(t time.Time) error {
/*
if err := f.checkValid("SetDeadline"); err != nil {
return err
}
return f.pfd.SetDeadline(t)
*/
panic("todo: os.(*File).setDeadline")
}
// setReadDeadline sets the read deadline.
func (f *File) setReadDeadline(t time.Time) error {
/*
if err := f.checkValid("SetReadDeadline"); err != nil {
return err
}
return f.pfd.SetReadDeadline(t)
*/
panic("todo: os.(*File).setReadDeadline")
}
// setWriteDeadline sets the write deadline.
func (f *File) setWriteDeadline(t time.Time) error {
/*
if err := f.checkValid("SetWriteDeadline"); err != nil {
return err
}
return f.pfd.SetWriteDeadline(t)
*/
panic("todo: os.(*File).setWriteDeadline")
}
// checkValid checks whether f is valid for use.
// If not, it returns an appropriate error, perhaps incorporating the operation name op.
func (f *File) checkValid(op string) error {
if f == nil {
return ErrInvalid
}
return nil
}
// ignoringEINTR makes a function call and repeats it if it returns an
// EINTR error. This appears to be required even though we install all
// signal handlers with SA_RESTART: see #22838, #38033, #38836, #40846.
// Also #20400 and #36644 are issues in which a signal handler is
// installed without setting SA_RESTART. None of these are the common case,
// but there are enough of them that it seems that we can't avoid
// an EINTR loop.
func ignoringEINTR(fn func() error) error {
for {
err := fn()
if err != syscall.EINTR {
return err
}
}
}

View File

@@ -120,6 +120,25 @@ func Chown(name string, uid, gid int) error {
return toPathErr("chown", name, ret)
}
/* TODO(xsw):
// Chown changes the numeric uid and gid of the named file.
// If the file is a symbolic link, it changes the uid and gid of the link's target.
// A uid or gid of -1 means to not change that value.
// If there is an error, it will be of type *PathError.
//
// On Windows or Plan 9, Chown always returns the syscall.EWINDOWS or
// EPLAN9 error, wrapped in *PathError.
func Chown(name string, uid, gid int) error {
e := ignoringEINTR(func() error {
return syscall.Chown(name, uid, gid)
})
if e != nil {
return &PathError{Op: "chown", Path: name, Err: e}
}
return nil
}
*/
// TODO(xsw):
// func Chtimes(name string, atime time.Time, mtime time.Time) error
@@ -195,6 +214,24 @@ func Lchown(name string, uid, gid int) error {
return toPathErr("lchown", name, ret)
}
/* TODO(xsw):
// Lchown changes the numeric uid and gid of the named file.
// If the file is a symbolic link, it changes the uid and gid of the link itself.
// If there is an error, it will be of type *PathError.
//
// On Windows, it always returns the syscall.EWINDOWS error, wrapped
// in *PathError.
func Lchown(name string, uid, gid int) error {
e := ignoringEINTR(func() error {
return syscall.Lchown(name, uid, gid)
})
if e != nil {
return &PathError{Op: "lchown", Path: name, Err: e}
}
return nil
}
*/
func Link(oldname, newname string) error {
ret := os.Link(c.AllocaCStr(oldname), c.AllocaCStr(newname))
if ret == 0 {

View File

@@ -47,6 +47,16 @@ func (f *File) write(b []byte) (int, error) {
return 0, syscall.Errno(os.Errno)
}
/* TODO(xsw):
// write writes len(b) bytes to the File.
// It returns the number of bytes written and an error, if any.
func (f *File) write(b []byte) (n int, err error) {
n, err = f.pfd.Write(b)
runtime.KeepAlive(f)
return n, err
}
*/
// read reads up to len(b) bytes from the File.
// It returns the number of bytes read and an error, if any.
func (f *File) read(b []byte) (int, error) {
@@ -60,14 +70,15 @@ func (f *File) read(b []byte) (int, error) {
return 0, syscall.Errno(os.Errno)
}
// checkValid checks whether f is valid for use.
// If not, it returns an appropriate error, perhaps incorporating the operation name op.
func (f *File) checkValid(op string) error {
if f == nil {
return ErrInvalid
}
return nil
/* TODO(xsw):
// read reads up to len(b) bytes from the File.
// It returns the number of bytes read and an error, if any.
func (f *File) read(b []byte) (n int, err error) {
n, err = f.pfd.Read(b)
runtime.KeepAlive(f)
return n, err
}
*/
// A FileInfo describes a file and is returned by Stat and Lstat.
type FileInfo = fs.FileInfo