1/* Copyright (C) 1991-2016 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 <http://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# define __need_timespec
76# include <time.h>
77#endif
78#if defined __USE_XOPEN || defined __USE_XOPEN2K8
79# include <bits/stat.h>
80
81# define S_IFMT __S_IFMT
82# define S_IFDIR __S_IFDIR
83# define S_IFCHR __S_IFCHR
84# define S_IFBLK __S_IFBLK
85# define S_IFREG __S_IFREG
86# ifdef __S_IFIFO
87# define S_IFIFO __S_IFIFO
88# endif
89# ifdef __S_IFLNK
90# define S_IFLNK __S_IFLNK
91# endif
92# if (defined __USE_UNIX98 || defined __USE_XOPEN2K8) && defined __S_IFSOCK
93# define S_IFSOCK __S_IFSOCK
94# endif
95
96/* Protection bits. */
97
98# define S_ISUID __S_ISUID /* Set user ID on execution. */
99# define S_ISGID __S_ISGID /* Set group ID on execution. */
100
101# if defined __USE_MISC || defined __USE_XOPEN
102/* Save swapped text after use (sticky bit). This is pretty well obsolete. */
103# define S_ISVTX __S_ISVTX
104# endif
105
106# define S_IRUSR __S_IREAD /* Read by owner. */
107# define S_IWUSR __S_IWRITE /* Write by owner. */
108# define S_IXUSR __S_IEXEC /* Execute by owner. */
109/* Read, write, and execute by owner. */
110# define S_IRWXU (__S_IREAD|__S_IWRITE|__S_IEXEC)
111
112# define S_IRGRP (S_IRUSR >> 3) /* Read by group. */
113# define S_IWGRP (S_IWUSR >> 3) /* Write by group. */
114# define S_IXGRP (S_IXUSR >> 3) /* Execute by group. */
115/* Read, write, and execute by group. */
116# define S_IRWXG (S_IRWXU >> 3)
117
118# define S_IROTH (S_IRGRP >> 3) /* Read by others. */
119# define S_IWOTH (S_IWGRP >> 3) /* Write by others. */
120# define S_IXOTH (S_IXGRP >> 3) /* Execute by others. */
121/* Read, write, and execute by others. */
122# define S_IRWXO (S_IRWXG >> 3)
123#endif
124
125#ifdef __USE_MISC
126# ifndef R_OK /* Verbatim from <unistd.h>. Ugh. */
127/* Values for the second argument to access.
128 These may be OR'd together. */
129# define R_OK 4 /* Test for read permission. */
130# define W_OK 2 /* Test for write permission. */
131# define X_OK 1 /* Test for execute permission. */
132# define F_OK 0 /* Test for existence. */
133# endif
134#endif /* Use misc. */
135
136/* XPG wants the following symbols. <stdio.h> has the same definitions. */
137#if defined __USE_XOPEN || defined __USE_XOPEN2K8
138# define SEEK_SET 0 /* Seek from beginning of file. */
139# define SEEK_CUR 1 /* Seek from current position. */
140# define SEEK_END 2 /* Seek from end of file. */
141#endif /* XPG */
142
143/* The constants AT_REMOVEDIR and AT_EACCESS have the same value. AT_EASSESS
144 is meaningful only to faccessat, while AT_REMOVEDIR is meaningful only to
145 unlinkat. The two functions do completely different things and therefore,
146 the flags can be allowed to overlap. For example, passing AT_REMOVEDIR to
147 faccessat would be undefined behavior and thus treating it equivalent to
148 AT_EACCESS is valid undefined behavior. */
149#ifdef __USE_ATFILE
150# define AT_FDCWD -100 /* Special value used to indicate
151 the *at functions should use the
152 current working directory. */
153# define AT_SYMLINK_NOFOLLOW 0x100 /* Do not follow symbolic links. */
154# define AT_REMOVEDIR 0x200 /* Remove directory instead of
155 unlinking file. */
156# define AT_SYMLINK_FOLLOW 0x400 /* Follow symbolic links. */
157# ifdef __USE_GNU
158# define AT_NO_AUTOMOUNT 0x800 /* Suppress terminal automount
159 traversal. */
160# define AT_EMPTY_PATH 0x1000 /* Allow empty relative pathname. */
161# endif
162# define AT_EACCESS 0x200 /* Test access permitted for
163 effective IDs, not real IDs. */
164#endif
165
166/* Do the file control operation described by CMD on FD.
167 The remaining arguments are interpreted depending on CMD.
168
169 This function is a cancellation point and therefore not marked with
170 __THROW. */
171extern int fcntl (int __fd, int __cmd, ...);
172
173/* Open FILE and return a new file descriptor for it, or -1 on error.
174 OFLAG determines the type of access used. If O_CREAT or O_TMPFILE is set
175 in OFLAG, the third argument is taken as a `mode_t', the mode of the
176 created file.
177
178 This function is a cancellation point and therefore not marked with
179 __THROW. */
180#ifndef __USE_FILE_OFFSET64
181extern int open (const char *__file, int __oflag, ...) __nonnull ((1));
182#else
183# ifdef __REDIRECT
184extern int __REDIRECT (open, (const char *__file, int __oflag, ...), open64)
185 __nonnull ((1));
186# else
187# define open open64
188# endif
189#endif
190#ifdef __USE_LARGEFILE64
191extern int open64 (const char *__file, int __oflag, ...) __nonnull ((1));
192#endif
193
194#ifdef __USE_ATFILE
195/* Similar to `open' but a relative path name is interpreted relative to
196 the directory for which FD is a descriptor.
197
198 NOTE: some other `openat' implementation support additional functionality
199 through this interface, especially using the O_XATTR flag. This is not
200 yet supported here.
201
202 This function is a cancellation point and therefore not marked with
203 __THROW. */
204# ifndef __USE_FILE_OFFSET64
205extern int openat (int __fd, const char *__file, int __oflag, ...)
206 __nonnull ((2));
207# else
208# ifdef __REDIRECT
209extern int __REDIRECT (openat, (int __fd, const char *__file, int __oflag,
210 ...), openat64) __nonnull ((2));
211# else
212# define openat openat64
213# endif
214# endif
215# ifdef __USE_LARGEFILE64
216extern int openat64 (int __fd, const char *__file, int __oflag, ...)
217 __nonnull ((2));
218# endif
219#endif
220
221/* Create and open FILE, with mode MODE. This takes an `int' MODE
222 argument because that is what `mode_t' will be widened to.
223
224 This function is a cancellation point and therefore not marked with
225 __THROW. */
226#ifndef __USE_FILE_OFFSET64
227extern int creat (const char *__file, mode_t __mode) __nonnull ((1));
228#else
229# ifdef __REDIRECT
230extern int __REDIRECT (creat, (const char *__file, mode_t __mode),
231 creat64) __nonnull ((1));
232# else
233# define creat creat64
234# endif
235#endif
236#ifdef __USE_LARGEFILE64
237extern int creat64 (const char *__file, mode_t __mode) __nonnull ((1));
238#endif
239
240#if !defined F_LOCK && (defined __USE_MISC || (defined __USE_XOPEN_EXTENDED \
241 && !defined __USE_POSIX))
242/* NOTE: These declarations also appear in <unistd.h>; be sure to keep both
243 files consistent. Some systems have them there and some here, and some
244 software depends on the macros being defined without including both. */
245
246/* `lockf' is a simpler interface to the locking facilities of `fcntl'.
247 LEN is always relative to the current file position.
248 The CMD argument is one of the following. */
249
250# define F_ULOCK 0 /* Unlock a previously locked region. */
251# define F_LOCK 1 /* Lock a region for exclusive use. */
252# define F_TLOCK 2 /* Test and lock a region for exclusive use. */
253# define F_TEST 3 /* Test a region for other processes locks. */
254
255# ifndef __USE_FILE_OFFSET64
256extern int lockf (int __fd, int __cmd, off_t __len);
257# else
258# ifdef __REDIRECT
259extern int __REDIRECT (lockf, (int __fd, int __cmd, __off64_t __len), lockf64);
260# else
261# define lockf lockf64
262# endif
263# endif
264# ifdef __USE_LARGEFILE64
265extern int lockf64 (int __fd, int __cmd, off64_t __len);
266# endif
267#endif
268
269#ifdef __USE_XOPEN2K
270/* Advice the system about the expected behaviour of the application with
271 respect to the file associated with FD. */
272# ifndef __USE_FILE_OFFSET64
273extern int posix_fadvise (int __fd, off_t __offset, off_t __len,
274 int __advise) __THROW;
275# else
276 # ifdef __REDIRECT_NTH
277extern int __REDIRECT_NTH (posix_fadvise, (int __fd, __off64_t __offset,
278 __off64_t __len, int __advise),
279 posix_fadvise64);
280# else
281# define posix_fadvise posix_fadvise64
282# endif
283# endif
284# ifdef __USE_LARGEFILE64
285extern int posix_fadvise64 (int __fd, off64_t __offset, off64_t __len,
286 int __advise) __THROW;
287# endif
288
289
290/* Reserve storage for the data of the file associated with FD.
291
292 This function is a possible cancellation point and therefore not
293 marked with __THROW. */
294# ifndef __USE_FILE_OFFSET64
295extern int posix_fallocate (int __fd, off_t __offset, off_t __len);
296# else
297 # ifdef __REDIRECT
298extern int __REDIRECT (posix_fallocate, (int __fd, __off64_t __offset,
299 __off64_t __len),
300 posix_fallocate64);
301# else
302# define posix_fallocate posix_fallocate64
303# endif
304# endif
305# ifdef __USE_LARGEFILE64
306extern int posix_fallocate64 (int __fd, off64_t __offset, off64_t __len);
307# endif
308#endif
309
310
311/* Define some inlines helping to catch common problems. */
312#if __USE_FORTIFY_LEVEL > 0 && defined __fortify_function \
313 && defined __va_arg_pack_len
314# include <bits/fcntl2.h>
315#endif
316
317__END_DECLS
318
319#endif /* fcntl.h */
320