| 1 |
747 |
jeremybenn |
// Copyright 2011 The Go Authors. All rights reserved.
|
| 2 |
|
|
// Use of this source code is governed by a BSD-style
|
| 3 |
|
|
// license that can be found in the LICENSE file.
|
| 4 |
|
|
|
| 5 |
|
|
package os
|
| 6 |
|
|
|
| 7 |
|
|
import (
|
| 8 |
|
|
"runtime"
|
| 9 |
|
|
"syscall"
|
| 10 |
|
|
"time"
|
| 11 |
|
|
)
|
| 12 |
|
|
|
| 13 |
|
|
// File represents an open file descriptor.
|
| 14 |
|
|
type File struct {
|
| 15 |
|
|
*file
|
| 16 |
|
|
}
|
| 17 |
|
|
|
| 18 |
|
|
// file is the real representation of *File.
|
| 19 |
|
|
// The extra level of indirection ensures that no clients of os
|
| 20 |
|
|
// can overwrite this data, which could cause the finalizer
|
| 21 |
|
|
// to close the wrong file descriptor.
|
| 22 |
|
|
type file struct {
|
| 23 |
|
|
fd int
|
| 24 |
|
|
name string
|
| 25 |
|
|
dirinfo *dirInfo // nil unless directory being read
|
| 26 |
|
|
}
|
| 27 |
|
|
|
| 28 |
|
|
// Fd returns the integer Unix file descriptor referencing the open file.
|
| 29 |
|
|
func (file *File) Fd() int {
|
| 30 |
|
|
if file == nil {
|
| 31 |
|
|
return -1
|
| 32 |
|
|
}
|
| 33 |
|
|
return file.fd
|
| 34 |
|
|
}
|
| 35 |
|
|
|
| 36 |
|
|
// NewFile returns a new File with the given file descriptor and name.
|
| 37 |
|
|
func NewFile(fd int, name string) *File {
|
| 38 |
|
|
if fd < 0 {
|
| 39 |
|
|
return nil
|
| 40 |
|
|
}
|
| 41 |
|
|
f := &File{&file{fd: fd, name: name}}
|
| 42 |
|
|
runtime.SetFinalizer(f.file, (*file).close)
|
| 43 |
|
|
return f
|
| 44 |
|
|
}
|
| 45 |
|
|
|
| 46 |
|
|
// Auxiliary information if the File describes a directory
|
| 47 |
|
|
type dirInfo struct {
|
| 48 |
|
|
buf [syscall.STATMAX]byte // buffer for directory I/O
|
| 49 |
|
|
nbuf int // length of buf; return value from Read
|
| 50 |
|
|
bufp int // location of next record in buf.
|
| 51 |
|
|
}
|
| 52 |
|
|
|
| 53 |
|
|
func epipecheck(file *File, e error) {
|
| 54 |
|
|
}
|
| 55 |
|
|
|
| 56 |
|
|
// DevNull is the name of the operating system's ``null device.''
|
| 57 |
|
|
// On Unix-like systems, it is "/dev/null"; on Windows, "NUL".
|
| 58 |
|
|
const DevNull = "/dev/null"
|
| 59 |
|
|
|
| 60 |
|
|
// syscallMode returns the syscall-specific mode bits from Go's portable mode bits.
|
| 61 |
|
|
func syscallMode(i FileMode) (o uint32) {
|
| 62 |
|
|
o |= uint32(i.Perm())
|
| 63 |
|
|
if i&ModeAppend != 0 {
|
| 64 |
|
|
o |= syscall.DMAPPEND
|
| 65 |
|
|
}
|
| 66 |
|
|
if i&ModeExclusive != 0 {
|
| 67 |
|
|
o |= syscall.DMEXCL
|
| 68 |
|
|
}
|
| 69 |
|
|
if i&ModeTemporary != 0 {
|
| 70 |
|
|
o |= syscall.DMTMP
|
| 71 |
|
|
}
|
| 72 |
|
|
return
|
| 73 |
|
|
}
|
| 74 |
|
|
|
| 75 |
|
|
// OpenFile is the generalized open call; most users will use Open
|
| 76 |
|
|
// or Create instead. It opens the named file with specified flag
|
| 77 |
|
|
// (O_RDONLY etc.) and perm, (0666 etc.) if applicable. If successful,
|
| 78 |
|
|
// methods on the returned File can be used for I/O.
|
| 79 |
|
|
// It returns the File and an error, if any.
|
| 80 |
|
|
func OpenFile(name string, flag int, perm FileMode) (file *File, err error) {
|
| 81 |
|
|
var (
|
| 82 |
|
|
fd int
|
| 83 |
|
|
e error
|
| 84 |
|
|
create bool
|
| 85 |
|
|
excl bool
|
| 86 |
|
|
trunc bool
|
| 87 |
|
|
append bool
|
| 88 |
|
|
)
|
| 89 |
|
|
|
| 90 |
|
|
if flag&O_CREATE == O_CREATE {
|
| 91 |
|
|
flag = flag & ^O_CREATE
|
| 92 |
|
|
create = true
|
| 93 |
|
|
}
|
| 94 |
|
|
if flag&O_EXCL == O_EXCL {
|
| 95 |
|
|
excl = true
|
| 96 |
|
|
}
|
| 97 |
|
|
if flag&O_TRUNC == O_TRUNC {
|
| 98 |
|
|
trunc = true
|
| 99 |
|
|
}
|
| 100 |
|
|
// O_APPEND is emulated on Plan 9
|
| 101 |
|
|
if flag&O_APPEND == O_APPEND {
|
| 102 |
|
|
flag = flag &^ O_APPEND
|
| 103 |
|
|
append = true
|
| 104 |
|
|
}
|
| 105 |
|
|
|
| 106 |
|
|
syscall.ForkLock.RLock()
|
| 107 |
|
|
if (create && trunc) || excl {
|
| 108 |
|
|
fd, e = syscall.Create(name, flag, syscallMode(perm))
|
| 109 |
|
|
} else {
|
| 110 |
|
|
fd, e = syscall.Open(name, flag)
|
| 111 |
|
|
if e != nil && create {
|
| 112 |
|
|
var e1 error
|
| 113 |
|
|
fd, e1 = syscall.Create(name, flag, syscallMode(perm))
|
| 114 |
|
|
if e1 == nil {
|
| 115 |
|
|
e = nil
|
| 116 |
|
|
}
|
| 117 |
|
|
}
|
| 118 |
|
|
}
|
| 119 |
|
|
syscall.ForkLock.RUnlock()
|
| 120 |
|
|
|
| 121 |
|
|
if e != nil {
|
| 122 |
|
|
return nil, &PathError{"open", name, e}
|
| 123 |
|
|
}
|
| 124 |
|
|
|
| 125 |
|
|
if append {
|
| 126 |
|
|
if _, e = syscall.Seek(fd, 0, SEEK_END); e != nil {
|
| 127 |
|
|
return nil, &PathError{"seek", name, e}
|
| 128 |
|
|
}
|
| 129 |
|
|
}
|
| 130 |
|
|
|
| 131 |
|
|
return NewFile(fd, name), nil
|
| 132 |
|
|
}
|
| 133 |
|
|
|
| 134 |
|
|
// Close closes the File, rendering it unusable for I/O.
|
| 135 |
|
|
// It returns an error, if any.
|
| 136 |
|
|
func (file *File) Close() error {
|
| 137 |
|
|
return file.file.close()
|
| 138 |
|
|
}
|
| 139 |
|
|
|
| 140 |
|
|
func (file *file) close() error {
|
| 141 |
|
|
if file == nil || file.fd < 0 {
|
| 142 |
|
|
return Ebadfd
|
| 143 |
|
|
}
|
| 144 |
|
|
var err error
|
| 145 |
|
|
syscall.ForkLock.RLock()
|
| 146 |
|
|
if e := syscall.Close(file.fd); e != nil {
|
| 147 |
|
|
err = &PathError{"close", file.name, e}
|
| 148 |
|
|
}
|
| 149 |
|
|
syscall.ForkLock.RUnlock()
|
| 150 |
|
|
file.fd = -1 // so it can't be closed again
|
| 151 |
|
|
|
| 152 |
|
|
// no need for a finalizer anymore
|
| 153 |
|
|
runtime.SetFinalizer(file, nil)
|
| 154 |
|
|
return err
|
| 155 |
|
|
}
|
| 156 |
|
|
|
| 157 |
|
|
// Stat returns the FileInfo structure describing file.
|
| 158 |
|
|
// It returns the FileInfo and an error, if any.
|
| 159 |
|
|
func (f *File) Stat() (FileInfo, error) {
|
| 160 |
|
|
d, err := dirstat(f)
|
| 161 |
|
|
if err != nil {
|
| 162 |
|
|
return nil, err
|
| 163 |
|
|
}
|
| 164 |
|
|
return fileInfoFromStat(d), nil
|
| 165 |
|
|
}
|
| 166 |
|
|
|
| 167 |
|
|
// Truncate changes the size of the file.
|
| 168 |
|
|
// It does not change the I/O offset.
|
| 169 |
|
|
func (f *File) Truncate(size int64) error {
|
| 170 |
|
|
var d Dir
|
| 171 |
|
|
d.Null()
|
| 172 |
|
|
|
| 173 |
|
|
d.Length = uint64(size)
|
| 174 |
|
|
|
| 175 |
|
|
if e := syscall.Fwstat(f.fd, pdir(nil, &d)); e != nil {
|
| 176 |
|
|
return &PathError{"truncate", f.name, e}
|
| 177 |
|
|
}
|
| 178 |
|
|
return nil
|
| 179 |
|
|
}
|
| 180 |
|
|
|
| 181 |
|
|
const chmodMask = uint32(syscall.DMAPPEND | syscall.DMEXCL | syscall.DMTMP | ModePerm)
|
| 182 |
|
|
|
| 183 |
|
|
// Chmod changes the mode of the file to mode.
|
| 184 |
|
|
func (f *File) Chmod(mode FileMode) error {
|
| 185 |
|
|
var d Dir
|
| 186 |
|
|
|
| 187 |
|
|
odir, e := dirstat(f)
|
| 188 |
|
|
if e != nil {
|
| 189 |
|
|
return &PathError{"chmod", f.name, e}
|
| 190 |
|
|
}
|
| 191 |
|
|
d.Null()
|
| 192 |
|
|
d.Mode = odir.Mode&^chmodMask | syscallMode(mode)&chmodMask
|
| 193 |
|
|
if e := syscall.Fwstat(f.fd, pdir(nil, &d)); e != nil {
|
| 194 |
|
|
return &PathError{"chmod", f.name, e}
|
| 195 |
|
|
}
|
| 196 |
|
|
return nil
|
| 197 |
|
|
}
|
| 198 |
|
|
|
| 199 |
|
|
// Sync commits the current contents of the file to stable storage.
|
| 200 |
|
|
// Typically, this means flushing the file system's in-memory copy
|
| 201 |
|
|
// of recently written data to disk.
|
| 202 |
|
|
func (f *File) Sync() (err error) {
|
| 203 |
|
|
if f == nil {
|
| 204 |
|
|
return EINVAL
|
| 205 |
|
|
}
|
| 206 |
|
|
|
| 207 |
|
|
var d Dir
|
| 208 |
|
|
d.Null()
|
| 209 |
|
|
|
| 210 |
|
|
if e := syscall.Fwstat(f.fd, pdir(nil, &d)); e != nil {
|
| 211 |
|
|
return NewSyscallError("fsync", e)
|
| 212 |
|
|
}
|
| 213 |
|
|
return nil
|
| 214 |
|
|
}
|
| 215 |
|
|
|
| 216 |
|
|
// read reads up to len(b) bytes from the File.
|
| 217 |
|
|
// It returns the number of bytes read and an error, if any.
|
| 218 |
|
|
func (f *File) read(b []byte) (n int, err error) {
|
| 219 |
|
|
return syscall.Read(f.fd, b)
|
| 220 |
|
|
}
|
| 221 |
|
|
|
| 222 |
|
|
// pread reads len(b) bytes from the File starting at byte offset off.
|
| 223 |
|
|
// It returns the number of bytes read and the error, if any.
|
| 224 |
|
|
// EOF is signaled by a zero count with err set to nil.
|
| 225 |
|
|
func (f *File) pread(b []byte, off int64) (n int, err error) {
|
| 226 |
|
|
return syscall.Pread(f.fd, b, off)
|
| 227 |
|
|
}
|
| 228 |
|
|
|
| 229 |
|
|
// write writes len(b) bytes to the File.
|
| 230 |
|
|
// It returns the number of bytes written and an error, if any.
|
| 231 |
|
|
func (f *File) write(b []byte) (n int, err error) {
|
| 232 |
|
|
return syscall.Write(f.fd, b)
|
| 233 |
|
|
}
|
| 234 |
|
|
|
| 235 |
|
|
// pwrite writes len(b) bytes to the File starting at byte offset off.
|
| 236 |
|
|
// It returns the number of bytes written and an error, if any.
|
| 237 |
|
|
func (f *File) pwrite(b []byte, off int64) (n int, err error) {
|
| 238 |
|
|
return syscall.Pwrite(f.fd, b, off)
|
| 239 |
|
|
}
|
| 240 |
|
|
|
| 241 |
|
|
// seek sets the offset for the next Read or Write on file to offset, interpreted
|
| 242 |
|
|
// according to whence: 0 means relative to the origin of the file, 1 means
|
| 243 |
|
|
// relative to the current offset, and 2 means relative to the end.
|
| 244 |
|
|
// It returns the new offset and an error, if any.
|
| 245 |
|
|
func (f *File) seek(offset int64, whence int) (ret int64, err error) {
|
| 246 |
|
|
return syscall.Seek(f.fd, offset, whence)
|
| 247 |
|
|
}
|
| 248 |
|
|
|
| 249 |
|
|
// Truncate changes the size of the named file.
|
| 250 |
|
|
// If the file is a symbolic link, it changes the size of the link's target.
|
| 251 |
|
|
func Truncate(name string, size int64) error {
|
| 252 |
|
|
var d Dir
|
| 253 |
|
|
d.Null()
|
| 254 |
|
|
|
| 255 |
|
|
d.Length = uint64(size)
|
| 256 |
|
|
|
| 257 |
|
|
if e := syscall.Wstat(name, pdir(nil, &d)); e != nil {
|
| 258 |
|
|
return &PathError{"truncate", name, e}
|
| 259 |
|
|
}
|
| 260 |
|
|
return nil
|
| 261 |
|
|
}
|
| 262 |
|
|
|
| 263 |
|
|
// Remove removes the named file or directory.
|
| 264 |
|
|
func Remove(name string) error {
|
| 265 |
|
|
if e := syscall.Remove(name); e != nil {
|
| 266 |
|
|
return &PathError{"remove", name, e}
|
| 267 |
|
|
}
|
| 268 |
|
|
return nil
|
| 269 |
|
|
}
|
| 270 |
|
|
|
| 271 |
|
|
// Rename renames a file.
|
| 272 |
|
|
func Rename(oldname, newname string) error {
|
| 273 |
|
|
var d Dir
|
| 274 |
|
|
d.Null()
|
| 275 |
|
|
|
| 276 |
|
|
d.Name = newname
|
| 277 |
|
|
|
| 278 |
|
|
if e := syscall.Wstat(oldname, pdir(nil, &d)); e != nil {
|
| 279 |
|
|
return &PathError{"rename", oldname, e}
|
| 280 |
|
|
}
|
| 281 |
|
|
return nil
|
| 282 |
|
|
}
|
| 283 |
|
|
|
| 284 |
|
|
// Chmod changes the mode of the named file to mode.
|
| 285 |
|
|
func Chmod(name string, mode FileMode) error {
|
| 286 |
|
|
var d Dir
|
| 287 |
|
|
|
| 288 |
|
|
odir, e := dirstat(name)
|
| 289 |
|
|
if e != nil {
|
| 290 |
|
|
return &PathError{"chmod", name, e}
|
| 291 |
|
|
}
|
| 292 |
|
|
d.Null()
|
| 293 |
|
|
d.Mode = odir.Mode&^chmodMask | syscallMode(mode)&chmodMask
|
| 294 |
|
|
if e := syscall.Wstat(name, pdir(nil, &d)); e != nil {
|
| 295 |
|
|
return &PathError{"chmod", name, e}
|
| 296 |
|
|
}
|
| 297 |
|
|
return nil
|
| 298 |
|
|
}
|
| 299 |
|
|
|
| 300 |
|
|
// Chtimes changes the access and modification times of the named
|
| 301 |
|
|
// file, similar to the Unix utime() or utimes() functions.
|
| 302 |
|
|
//
|
| 303 |
|
|
// The underlying filesystem may truncate or round the values to a
|
| 304 |
|
|
// less precise time unit.
|
| 305 |
|
|
func Chtimes(name string, atime time.Time, mtime time.Time) error {
|
| 306 |
|
|
var d Dir
|
| 307 |
|
|
d.Null()
|
| 308 |
|
|
|
| 309 |
|
|
d.Atime = uint32(atime.Unix())
|
| 310 |
|
|
d.Mtime = uint32(mtime.Unix())
|
| 311 |
|
|
|
| 312 |
|
|
if e := syscall.Wstat(name, pdir(nil, &d)); e != nil {
|
| 313 |
|
|
return &PathError{"chtimes", name, e}
|
| 314 |
|
|
}
|
| 315 |
|
|
return nil
|
| 316 |
|
|
}
|
| 317 |
|
|
|
| 318 |
|
|
func Pipe() (r *File, w *File, err error) {
|
| 319 |
|
|
var p [2]int
|
| 320 |
|
|
|
| 321 |
|
|
syscall.ForkLock.RLock()
|
| 322 |
|
|
if e := syscall.Pipe(p[0:]); e != nil {
|
| 323 |
|
|
syscall.ForkLock.RUnlock()
|
| 324 |
|
|
return nil, nil, NewSyscallError("pipe", e)
|
| 325 |
|
|
}
|
| 326 |
|
|
syscall.ForkLock.RUnlock()
|
| 327 |
|
|
|
| 328 |
|
|
return NewFile(p[0], "|0"), NewFile(p[1], "|1"), nil
|
| 329 |
|
|
}
|
| 330 |
|
|
|
| 331 |
|
|
// not supported on Plan 9
|
| 332 |
|
|
|
| 333 |
|
|
// Link creates a hard link.
|
| 334 |
|
|
func Link(oldname, newname string) error {
|
| 335 |
|
|
return EPLAN9
|
| 336 |
|
|
}
|
| 337 |
|
|
|
| 338 |
|
|
func Symlink(oldname, newname string) error {
|
| 339 |
|
|
return EPLAN9
|
| 340 |
|
|
}
|
| 341 |
|
|
|
| 342 |
|
|
func Readlink(name string) (string, error) {
|
| 343 |
|
|
return "", EPLAN9
|
| 344 |
|
|
}
|
| 345 |
|
|
|
| 346 |
|
|
func Chown(name string, uid, gid int) error {
|
| 347 |
|
|
return EPLAN9
|
| 348 |
|
|
}
|
| 349 |
|
|
|
| 350 |
|
|
func Lchown(name string, uid, gid int) error {
|
| 351 |
|
|
return EPLAN9
|
| 352 |
|
|
}
|
| 353 |
|
|
|
| 354 |
|
|
func (f *File) Chown(uid, gid int) error {
|
| 355 |
|
|
return EPLAN9
|
| 356 |
|
|
}
|
| 357 |
|
|
|
| 358 |
|
|
// TempDir returns the default directory to use for temporary files.
|
| 359 |
|
|
func TempDir() string {
|
| 360 |
|
|
return "/tmp"
|
| 361 |
|
|
}
|
