1/* Copyright (C) 1991-2020 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/* Do the file control operation described by CMD on FD.
143 The remaining arguments are interpreted depending on CMD.
144
145 This function is a cancellation point and therefore not marked with
146 __THROW. */
147#ifndef __USE_FILE_OFFSET64
148extern int fcntl (int __fd, int __cmd, ...);
149#else
150# ifdef __REDIRECT
151extern int __REDIRECT (fcntl, (int __fd, int __cmd, ...), fcntl64);
152# else
153# define fcntl fcntl64
154# endif
155#endif
156#ifdef __USE_LARGEFILE64
157extern int fcntl64 (int __fd, int __cmd, ...);
158#endif
159
160/* Open FILE and return a new file descriptor for it, or -1 on error.
161 OFLAG determines the type of access used. If O_CREAT or O_TMPFILE is set
162 in OFLAG, the third argument is taken as a `mode_t', the mode of the
163 created file.
164
165 This function is a cancellation point and therefore not marked with
166 __THROW. */
167#ifndef __USE_FILE_OFFSET64
168extern int open (const char *__file, int __oflag, ...) __nonnull ((1));
169#else
170# ifdef __REDIRECT
171extern int __REDIRECT (open, (const char *__file, int __oflag, ...), open64)
172 __nonnull ((1));
173# else
174# define open open64
175# endif
176#endif
177#ifdef __USE_LARGEFILE64
178extern int open64 (const char *__file, int __oflag, ...) __nonnull ((1));
179#endif
180
181#ifdef __USE_ATFILE
182/* Similar to `open' but a relative path name is interpreted relative to
183 the directory for which FD is a descriptor.
184
185 NOTE: some other `openat' implementation support additional functionality
186 through this interface, especially using the O_XATTR flag. This is not
187 yet supported here.
188
189 This function is a cancellation point and therefore not marked with
190 __THROW. */
191# ifndef __USE_FILE_OFFSET64
192extern int openat (int __fd, const char *__file, int __oflag, ...)
193 __nonnull ((2));
194# else
195# ifdef __REDIRECT
196extern int __REDIRECT (openat, (int __fd, const char *__file, int __oflag,
197 ...), openat64) __nonnull ((2));
198# else
199# define openat openat64
200# endif
201# endif
202# ifdef __USE_LARGEFILE64
203extern int openat64 (int __fd, const char *__file, int __oflag, ...)
204 __nonnull ((2));
205# endif
206#endif
207
208/* Create and open FILE, with mode MODE. This takes an `int' MODE
209 argument because that is what `mode_t' will be widened to.
210
211 This function is a cancellation point and therefore not marked with
212 __THROW. */
213#ifndef __USE_FILE_OFFSET64
214extern int creat (const char *__file, mode_t __mode) __nonnull ((1));
215#else
216# ifdef __REDIRECT
217extern int __REDIRECT (creat, (const char *__file, mode_t __mode),
218 creat64) __nonnull ((1));
219# else
220# define creat creat64
221# endif
222#endif
223#ifdef __USE_LARGEFILE64
224extern int creat64 (const char *__file, mode_t __mode) __nonnull ((1));
225#endif
226
227#if !defined F_LOCK && (defined __USE_MISC || (defined __USE_XOPEN_EXTENDED \
228 && !defined __USE_POSIX))
229/* NOTE: These declarations also appear in <unistd.h>; be sure to keep both
230 files consistent. Some systems have them there and some here, and some
231 software depends on the macros being defined without including both. */
232
233/* `lockf' is a simpler interface to the locking facilities of `fcntl'.
234 LEN is always relative to the current file position.
235 The CMD argument is one of the following. */
236
237# define F_ULOCK 0 /* Unlock a previously locked region. */
238# define F_LOCK 1 /* Lock a region for exclusive use. */
239# define F_TLOCK 2 /* Test and lock a region for exclusive use. */
240# define F_TEST 3 /* Test a region for other processes locks. */
241
242# ifndef __USE_FILE_OFFSET64
243extern int lockf (int __fd, int __cmd, off_t __len);
244# else
245# ifdef __REDIRECT
246extern int __REDIRECT (lockf, (int __fd, int __cmd, __off64_t __len), lockf64);
247# else
248# define lockf lockf64
249# endif
250# endif
251# ifdef __USE_LARGEFILE64
252extern int lockf64 (int __fd, int __cmd, off64_t __len);
253# endif
254#endif
255
256#ifdef __USE_XOPEN2K
257/* Advice the system about the expected behaviour of the application with
258 respect to the file associated with FD. */
259# ifndef __USE_FILE_OFFSET64
260extern int posix_fadvise (int __fd, off_t __offset, off_t __len,
261 int __advise) __THROW;
262# else
263 # ifdef __REDIRECT_NTH
264extern int __REDIRECT_NTH (posix_fadvise, (int __fd, __off64_t __offset,
265 __off64_t __len, int __advise),
266 posix_fadvise64);
267# else
268# define posix_fadvise posix_fadvise64
269# endif
270# endif
271# ifdef __USE_LARGEFILE64
272extern int posix_fadvise64 (int __fd, off64_t __offset, off64_t __len,
273 int __advise) __THROW;
274# endif
275
276
277/* Reserve storage for the data of the file associated with FD.
278
279 This function is a possible cancellation point and therefore not
280 marked with __THROW. */
281# ifndef __USE_FILE_OFFSET64
282extern int posix_fallocate (int __fd, off_t __offset, off_t __len);
283# else
284 # ifdef __REDIRECT
285extern int __REDIRECT (posix_fallocate, (int __fd, __off64_t __offset,
286 __off64_t __len),
287 posix_fallocate64);
288# else
289# define posix_fallocate posix_fallocate64
290# endif
291# endif
292# ifdef __USE_LARGEFILE64
293extern int posix_fallocate64 (int __fd, off64_t __offset, off64_t __len);
294# endif
295#endif
296
297
298/* Define some inlines helping to catch common problems. */
299#if __USE_FORTIFY_LEVEL > 0 && defined __fortify_function \
300 && defined __va_arg_pack_len
301# include <bits/fcntl2.h>
302#endif
303
304__END_DECLS
305
306#endif /* fcntl.h */
307

source code of include/fcntl.h