1 /* Copyright (C) 1991-2021 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 (fcntl, (int __fd, int __request, ...), 191 __fcntl_time64) __THROW; 192 extern int __REDIRECT (fcntl64, (int __fd, int __request, ...), 193 __fcntl_time64) __THROW; 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 */ 348