glibc (2.38)
1 /* Copyright (C) 1991-2023 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18 /*
19 * POSIX Standard: 6.5 File Control Operations <fcntl.h>
20 */
21
22 #ifndef _FCNTL_H
23 #define _FCNTL_H 1
24
25 #include <features.h>
26
27 /* This must be early so <bits/fcntl.h> can define types winningly. */
28 __BEGIN_DECLS
29
30 /* Get __mode_t, __dev_t and __off_t .*/
31 #include <bits/types.h>
32
33 /* Get the definitions of O_*, F_*, FD_*: all the
34 numbers and flag bits for `open', `fcntl', et al. */
35 #include <bits/fcntl.h>
36
37 /* Detect if open needs mode as a third argument (or for openat as a fourth
38 argument). */
39 #ifdef __O_TMPFILE
40 # define __OPEN_NEEDS_MODE(oflag) \
41 (((oflag) & O_CREAT) != 0 || ((oflag) & __O_TMPFILE) == __O_TMPFILE)
42 #else
43 # define __OPEN_NEEDS_MODE(oflag) (((oflag) & O_CREAT) != 0)
44 #endif
45
46 /* POSIX.1-2001 specifies that these types are defined by <fcntl.h>.
47 Earlier POSIX standards permitted any type ending in `_t' to be defined
48 by any POSIX header, so we don't conditionalize the definitions here. */
49 #ifndef __mode_t_defined
50 typedef __mode_t mode_t;
51 # define __mode_t_defined
52 #endif
53
54 #ifndef __off_t_defined
55 # ifndef __USE_FILE_OFFSET64
56 typedef __off_t off_t;
57 # else
58 typedef __off64_t off_t;
59 # endif
60 # define __off_t_defined
61 #endif
62
63 #if defined __USE_LARGEFILE64 && !defined __off64_t_defined
64 typedef __off64_t off64_t;
65 # define __off64_t_defined
66 #endif
67
68 #ifndef __pid_t_defined
69 typedef __pid_t pid_t;
70 # define __pid_t_defined
71 #endif
72
73 /* For XPG all symbols from <sys/stat.h> should also be available. */
74 #ifdef __USE_XOPEN2K8
75 # include <bits/types/struct_timespec.h>
76 #endif
77 #if defined __USE_XOPEN || defined __USE_XOPEN2K8
78 # include <bits/stat.h>
79
80 # define S_IFMT __S_IFMT
81 # define S_IFDIR __S_IFDIR
82 # define S_IFCHR __S_IFCHR
83 # define S_IFBLK __S_IFBLK
84 # define S_IFREG __S_IFREG
85 # ifdef __S_IFIFO
86 # define S_IFIFO __S_IFIFO
87 # endif
88 # ifdef __S_IFLNK
89 # define S_IFLNK __S_IFLNK
90 # endif
91 # if (defined __USE_UNIX98 || defined __USE_XOPEN2K8) && defined __S_IFSOCK
92 # define S_IFSOCK __S_IFSOCK
93 # endif
94
95 /* Protection bits. */
96
97 # define S_ISUID __S_ISUID /* Set user ID on execution. */
98 # define S_ISGID __S_ISGID /* Set group ID on execution. */
99
100 # if defined __USE_MISC || defined __USE_XOPEN
101 /* Save swapped text after use (sticky bit). This is pretty well obsolete. */
102 # define S_ISVTX __S_ISVTX
103 # endif
104
105 # define S_IRUSR __S_IREAD /* Read by owner. */
106 # define S_IWUSR __S_IWRITE /* Write by owner. */
107 # define S_IXUSR __S_IEXEC /* Execute by owner. */
108 /* Read, write, and execute by owner. */
109 # define S_IRWXU (__S_IREAD|__S_IWRITE|__S_IEXEC)
110
111 # define S_IRGRP (S_IRUSR >> 3) /* Read by group. */
112 # define S_IWGRP (S_IWUSR >> 3) /* Write by group. */
113 # define S_IXGRP (S_IXUSR >> 3) /* Execute by group. */
114 /* Read, write, and execute by group. */
115 # define S_IRWXG (S_IRWXU >> 3)
116
117 # define S_IROTH (S_IRGRP >> 3) /* Read by others. */
118 # define S_IWOTH (S_IWGRP >> 3) /* Write by others. */
119 # define S_IXOTH (S_IXGRP >> 3) /* Execute by others. */
120 /* Read, write, and execute by others. */
121 # define S_IRWXO (S_IRWXG >> 3)
122 #endif
123
124 #ifdef __USE_MISC
125 # ifndef R_OK /* Verbatim from <unistd.h>. Ugh. */
126 /* Values for the second argument to access.
127 These may be OR'd together. */
128 # define R_OK 4 /* Test for read permission. */
129 # define W_OK 2 /* Test for write permission. */
130 # define X_OK 1 /* Test for execute permission. */
131 # define F_OK 0 /* Test for existence. */
132 # endif
133 #endif /* Use misc. */
134
135 /* XPG wants the following symbols. <stdio.h> has the same definitions. */
136 #if defined __USE_XOPEN || defined __USE_XOPEN2K8
137 # define SEEK_SET 0 /* Seek from beginning of file. */
138 # define SEEK_CUR 1 /* Seek from current position. */
139 # define SEEK_END 2 /* Seek from end of file. */
140 #endif /* XPG */
141
142 /* The constants AT_REMOVEDIR and AT_EACCESS have the same value. AT_EACCESS
143 is meaningful only to faccessat, while AT_REMOVEDIR is meaningful only to
144 unlinkat. The two functions do completely different things and therefore,
145 the flags can be allowed to overlap. For example, passing AT_REMOVEDIR to
146 faccessat would be undefined behavior and thus treating it equivalent to
147 AT_EACCESS is valid undefined behavior. */
148 #ifdef __USE_ATFILE
149 # define AT_FDCWD -100 /* Special value used to indicate
150 the *at functions should use the
151 current working directory. */
152 # define AT_SYMLINK_NOFOLLOW 0x100 /* Do not follow symbolic links. */
153 # define AT_REMOVEDIR 0x200 /* Remove directory instead of
154 unlinking file. */
155 # define AT_SYMLINK_FOLLOW 0x400 /* Follow symbolic links. */
156 # ifdef __USE_GNU
157 # define AT_NO_AUTOMOUNT 0x800 /* Suppress terminal automount
158 traversal. */
159 # define AT_EMPTY_PATH 0x1000 /* Allow empty relative pathname. */
160 # define AT_STATX_SYNC_TYPE 0x6000
161 # define AT_STATX_SYNC_AS_STAT 0x0000
162 # define AT_STATX_FORCE_SYNC 0x2000
163 # define AT_STATX_DONT_SYNC 0x4000
164 # define AT_RECURSIVE 0x8000 /* Apply to the entire subtree. */
165 # endif
166 # define AT_EACCESS 0x200 /* Test access permitted for
167 effective IDs, not real IDs. */
168 #endif
169
170 /* Do the file control operation described by CMD on FD.
171 The remaining arguments are interpreted depending on CMD.
172
173 This function is a cancellation point and therefore not marked with
174 __THROW. */
175 #ifndef __USE_TIME_BITS64
176 # ifndef __USE_FILE_OFFSET64
177 extern int fcntl (int __fd, int __cmd, ...);
178 # else
179 # ifdef __REDIRECT
180 extern int __REDIRECT (fcntl, (int __fd, int __cmd, ...), fcntl64);
181 # else
182 # define fcntl fcntl64
183 # endif
184 # endif
185 # ifdef __USE_LARGEFILE64
186 extern int fcntl64 (int __fd, int __cmd, ...);
187 # endif
188 #else /* __USE_TIME_BITS64 */
189 # ifdef __REDIRECT
190 extern int __REDIRECT_NTH (fcntl, (int __fd, int __request, ...),
191 __fcntl_time64);
192 extern int __REDIRECT_NTH (fcntl64, (int __fd, int __request, ...),
193 __fcntl_time64);
194 # else
195 extern int __fcntl_time64 (int __fd, int __request, ...) __THROW;
196 # define fcntl64 __fcntl_time64
197 # define fcntl __fcntl_time64
198 # endif
199 #endif
200
201 /* Open FILE and return a new file descriptor for it, or -1 on error.
202 OFLAG determines the type of access used. If O_CREAT or O_TMPFILE is set
203 in OFLAG, the third argument is taken as a `mode_t', the mode of the
204 created file.
205
206 This function is a cancellation point and therefore not marked with
207 __THROW. */
208 #ifndef __USE_FILE_OFFSET64
209 extern int open (const char *__file, int __oflag, ...) __nonnull ((1));
210 #else
211 # ifdef __REDIRECT
212 extern int __REDIRECT (open, (const char *__file, int __oflag, ...), open64)
213 __nonnull ((1));
214 # else
215 # define open open64
216 # endif
217 #endif
218 #ifdef __USE_LARGEFILE64
219 extern int open64 (const char *__file, int __oflag, ...) __nonnull ((1));
220 #endif
221
222 #ifdef __USE_ATFILE
223 /* Similar to `open' but a relative path name is interpreted relative to
224 the directory for which FD is a descriptor.
225
226 NOTE: some other `openat' implementation support additional functionality
227 through this interface, especially using the O_XATTR flag. This is not
228 yet supported here.
229
230 This function is a cancellation point and therefore not marked with
231 __THROW. */
232 # ifndef __USE_FILE_OFFSET64
233 extern int openat (int __fd, const char *__file, int __oflag, ...)
234 __nonnull ((2));
235 # else
236 # ifdef __REDIRECT
237 extern int __REDIRECT (openat, (int __fd, const char *__file, int __oflag,
238 ...), openat64) __nonnull ((2));
239 # else
240 # define openat openat64
241 # endif
242 # endif
243 # ifdef __USE_LARGEFILE64
244 extern int openat64 (int __fd, const char *__file, int __oflag, ...)
245 __nonnull ((2));
246 # endif
247 #endif
248
249 /* Create and open FILE, with mode MODE. This takes an `int' MODE
250 argument because that is what `mode_t' will be widened to.
251
252 This function is a cancellation point and therefore not marked with
253 __THROW. */
254 #ifndef __USE_FILE_OFFSET64
255 extern int creat (const char *__file, mode_t __mode) __nonnull ((1));
256 #else
257 # ifdef __REDIRECT
258 extern int __REDIRECT (creat, (const char *__file, mode_t __mode),
259 creat64) __nonnull ((1));
260 # else
261 # define creat creat64
262 # endif
263 #endif
264 #ifdef __USE_LARGEFILE64
265 extern int creat64 (const char *__file, mode_t __mode) __nonnull ((1));
266 #endif
267
268 #if !defined F_LOCK && (defined __USE_MISC || (defined __USE_XOPEN_EXTENDED \
269 && !defined __USE_POSIX))
270 /* NOTE: These declarations also appear in <unistd.h>; be sure to keep both
271 files consistent. Some systems have them there and some here, and some
272 software depends on the macros being defined without including both. */
273
274 /* `lockf' is a simpler interface to the locking facilities of `fcntl'.
275 LEN is always relative to the current file position.
276 The CMD argument is one of the following. */
277
278 # define F_ULOCK 0 /* Unlock a previously locked region. */
279 # define F_LOCK 1 /* Lock a region for exclusive use. */
280 # define F_TLOCK 2 /* Test and lock a region for exclusive use. */
281 # define F_TEST 3 /* Test a region for other processes locks. */
282
283 # ifndef __USE_FILE_OFFSET64
284 extern int lockf (int __fd, int __cmd, off_t __len);
285 # else
286 # ifdef __REDIRECT
287 extern int __REDIRECT (lockf, (int __fd, int __cmd, __off64_t __len), lockf64);
288 # else
289 # define lockf lockf64
290 # endif
291 # endif
292 # ifdef __USE_LARGEFILE64
293 extern int lockf64 (int __fd, int __cmd, off64_t __len);
294 # endif
295 #endif
296
297 #ifdef __USE_XOPEN2K
298 /* Advice the system about the expected behaviour of the application with
299 respect to the file associated with FD. */
300 # ifndef __USE_FILE_OFFSET64
301 extern int posix_fadvise (int __fd, off_t __offset, off_t __len,
302 int __advise) __THROW;
303 # else
304 # ifdef __REDIRECT_NTH
305 extern int __REDIRECT_NTH (posix_fadvise, (int __fd, __off64_t __offset,
306 __off64_t __len, int __advise),
307 posix_fadvise64);
308 # else
309 # define posix_fadvise posix_fadvise64
310 # endif
311 # endif
312 # ifdef __USE_LARGEFILE64
313 extern int posix_fadvise64 (int __fd, off64_t __offset, off64_t __len,
314 int __advise) __THROW;
315 # endif
316
317
318 /* Reserve storage for the data of the file associated with FD.
319
320 This function is a possible cancellation point and therefore not
321 marked with __THROW. */
322 # ifndef __USE_FILE_OFFSET64
323 extern int posix_fallocate (int __fd, off_t __offset, off_t __len);
324 # else
325 # ifdef __REDIRECT
326 extern int __REDIRECT (posix_fallocate, (int __fd, __off64_t __offset,
327 __off64_t __len),
328 posix_fallocate64);
329 # else
330 # define posix_fallocate posix_fallocate64
331 # endif
332 # endif
333 # ifdef __USE_LARGEFILE64
334 extern int posix_fallocate64 (int __fd, off64_t __offset, off64_t __len);
335 # endif
336 #endif
337
338
339 /* Define some inlines helping to catch common problems. */
340 #if __USE_FORTIFY_LEVEL > 0 && defined __fortify_function \
341 && defined __va_arg_pack_len
342 # include <bits/fcntl2.h>
343 #endif
344
345 __END_DECLS
346
347 #endif /* fcntl.h */
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