Source file
src/os/file_unix.go
Documentation: os
1
2
3
4
5
6
7 package os
8
9 import (
10 "internal/poll"
11 "internal/syscall/unix"
12 "runtime"
13 "syscall"
14 )
15
16
17 func fixLongPath(path string) string {
18 return path
19 }
20
21 func rename(oldname, newname string) error {
22 fi, err := Lstat(newname)
23 if err == nil && fi.IsDir() {
24
25
26
27
28
29
30
31
32 if ofi, err := Lstat(oldname); err != nil {
33 if pe, ok := err.(*PathError); ok {
34 err = pe.Err
35 }
36 return &LinkError{"rename", oldname, newname, err}
37 } else if newname == oldname || !SameFile(fi, ofi) {
38 return &LinkError{"rename", oldname, newname, syscall.EEXIST}
39 }
40 }
41 err = ignoringEINTR(func() error {
42 return syscall.Rename(oldname, newname)
43 })
44 if err != nil {
45 return &LinkError{"rename", oldname, newname, err}
46 }
47 return nil
48 }
49
50
51
52
53
54 type file struct {
55 pfd poll.FD
56 name string
57 dirinfo *dirInfo
58 nonblock bool
59 stdoutOrErr bool
60 appendMode bool
61 }
62
63
64
65
66
67
68
69
70
71
72
73
74
75 func (f *File) Fd() uintptr {
76 if f == nil {
77 return ^(uintptr(0))
78 }
79
80
81
82
83
84
85 if f.nonblock {
86 f.pfd.SetBlocking()
87 }
88
89 return uintptr(f.pfd.Sysfd)
90 }
91
92
93
94
95
96
97
98
99
100
101 func NewFile(fd uintptr, name string) *File {
102 kind := kindNewFile
103 if nb, err := unix.IsNonblock(int(fd)); err == nil && nb {
104 kind = kindNonBlock
105 }
106 return newFile(fd, name, kind)
107 }
108
109
110 type newFileKind int
111
112 const (
113 kindNewFile newFileKind = iota
114 kindOpenFile
115 kindPipe
116 kindNonBlock
117 )
118
119
120
121
122 func newFile(fd uintptr, name string, kind newFileKind) *File {
123 fdi := int(fd)
124 if fdi < 0 {
125 return nil
126 }
127 f := &File{&file{
128 pfd: poll.FD{
129 Sysfd: fdi,
130 IsStream: true,
131 ZeroReadIsEOF: true,
132 },
133 name: name,
134 stdoutOrErr: fdi == 1 || fdi == 2,
135 }}
136
137 pollable := kind == kindOpenFile || kind == kindPipe || kind == kindNonBlock
138
139
140
141
142 if kind == kindOpenFile {
143 switch runtime.GOOS {
144 case "darwin", "ios", "dragonfly", "freebsd", "netbsd", "openbsd":
145 var st syscall.Stat_t
146 err := ignoringEINTR(func() error {
147 return syscall.Fstat(fdi, &st)
148 })
149 typ := st.Mode & syscall.S_IFMT
150
151
152
153
154
155
156
157 if err == nil && (typ == syscall.S_IFREG || typ == syscall.S_IFDIR) {
158 pollable = false
159 }
160
161
162
163
164
165 if (runtime.GOOS == "darwin" || runtime.GOOS == "ios") && typ == syscall.S_IFIFO {
166 pollable = false
167 }
168 }
169 }
170
171 if err := f.pfd.Init("file", pollable); err != nil {
172
173
174
175
176
177
178 } else if pollable {
179
180
181 if err := syscall.SetNonblock(fdi, true); err == nil {
182 f.nonblock = true
183 }
184 }
185
186 runtime.SetFinalizer(f.file, (*file).close)
187 return f
188 }
189
190
191
192
193 func epipecheck(file *File, e error) {
194 if e == syscall.EPIPE && file.stdoutOrErr {
195 sigpipe()
196 }
197 }
198
199
200
201 const DevNull = "/dev/null"
202
203
204
205 func openFileNolog(name string, flag int, perm FileMode) (*File, error) {
206 setSticky := false
207 if !supportsCreateWithStickyBit && flag&O_CREATE != 0 && perm&ModeSticky != 0 {
208 if _, err := Stat(name); IsNotExist(err) {
209 setSticky = true
210 }
211 }
212
213 var r int
214 for {
215 var e error
216 r, e = syscall.Open(name, flag|syscall.O_CLOEXEC, syscallMode(perm))
217 if e == nil {
218 break
219 }
220
221
222 if e == syscall.EINTR {
223 continue
224 }
225
226 return nil, &PathError{Op: "open", Path: name, Err: e}
227 }
228
229
230 if setSticky {
231 setStickyBit(name)
232 }
233
234
235
236 if !supportsCloseOnExec {
237 syscall.CloseOnExec(r)
238 }
239
240 return newFile(uintptr(r), name, kindOpenFile), nil
241 }
242
243 func (file *file) close() error {
244 if file == nil {
245 return syscall.EINVAL
246 }
247 if file.dirinfo != nil {
248 file.dirinfo.close()
249 }
250 var err error
251 if e := file.pfd.Close(); e != nil {
252 if e == poll.ErrFileClosing {
253 e = ErrClosed
254 }
255 err = &PathError{Op: "close", Path: file.name, Err: e}
256 }
257
258
259 runtime.SetFinalizer(file, nil)
260 return err
261 }
262
263
264
265
266
267 func (f *File) seek(offset int64, whence int) (ret int64, err error) {
268 if f.dirinfo != nil {
269
270
271 f.dirinfo.close()
272 f.dirinfo = nil
273 }
274 ret, err = f.pfd.Seek(offset, whence)
275 runtime.KeepAlive(f)
276 return ret, err
277 }
278
279
280
281
282 func Truncate(name string, size int64) error {
283 e := ignoringEINTR(func() error {
284 return syscall.Truncate(name, size)
285 })
286 if e != nil {
287 return &PathError{Op: "truncate", Path: name, Err: e}
288 }
289 return nil
290 }
291
292
293
294 func Remove(name string) error {
295
296
297
298
299 e := ignoringEINTR(func() error {
300 return syscall.Unlink(name)
301 })
302 if e == nil {
303 return nil
304 }
305 e1 := ignoringEINTR(func() error {
306 return syscall.Rmdir(name)
307 })
308 if e1 == nil {
309 return nil
310 }
311
312
313
314
315
316
317
318
319
320
321 if e1 != syscall.ENOTDIR {
322 e = e1
323 }
324 return &PathError{Op: "remove", Path: name, Err: e}
325 }
326
327 func tempDir() string {
328 dir := Getenv("TMPDIR")
329 if dir == "" {
330 if runtime.GOOS == "android" {
331 dir = "/data/local/tmp"
332 } else {
333 dir = "/tmp"
334 }
335 }
336 return dir
337 }
338
339
340
341 func Link(oldname, newname string) error {
342 e := ignoringEINTR(func() error {
343 return syscall.Link(oldname, newname)
344 })
345 if e != nil {
346 return &LinkError{"link", oldname, newname, e}
347 }
348 return nil
349 }
350
351
352
353 func Symlink(oldname, newname string) error {
354 e := ignoringEINTR(func() error {
355 return syscall.Symlink(oldname, newname)
356 })
357 if e != nil {
358 return &LinkError{"symlink", oldname, newname, e}
359 }
360 return nil
361 }
362
363
364
365 func Readlink(name string) (string, error) {
366 for len := 128; ; len *= 2 {
367 b := make([]byte, len)
368 var (
369 n int
370 e error
371 )
372 for {
373 n, e = fixCount(syscall.Readlink(name, b))
374 if e != syscall.EINTR {
375 break
376 }
377 }
378
379 if runtime.GOOS == "aix" && e == syscall.ERANGE {
380 continue
381 }
382 if e != nil {
383 return "", &PathError{Op: "readlink", Path: name, Err: e}
384 }
385 if n < len {
386 return string(b[0:n]), nil
387 }
388 }
389 }
390
391 type unixDirent struct {
392 parent string
393 name string
394 typ FileMode
395 info FileInfo
396 }
397
398 func (d *unixDirent) Name() string { return d.name }
399 func (d *unixDirent) IsDir() bool { return d.typ.IsDir() }
400 func (d *unixDirent) Type() FileMode { return d.typ }
401
402 func (d *unixDirent) Info() (FileInfo, error) {
403 if d.info != nil {
404 return d.info, nil
405 }
406 return lstat(d.parent + "/" + d.name)
407 }
408
409 func newUnixDirent(parent, name string, typ FileMode) (DirEntry, error) {
410 ude := &unixDirent{
411 parent: parent,
412 name: name,
413 typ: typ,
414 }
415 if typ != ^FileMode(0) && !testingForceReadDirLstat {
416 return ude, nil
417 }
418
419 info, err := lstat(parent + "/" + name)
420 if err != nil {
421 return nil, err
422 }
423
424 ude.typ = info.Mode().Type()
425 ude.info = info
426 return ude, nil
427 }
428
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