1/* Copyright (C) 1991-2026 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
50typedef __mode_t mode_t;
51# define __mode_t_defined
52#endif
53
54#ifndef __off_t_defined
55# ifndef __USE_FILE_OFFSET64
56typedef __off_t off_t;
57# else
58typedef __off64_t off_t;
59# endif
60# define __off_t_defined
61#endif
62
63#if defined __USE_LARGEFILE64 && !defined __off64_t_defined
64typedef __off64_t off64_t;
65# define __off64_t_defined
66#endif
67
68#ifndef __pid_t_defined
69typedef __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
171/* zig patch: fcntl was a simple symbol until glibc 2.27 inclusive.
172 * glibc 2.28 onwards converted it to a macro when compiled with
173 * USE_LARGEFILE64. */
174#if (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 28) || __GLIBC__ > 2
175/* Do the file control operation described by CMD on FD.
176 The remaining arguments are interpreted depending on CMD.
177
178 This function is a cancellation point and therefore not marked with
179 __THROW. */
180#ifndef __USE_TIME64_REDIRECTS
181# ifndef __USE_FILE_OFFSET64
182extern int fcntl (int __fd, int __cmd, ...);
183# else
184# ifdef __REDIRECT
185extern int __REDIRECT (fcntl, (int __fd, int __cmd, ...), fcntl64);
186# else
187# define fcntl fcntl64
188# endif
189# endif
190# ifdef __USE_LARGEFILE64
191extern int fcntl64 (int __fd, int __cmd, ...);
192# endif
193#else /* __USE_TIME64_REDIRECTS */
194# ifdef __REDIRECT
195extern int __REDIRECT_NTH (fcntl, (int __fd, int __request, ...),
196 __fcntl_time64);
197extern int __REDIRECT_NTH (fcntl64, (int __fd, int __request, ...),
198 __fcntl_time64);
199# else
200extern int __fcntl_time64 (int __fd, int __request, ...) __THROW;
201# define fcntl64 __fcntl_time64
202# define fcntl __fcntl_time64
203# endif
204#endif
205#else /* glibc 2.27 or lower */
206extern int fcntl (int __fd, int __cmd, ...);
207#endif
208
209/* Open FILE and return a new file descriptor for it, or -1 on error.
210 OFLAG determines the type of access used. If O_CREAT or O_TMPFILE is set
211 in OFLAG, the third argument is taken as a `mode_t', the mode of the
212 created file.
213
214 This function is a cancellation point and therefore not marked with
215 __THROW. */
216#ifndef __USE_FILE_OFFSET64
217extern int open (const char *__file, int __oflag, ...) __nonnull ((1));
218#else
219# ifdef __REDIRECT
220extern int __REDIRECT (open, (const char *__file, int __oflag, ...), open64)
221 __nonnull ((1));
222# else
223# define open open64
224# endif
225#endif
226#ifdef __USE_LARGEFILE64
227extern int open64 (const char *__file, int __oflag, ...) __nonnull ((1));
228#endif
229
230#ifdef __USE_ATFILE
231/* Similar to `open' but a relative path name is interpreted relative to
232 the directory for which FD is a descriptor.
233
234 NOTE: some other `openat' implementation support additional functionality
235 through this interface, especially using the O_XATTR flag. This is not
236 yet supported here.
237
238 This function is a cancellation point and therefore not marked with
239 __THROW. */
240# ifndef __USE_FILE_OFFSET64
241extern int openat (int __fd, const char *__file, int __oflag, ...)
242 __nonnull ((2));
243# else
244# ifdef __REDIRECT
245extern int __REDIRECT (openat, (int __fd, const char *__file, int __oflag,
246 ...), openat64) __nonnull ((2));
247# else
248# define openat openat64
249# endif
250# endif
251# ifdef __USE_LARGEFILE64
252extern int openat64 (int __fd, const char *__file, int __oflag, ...)
253 __nonnull ((2));
254# endif
255#endif
256
257/* Create and open FILE, with mode MODE. This takes an `int' MODE
258 argument because that is what `mode_t' will be widened to.
259
260 This function is a cancellation point and therefore not marked with
261 __THROW. */
262#ifndef __USE_FILE_OFFSET64
263extern int creat (const char *__file, mode_t __mode) __nonnull ((1));
264#else
265# ifdef __REDIRECT
266extern int __REDIRECT (creat, (const char *__file, mode_t __mode),
267 creat64) __nonnull ((1));
268# else
269# define creat creat64
270# endif
271#endif
272#ifdef __USE_LARGEFILE64
273extern int creat64 (const char *__file, mode_t __mode) __nonnull ((1));
274#endif
275
276#if !defined F_LOCK && (defined __USE_MISC || (defined __USE_XOPEN_EXTENDED \
277 && !defined __USE_POSIX))
278/* NOTE: These declarations also appear in <unistd.h>; be sure to keep both
279 files consistent. Some systems have them there and some here, and some
280 software depends on the macros being defined without including both. */
281
282/* `lockf' is a simpler interface to the locking facilities of `fcntl'.
283 LEN is always relative to the current file position.
284 The CMD argument is one of the following. */
285
286# define F_ULOCK 0 /* Unlock a previously locked region. */
287# define F_LOCK 1 /* Lock a region for exclusive use. */
288# define F_TLOCK 2 /* Test and lock a region for exclusive use. */
289# define F_TEST 3 /* Test a region for other processes locks. */
290
291# ifndef __USE_FILE_OFFSET64
292extern int lockf (int __fd, int __cmd, off_t __len) __wur;
293# else
294# ifdef __REDIRECT
295extern int __REDIRECT (lockf, (int __fd, int __cmd, __off64_t __len),
296 lockf64) __wur;
297# else
298# define lockf lockf64
299# endif
300# endif
301# ifdef __USE_LARGEFILE64
302extern int lockf64 (int __fd, int __cmd, off64_t __len) __wur;
303# endif
304#endif
305
306#ifdef __USE_XOPEN2K
307/* Advice the system about the expected behaviour of the application with
308 respect to the file associated with FD. */
309# ifndef __USE_FILE_OFFSET64
310extern int posix_fadvise (int __fd, off_t __offset, off_t __len,
311 int __advise) __THROW;
312# else
313 # ifdef __REDIRECT_NTH
314extern int __REDIRECT_NTH (posix_fadvise, (int __fd, __off64_t __offset,
315 __off64_t __len, int __advise),
316 posix_fadvise64);
317# else
318# define posix_fadvise posix_fadvise64
319# endif
320# endif
321# ifdef __USE_LARGEFILE64
322extern int posix_fadvise64 (int __fd, off64_t __offset, off64_t __len,
323 int __advise) __THROW;
324# endif
325
326
327/* Reserve storage for the data of the file associated with FD.
328
329 This function is a possible cancellation point and therefore not
330 marked with __THROW. */
331# ifndef __USE_FILE_OFFSET64
332extern int posix_fallocate (int __fd, off_t __offset, off_t __len);
333# else
334 # ifdef __REDIRECT
335extern int __REDIRECT (posix_fallocate, (int __fd, __off64_t __offset,
336 __off64_t __len),
337 posix_fallocate64);
338# else
339# define posix_fallocate posix_fallocate64
340# endif
341# endif
342# ifdef __USE_LARGEFILE64
343extern int posix_fallocate64 (int __fd, off64_t __offset, off64_t __len);
344# endif
345#endif
346
347
348/* Define some inlines helping to catch common problems. */
349#if __USE_FORTIFY_LEVEL > 0 && defined __fortify_function
350# include <bits/fcntl2.h>
351#endif
352
353__END_DECLS
354
355#endif /* fcntl.h */