| // 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 |
| |
| import ( |
| "io" |
| "runtime" |
| "sync" |
| "syscall" |
| "unicode/utf16" |
| "unicode/utf8" |
| "unsafe" |
| ) |
| |
| // File represents an open file descriptor. |
| type File struct { |
| *file |
| } |
| |
| // file is the real representation of *File. |
| // The extra level of indirection ensures that no clients of os |
| // can overwrite this data, which could cause the finalizer |
| // to close the wrong file descriptor. |
| type file struct { |
| fd syscall.Handle |
| name string |
| dirinfo *dirInfo // nil unless directory being read |
| l sync.Mutex // used to implement windows pread/pwrite |
| |
| // only for console io |
| isConsole bool |
| lastbits []byte // first few bytes of the last incomplete rune in last write |
| readbuf []rune // input console buffer |
| } |
| |
| // Fd returns the Windows handle referencing the open file. |
| func (file *File) Fd() uintptr { |
| if file == nil { |
| return uintptr(syscall.InvalidHandle) |
| } |
| return uintptr(file.fd) |
| } |
| |
| // newFile returns a new File with the given file handle and name. |
| // Unlike NewFile, it does not check that h is syscall.InvalidHandle. |
| func newFile(h syscall.Handle, name string) *File { |
| f := &File{&file{fd: h, name: name}} |
| var m uint32 |
| if syscall.GetConsoleMode(f.fd, &m) == nil { |
| f.isConsole = true |
| } |
| runtime.SetFinalizer(f.file, (*file).close) |
| return f |
| } |
| |
| // NewFile returns a new File with the given file descriptor and name. |
| func NewFile(fd uintptr, name string) *File { |
| h := syscall.Handle(fd) |
| if h == syscall.InvalidHandle { |
| return nil |
| } |
| return newFile(h, name) |
| } |
| |
| // Auxiliary information if the File describes a directory |
| type dirInfo struct { |
| data syscall.Win32finddata |
| needdata bool |
| path string |
| isempty bool // set if FindFirstFile returns ERROR_FILE_NOT_FOUND |
| } |
| |
| func epipecheck(file *File, e error) { |
| } |
| |
| const DevNull = "NUL" |
| |
| func (f *file) isdir() bool { return f != nil && f.dirinfo != nil } |
| |
| func openFile(name string, flag int, perm FileMode) (file *File, err error) { |
| r, e := syscall.Open(name, flag|syscall.O_CLOEXEC, syscallMode(perm)) |
| if e != nil { |
| return nil, e |
| } |
| return NewFile(uintptr(r), name), nil |
| } |
| |
| func openDir(name string) (file *File, err error) { |
| maskp, e := syscall.UTF16PtrFromString(name + `\*`) |
| if e != nil { |
| return nil, e |
| } |
| d := new(dirInfo) |
| r, e := syscall.FindFirstFile(maskp, &d.data) |
| if e != nil { |
| // FindFirstFile returns ERROR_FILE_NOT_FOUND when |
| // no matching files can be found. Then, if directory |
| // exists, we should proceed. |
| if e != syscall.ERROR_FILE_NOT_FOUND { |
| return nil, e |
| } |
| var fa syscall.Win32FileAttributeData |
| namep, e := syscall.UTF16PtrFromString(name) |
| if e != nil { |
| return nil, e |
| } |
| e = syscall.GetFileAttributesEx(namep, syscall.GetFileExInfoStandard, (*byte)(unsafe.Pointer(&fa))) |
| if e != nil { |
| return nil, e |
| } |
| if fa.FileAttributes&syscall.FILE_ATTRIBUTE_DIRECTORY == 0 { |
| return nil, e |
| } |
| d.isempty = true |
| } |
| d.path = name |
| if !isAbs(d.path) { |
| cwd, _ := Getwd() |
| d.path = cwd + `\` + d.path |
| } |
| f := newFile(r, name) |
| f.dirinfo = d |
| return f, nil |
| } |
| |
| // OpenFile is the generalized open call; most users will use Open |
| // or Create instead. It opens the named file with specified flag |
| // (O_RDONLY etc.) and perm, (0666 etc.) if applicable. If successful, |
| // methods on the returned File can be used for I/O. |
| // If there is an error, it will be of type *PathError. |
| func OpenFile(name string, flag int, perm FileMode) (file *File, err error) { |
| if name == "" { |
| return nil, &PathError{"open", name, syscall.ENOENT} |
| } |
| r, errf := openFile(name, flag, perm) |
| if errf == nil { |
| return r, nil |
| } |
| r, errd := openDir(name) |
| if errd == nil { |
| if flag&O_WRONLY != 0 || flag&O_RDWR != 0 { |
| r.Close() |
| return nil, &PathError{"open", name, syscall.EISDIR} |
| } |
| return r, nil |
| } |
| return nil, &PathError{"open", name, errf} |
| } |
| |
| // Close closes the File, rendering it unusable for I/O. |
| // It returns an error, if any. |
| func (file *File) Close() error { |
| if file == nil { |
| return ErrInvalid |
| } |
| return file.file.close() |
| } |
| |
| func (file *file) close() error { |
| if file == nil { |
| return syscall.EINVAL |
| } |
| if file.isdir() && file.dirinfo.isempty { |
| // "special" empty directories |
| return nil |
| } |
| if file.fd == syscall.InvalidHandle { |
| return syscall.EINVAL |
| } |
| var e error |
| if file.isdir() { |
| e = syscall.FindClose(syscall.Handle(file.fd)) |
| } else { |
| e = syscall.CloseHandle(syscall.Handle(file.fd)) |
| } |
| var err error |
| if e != nil { |
| err = &PathError{"close", file.name, e} |
| } |
| file.fd = syscall.InvalidHandle // so it can't be closed again |
| |
| // no need for a finalizer anymore |
| runtime.SetFinalizer(file, nil) |
| return err |
| } |
| |
| func (file *File) readdir(n int) (fi []FileInfo, err error) { |
| if file == nil { |
| return nil, syscall.EINVAL |
| } |
| if !file.isdir() { |
| return nil, &PathError{"Readdir", file.name, syscall.ENOTDIR} |
| } |
| if !file.dirinfo.isempty && file.fd == syscall.InvalidHandle { |
| return nil, syscall.EINVAL |
| } |
| wantAll := n <= 0 |
| size := n |
| if wantAll { |
| n = -1 |
| size = 100 |
| } |
| fi = make([]FileInfo, 0, size) // Empty with room to grow. |
| d := &file.dirinfo.data |
| for n != 0 && !file.dirinfo.isempty { |
| if file.dirinfo.needdata { |
| e := syscall.FindNextFile(syscall.Handle(file.fd), d) |
| if e != nil { |
| if e == syscall.ERROR_NO_MORE_FILES { |
| break |
| } else { |
| err = &PathError{"FindNextFile", file.name, e} |
| if !wantAll { |
| fi = nil |
| } |
| return |
| } |
| } |
| } |
| file.dirinfo.needdata = true |
| name := string(syscall.UTF16ToString(d.FileName[0:])) |
| if name == "." || name == ".." { // Useless names |
| continue |
| } |
| f := &fileStat{ |
| name: name, |
| sys: syscall.Win32FileAttributeData{ |
| FileAttributes: d.FileAttributes, |
| CreationTime: d.CreationTime, |
| LastAccessTime: d.LastAccessTime, |
| LastWriteTime: d.LastWriteTime, |
| FileSizeHigh: d.FileSizeHigh, |
| FileSizeLow: d.FileSizeLow, |
| }, |
| path: file.dirinfo.path + `\` + name, |
| } |
| n-- |
| fi = append(fi, f) |
| } |
| if !wantAll && len(fi) == 0 { |
| return fi, io.EOF |
| } |
| return fi, nil |
| } |
| |
| // readConsole reads utf16 characters from console File, |
| // encodes them into utf8 and stores them in buffer b. |
| // It returns the number of utf8 bytes read and an error, if any. |
| func (f *File) readConsole(b []byte) (n int, err error) { |
| if len(b) == 0 { |
| return 0, nil |
| } |
| if len(f.readbuf) == 0 { |
| // syscall.ReadConsole seems to fail, if given large buffer. |
| // So limit the buffer to 16000 characters. |
| numBytes := len(b) |
| if numBytes > 16000 { |
| numBytes = 16000 |
| } |
| // get more input data from os |
| wchars := make([]uint16, numBytes) |
| var p *uint16 |
| if len(b) > 0 { |
| p = &wchars[0] |
| } |
| var nw uint32 |
| err := syscall.ReadConsole(f.fd, p, uint32(len(wchars)), &nw, nil) |
| if err != nil { |
| return 0, err |
| } |
| f.readbuf = utf16.Decode(wchars[:nw]) |
| } |
| for i, r := range f.readbuf { |
| if utf8.RuneLen(r) > len(b) { |
| f.readbuf = f.readbuf[i:] |
| return n, nil |
| } |
| nr := utf8.EncodeRune(b, r) |
| b = b[nr:] |
| n += nr |
| } |
| f.readbuf = nil |
| return n, nil |
| } |
| |
| // 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) { |
| f.l.Lock() |
| defer f.l.Unlock() |
| if f.isConsole { |
| return f.readConsole(b) |
| } |
| return syscall.Read(f.fd, b) |
| } |
| |
| // 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 0. |
| func (f *File) pread(b []byte, off int64) (n int, err error) { |
| f.l.Lock() |
| defer f.l.Unlock() |
| curoffset, e := syscall.Seek(f.fd, 0, 1) |
| if e != nil { |
| return 0, e |
| } |
| defer syscall.Seek(f.fd, curoffset, 0) |
| o := syscall.Overlapped{ |
| OffsetHigh: uint32(off >> 32), |
| Offset: uint32(off), |
| } |
| var done uint32 |
| e = syscall.ReadFile(syscall.Handle(f.fd), b, &done, &o) |
| if e != nil { |
| if e == syscall.ERROR_HANDLE_EOF { |
| // end of file |
| return 0, nil |
| } |
| return 0, e |
| } |
| return int(done), nil |
| } |
| |
| // writeConsole writes len(b) bytes to the console File. |
| // It returns the number of bytes written and an error, if any. |
| func (f *File) writeConsole(b []byte) (n int, err error) { |
| n = len(b) |
| runes := make([]rune, 0, 256) |
| if len(f.lastbits) > 0 { |
| b = append(f.lastbits, b...) |
| f.lastbits = nil |
| |
| } |
| for len(b) >= utf8.UTFMax || utf8.FullRune(b) { |
| r, l := utf8.DecodeRune(b) |
| runes = append(runes, r) |
| b = b[l:] |
| } |
| if len(b) > 0 { |
| f.lastbits = make([]byte, len(b)) |
| copy(f.lastbits, b) |
| } |
| // syscall.WriteConsole seems to fail, if given large buffer. |
| // So limit the buffer to 16000 characters. This number was |
| // discovered by experimenting with syscall.WriteConsole. |
| const maxWrite = 16000 |
| for len(runes) > 0 { |
| m := len(runes) |
| if m > maxWrite { |
| m = maxWrite |
| } |
| chunk := runes[:m] |
| runes = runes[m:] |
| uint16s := utf16.Encode(chunk) |
| for len(uint16s) > 0 { |
| var written uint32 |
| err = syscall.WriteConsole(f.fd, &uint16s[0], uint32(len(uint16s)), &written, nil) |
| if err != nil { |
| return 0, nil |
| } |
| uint16s = uint16s[written:] |
| } |
| } |
| return n, nil |
| } |
| |
| // 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) { |
| f.l.Lock() |
| defer f.l.Unlock() |
| if f.isConsole { |
| return f.writeConsole(b) |
| } |
| return syscall.Write(f.fd, b) |
| } |
| |
| // 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) { |
| f.l.Lock() |
| defer f.l.Unlock() |
| curoffset, e := syscall.Seek(f.fd, 0, 1) |
| if e != nil { |
| return 0, e |
| } |
| defer syscall.Seek(f.fd, curoffset, 0) |
| o := syscall.Overlapped{ |
| OffsetHigh: uint32(off >> 32), |
| Offset: uint32(off), |
| } |
| var done uint32 |
| e = syscall.WriteFile(syscall.Handle(f.fd), b, &done, &o) |
| if e != nil { |
| return 0, e |
| } |
| return int(done), nil |
| } |
| |
| // 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. |
| func (f *File) seek(offset int64, whence int) (ret int64, err error) { |
| f.l.Lock() |
| defer f.l.Unlock() |
| return syscall.Seek(f.fd, offset, whence) |
| } |
| |
| // Truncate changes the size of the named file. |
| // If the file is a symbolic link, it changes the size of the link's target. |
| func Truncate(name string, size int64) error { |
| f, e := OpenFile(name, O_WRONLY|O_CREATE, 0666) |
| if e != nil { |
| return e |
| } |
| defer f.Close() |
| e1 := f.Truncate(size) |
| if e1 != nil { |
| return e1 |
| } |
| return nil |
| } |
| |
| // Remove removes the named file or directory. |
| // If there is an error, it will be of type *PathError. |
| func Remove(name string) error { |
| p, e := syscall.UTF16PtrFromString(name) |
| if e != nil { |
| return &PathError{"remove", name, e} |
| } |
| |
| // Go file interface forces us to know whether |
| // name is a file or directory. Try both. |
| e = syscall.DeleteFile(p) |
| if e == nil { |
| return nil |
| } |
| e1 := syscall.RemoveDirectory(p) |
| if e1 == nil { |
| return nil |
| } |
| |
| // Both failed: figure out which error to return. |
| if e1 != e { |
| a, e2 := syscall.GetFileAttributes(p) |
| if e2 != nil { |
| e = e2 |
| } else { |
| if a&syscall.FILE_ATTRIBUTE_DIRECTORY != 0 { |
| e = e1 |
| } |
| } |
| } |
| return &PathError{"remove", name, e} |
| } |
| |
| // Pipe returns a connected pair of Files; reads from r return bytes written to w. |
| // It returns the files and an error, if any. |
| func Pipe() (r *File, w *File, err error) { |
| var p [2]syscall.Handle |
| |
| // See ../syscall/exec.go for description of lock. |
| syscall.ForkLock.RLock() |
| e := syscall.Pipe(p[0:]) |
| if e != nil { |
| syscall.ForkLock.RUnlock() |
| return nil, nil, NewSyscallError("pipe", e) |
| } |
| syscall.CloseOnExec(p[0]) |
| syscall.CloseOnExec(p[1]) |
| syscall.ForkLock.RUnlock() |
| |
| return NewFile(uintptr(p[0]), "|0"), NewFile(uintptr(p[1]), "|1"), nil |
| } |
| |
| // TempDir returns the default directory to use for temporary files. |
| func TempDir() string { |
| const pathSep = '\\' |
| dirw := make([]uint16, syscall.MAX_PATH) |
| n, _ := syscall.GetTempPath(uint32(len(dirw)), &dirw[0]) |
| if n > uint32(len(dirw)) { |
| dirw = make([]uint16, n) |
| n, _ = syscall.GetTempPath(uint32(len(dirw)), &dirw[0]) |
| if n > uint32(len(dirw)) { |
| n = 0 |
| } |
| } |
| if n > 0 && dirw[n-1] == pathSep { |
| n-- |
| } |
| return string(utf16.Decode(dirw[0:n])) |
| } |