io/fcntl.h

   1 /* Copyright (C) 1991-2012 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 #if defined __USE_XOPEN || defined __USE_XOPEN2K
  38 /* The Single Unix specification says that some more types are
  39    available here.  */
  40 # ifndef __mode_t_defined
  41 typedef __mode_t mode_t;
  42 #  define __mode_t_defined
  43 # endif
  44
  45 # ifndef __off_t_defined
  46 #  ifndef __USE_FILE_OFFSET64
  47 typedef __off_t off_t;
  48 #  else
  49 typedef __off64_t off_t;
  50 #  endif
  51 #  define __off_t_defined
  52 # endif
  53
  54 # ifndef __pid_t_defined
  55 typedef __pid_t pid_t;
  56 #  define __pid_t_defined
  57 # endif
  58 #endif  /* X/Open */
  59
  60 /* For XPG all symbols from <sys/stat.h> should also be available.  */
  61 #if defined __USE_XOPEN || defined __USE_XOPEN2K8
  62 # define __need_timespec
  63 # include <time.h>
  64 # include <bits/stat.h>
  65
  66 # define S_IFMT         __S_IFMT
  67 # define S_IFDIR        __S_IFDIR
  68 # define S_IFCHR        __S_IFCHR
  69 # define S_IFBLK        __S_IFBLK
  70 # define S_IFREG        __S_IFREG
  71 # ifdef __S_IFIFO
  72 #  define S_IFIFO       __S_IFIFO
  73 # endif
  74 # ifdef __S_IFLNK
  75 #  define S_IFLNK       __S_IFLNK
  76 # endif
  77 # if (defined __USE_UNIX98 || defined __USE_XOPEN2K8) && defined __S_IFSOCK
  78 #  define S_IFSOCK      __S_IFSOCK
  79 # endif
  80
  81 /* Protection bits.  */
  82
  83 # define S_ISUID        __S_ISUID       /* Set user ID on execution.  */
  84 # define S_ISGID        __S_ISGID       /* Set group ID on execution.  */
  85
  86 # if defined __USE_BSD || defined __USE_MISC || defined __USE_XOPEN
  87 /* Save swapped text after use (sticky bit).  This is pretty well obsolete.  */
  88 #  define S_ISVTX       __S_ISVTX
  89 # endif
  90
  91 # define S_IRUSR        __S_IREAD       /* Read by owner.  */
  92 # define S_IWUSR        __S_IWRITE      /* Write by owner.  */
  93 # define S_IXUSR        __S_IEXEC       /* Execute by owner.  */
  94 /* Read, write, and execute by owner.  */
  95 # define S_IRWXU        (__S_IREAD|__S_IWRITE|__S_IEXEC)
  96
  97 # define S_IRGRP        (S_IRUSR >> 3)  /* Read by group.  */
  98 # define S_IWGRP        (S_IWUSR >> 3)  /* Write by group.  */
  99 # define S_IXGRP        (S_IXUSR >> 3)  /* Execute by group.  */
 100 /* Read, write, and execute by group.  */
 101 # define S_IRWXG        (S_IRWXU >> 3)
 102
 103 # define S_IROTH        (S_IRGRP >> 3)  /* Read by others.  */
 104 # define S_IWOTH        (S_IWGRP >> 3)  /* Write by others.  */
 105 # define S_IXOTH        (S_IXGRP >> 3)  /* Execute by others.  */
 106 /* Read, write, and execute by others.  */
 107 # define S_IRWXO        (S_IRWXG >> 3)
 108 #endif
 109
 110 #ifdef  __USE_MISC
 111 # ifndef R_OK                   /* Verbatim from <unistd.h>.  Ugh.  */
 112 /* Values for the second argument to access.
 113    These may be OR'd together.  */
 114 #  define R_OK  4               /* Test for read permission.  */
 115 #  define W_OK  2               /* Test for write permission.  */
 116 #  define X_OK  1               /* Test for execute permission.  */
 117 #  define F_OK  0               /* Test for existence.  */
 118 # endif
 119 #endif /* Use misc.  */
 120
 121 /* XPG wants the following symbols.   <stdio.h> has the same definitions.  */
 122 #if defined __USE_XOPEN || defined __USE_XOPEN2K8
 123 # define SEEK_SET       0       /* Seek from beginning of file.  */
 124 # define SEEK_CUR       1       /* Seek from current position.  */
 125 # define SEEK_END       2       /* Seek from end of file.  */
 126 #endif  /* XPG */
 127
 128 #ifdef __USE_ATFILE
 129 # define AT_FDCWD               -100    /* Special value used to indicate
 130                                            the *at functions should use the
 131                                            current working directory. */
 132 # define AT_SYMLINK_NOFOLLOW    0x100   /* Do not follow symbolic links.  */
 133 # define AT_REMOVEDIR           0x200   /* Remove directory instead of
 134                                            unlinking file.  */
 135 # define AT_SYMLINK_FOLLOW      0x400   /* Follow symbolic links.  */
 136 # ifdef __USE_GNU
 137 #  define AT_NO_AUTOMOUNT       0x800   /* Suppress terminal automount
 138                                            traversal.  */
 139 #  define AT_EMPTY_PATH         0x1000  /* Allow empty relative pathname.  */
 140 # endif
 141 # define AT_EACCESS             0x200   /* Test access permitted for
 142                                            effective IDs, not real IDs.  */
 143 #endif
 144
 145 /* Do the file control operation described by CMD on FD.
 146    The remaining arguments are interpreted depending on CMD.
 147
 148    This function is a cancellation point and therefore not marked with
 149    __THROW.  */
 150 extern int fcntl (int __fd, int __cmd, ...);
 151
 152 /* Open FILE and return a new file descriptor for it, or -1 on error.
 153    OFLAG determines the type of access used.  If O_CREAT is on OFLAG,
 154    the third argument is taken as a `mode_t', the mode of the created file.
 155
 156    This function is a cancellation point and therefore not marked with
 157    __THROW.  */
 158 #ifndef __USE_FILE_OFFSET64
 159 extern int open (const char *__file, int __oflag, ...) __nonnull ((1));
 160 #else
 161 # ifdef __REDIRECT
 162 extern int __REDIRECT (open, (const char *__file, int __oflag, ...), open64)
 163      __nonnull ((1));
 164 # else
 165 #  define open open64
 166 # endif
 167 #endif
 168 #ifdef __USE_LARGEFILE64
 169 extern int open64 (const char *__file, int __oflag, ...) __nonnull ((1));
 170 #endif
 171
 172 #ifdef __USE_ATFILE
 173 /* Similar to `open' but a relative path name is interpreted relative to
 174    the directory for which FD is a descriptor.
 175
 176    NOTE: some other `openat' implementation support additional functionality
 177    through this interface, especially using the O_XATTR flag.  This is not
 178    yet supported here.
 179
 180    This function is a cancellation point and therefore not marked with
 181    __THROW.  */
 182 # ifndef __USE_FILE_OFFSET64
 183 extern int openat (int __fd, const char *__file, int __oflag, ...)
 184      __nonnull ((2));
 185 # else
 186 #  ifdef __REDIRECT
 187 extern int __REDIRECT (openat, (int __fd, const char *__file, int __oflag,
 188                                 ...), openat64) __nonnull ((2));
 189 #  else
 190 #   define openat openat64
 191 #  endif
 192 # endif
 193 # ifdef __USE_LARGEFILE64
 194 extern int openat64 (int __fd, const char *__file, int __oflag, ...)
 195      __nonnull ((2));
 196 # endif
 197 #endif
 198
 199 /* Create and open FILE, with mode MODE.  This takes an `int' MODE
 200    argument because that is what `mode_t' will be widened to.
 201
 202    This function is a cancellation point and therefore not marked with
 203    __THROW.  */
 204 #ifndef __USE_FILE_OFFSET64
 205 extern int creat (const char *__file, __mode_t __mode) __nonnull ((1));
 206 #else
 207 # ifdef __REDIRECT
 208 extern int __REDIRECT (creat, (const char *__file, __mode_t __mode),
 209                        creat64) __nonnull ((1));
 210 # else
 211 #  define creat creat64
 212 # endif
 213 #endif
 214 #ifdef __USE_LARGEFILE64
 215 extern int creat64 (const char *__file, __mode_t __mode) __nonnull ((1));
 216 #endif
 217
 218 #if !defined F_LOCK && (defined __USE_MISC || (defined __USE_XOPEN_EXTENDED \
 219                                                && !defined __USE_POSIX))
 220 /* NOTE: These declarations also appear in <unistd.h>; be sure to keep both
 221    files consistent.  Some systems have them there and some here, and some
 222    software depends on the macros being defined without including both.  */
 223
 224 /* `lockf' is a simpler interface to the locking facilities of `fcntl'.
 225    LEN is always relative to the current file position.
 226    The CMD argument is one of the following.  */
 227
 228 # define F_ULOCK 0      /* Unlock a previously locked region.  */
 229 # define F_LOCK  1      /* Lock a region for exclusive use.  */
 230 # define F_TLOCK 2      /* Test and lock a region for exclusive use.  */
 231 # define F_TEST  3      /* Test a region for other processes locks.  */
 232
 233 # ifndef __USE_FILE_OFFSET64
 234 extern int lockf (int __fd, int __cmd, __off_t __len);
 235 # else
 236 #  ifdef __REDIRECT
 237 extern int __REDIRECT (lockf, (int __fd, int __cmd, __off64_t __len), lockf64);
 238 #  else
 239 #   define lockf lockf64
 240 #  endif
 241 # endif
 242 # ifdef __USE_LARGEFILE64
 243 extern int lockf64 (int __fd, int __cmd, __off64_t __len);
 244 # endif
 245 #endif
 246
 247 #ifdef __USE_XOPEN2K
 248 /* Advice the system about the expected behaviour of the application with
 249    respect to the file associated with FD.  */
 250 # ifndef __USE_FILE_OFFSET64
 251 extern int posix_fadvise (int __fd, __off_t __offset, __off_t __len,
 252                           int __advise) __THROW;
 253 # else
 254  # ifdef __REDIRECT_NTH
 255 extern int __REDIRECT_NTH (posix_fadvise, (int __fd, __off64_t __offset,
 256                                            __off64_t __len, int __advise),
 257                            posix_fadvise64);
 258 #  else
 259 #   define posix_fadvise posix_fadvise64
 260 #  endif
 261 # endif
 262 # ifdef __USE_LARGEFILE64
 263 extern int posix_fadvise64 (int __fd, __off64_t __offset, __off64_t __len,
 264                             int __advise) __THROW;
 265 # endif
 266
 267
 268 /* Reserve storage for the data of the file associated with FD.
 269
 270    This function is a possible cancellation point and therefore not
 271    marked with __THROW.  */
 272 # ifndef __USE_FILE_OFFSET64
 273 extern int posix_fallocate (int __fd, __off_t __offset, __off_t __len);
 274 # else
 275  # ifdef __REDIRECT
 276 extern int __REDIRECT (posix_fallocate, (int __fd, __off64_t __offset,
 277                                          __off64_t __len),
 278                        posix_fallocate64);
 279 #  else
 280 #   define posix_fallocate posix_fallocate64
 281 #  endif
 282 # endif
 283 # ifdef __USE_LARGEFILE64
 284 extern int posix_fallocate64 (int __fd, __off64_t __offset, __off64_t __len);
 285 # endif
 286 #endif
 287
 288
 289 /* Define some inlines helping to catch common problems.  */
 290 #if __USE_FORTIFY_LEVEL > 0 && defined __fortify_function \
 291     && defined __va_arg_pack_len
 292 # include <bits/fcntl2.h>
 293 #endif
 294
 295 __END_DECLS
 296
 297 #endif /* fcntl.h  */