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