include/fcntl.h

   1 /* Copyright (C) 1991,1992,1994-2001,2003,2004,2005,2006,2007, 2009
   2         Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <http://www.gnu.org/licenses/>.  */
  18
  19 /*
  20  *      POSIX Standard: 6.5 File Control Operations     <fcntl.h>
  21  */
  22
  23 #ifndef _FCNTL_H
  24 #define _FCNTL_H        1
  25
  26 #include <features.h>
  27
  28 /* This must be early so <bits/fcntl.h> can define types winningly.  */
  29 __BEGIN_DECLS
  30
  31 /* Get the definitions of O_*, F_*, FD_*: all the
  32    numbers and flag bits for `open', `fcntl', et al.  */
  33 #include <bits/fcntl.h>
  34
  35 /* For XPG all symbols from <sys/stat.h> should also be available.  */
  36 #ifdef __USE_XOPEN
  37 # include <sys/stat.h>
  38 #endif
  39
  40 #ifdef  __USE_MISC
  41 # ifndef R_OK                   /* Verbatim from <unistd.h>.  Ugh.  */
  42 /* Values for the second argument to access.
  43    These may be OR'd together.  */
  44 #  define R_OK  4               /* Test for read permission.  */
  45 #  define W_OK  2               /* Test for write permission.  */
  46 #  define X_OK  1               /* Test for execute permission.  */
  47 #  define F_OK  0               /* Test for existence.  */
  48 # endif
  49 #endif /* Use misc.  */
  50
  51 /* XPG wants the following symbols.  */
  52 #ifdef __USE_XOPEN              /* <stdio.h> has the same definitions.  */
  53 # define SEEK_SET       0       /* Seek from beginning of file.  */
  54 # define SEEK_CUR       1       /* Seek from current position.  */
  55 # define SEEK_END       2       /* Seek from end of file.  */
  56 #endif  /* XPG */
  57
  58 #ifdef __USE_ATFILE
  59 # define AT_FDCWD               -100    /* Special value used to indicate
  60                                            the *at functions should use the
  61                                            current working directory. */
  62 # define AT_SYMLINK_NOFOLLOW    0x100   /* Do not follow symbolic links.  */
  63 # define AT_REMOVEDIR           0x200   /* Remove directory instead of
  64                                            unlinking file.  */
  65 # define AT_SYMLINK_FOLLOW      0x400   /* Follow symbolic links.  */
  66 # ifdef __USE_GNU
  67 #  define AT_NO_AUTOMOUNT       0x800   /* Suppress terminal automount
  68                                            traversal.  */
  69 #  define AT_EMPTY_PATH         0x1000  /* Allow empty relative pathname.  */
  70 # endif
  71 # define AT_EACCESS             0x200   /* Test access permitted for
  72                                            effective IDs, not real IDs.  */
  73 #endif
  74
  75 /* Do the file control operation described by CMD on FD.
  76    The remaining arguments are interpreted depending on CMD.
  77
  78    This function is a cancellation point and therefore not marked with
  79    __THROW.  */
  80 #if !defined(__USE_FILE_OFFSET64) || defined(__LP64__)
  81 extern int fcntl (int __fd, int __cmd, ...);
  82 # ifdef _LIBC
  83 extern int __fcntl_nocancel(int, int, long) attribute_hidden;
  84 libc_hidden_proto(fcntl)
  85 # endif
  86 #else
  87 # ifdef __REDIRECT
  88 extern int __REDIRECT (fcntl, (int __fd, int __cmd, ...), fcntl64);
  89 # else
  90 #  define fcntl fcntl64
  91 # endif
  92 #endif
  93 #if defined(__USE_LARGEFILE64) && !defined(__LP64__)
  94 extern int fcntl64 (int __fd, int __cmd, ...);
  95 # ifdef _LIBC
  96 extern int __fcntl64_nocancel(int, int, long) attribute_hidden;
  97 libc_hidden_proto(fcntl64)
  98 # endif
  99 #endif
 100
 101 /* Open FILE and return a new file descriptor for it, or -1 on error.
 102    OFLAG determines the type of access used.  If O_CREAT is on OFLAG,
 103    the third argument is taken as a `mode_t', the mode of the created file.
 104
 105    This function is a cancellation point and therefore not marked with
 106    __THROW.  */
 107 #ifndef __USE_FILE_OFFSET64
 108 extern int open (const char *__file, int __oflag, ...) __nonnull ((1));
 109 libc_hidden_proto(open)
 110 # ifdef _LIBC
 111 extern int __open2_nocancel(const char *, int) __nonnull ((1)) attribute_hidden;
 112 extern int __open_nocancel(const char *, int, mode_t) __nonnull ((1)) attribute_hidden;
 113 # endif
 114 #else
 115 # ifdef __REDIRECT
 116 extern int __REDIRECT (open, (const char *__file, int __oflag, ...), open64)
 117      __nonnull ((1));
 118 # else
 119 #  define open open64
 120 # endif
 121 #endif
 122 #ifdef __USE_LARGEFILE64
 123 extern int open64 (const char *__file, int __oflag, ...) __nonnull ((1));
 124 libc_hidden_proto(open64)
 125 #endif
 126
 127 #ifdef __USE_ATFILE
 128 /* Similar to `open' but a relative path name is interpreted relative to
 129    the directory for which FD is a descriptor.
 130
 131    NOTE: some other `openat' implementation support additional functionality
 132    through this interface, especially using the O_XATTR flag.  This is not
 133    yet supported here.
 134
 135    This function is a cancellation point and therefore not marked with
 136    __THROW.  */
 137 # ifndef __USE_FILE_OFFSET64
 138 extern int openat (int __fd, const char *__file, int __oflag, ...)
 139      __nonnull ((2));
 140 libc_hidden_proto(openat)
 141 # else
 142 #  ifdef __REDIRECT
 143 extern int __REDIRECT (openat, (int __fd, const char *__file, int __oflag,
 144                                 ...), openat64) __nonnull ((2));
 145 #  else
 146 #   define openat openat64
 147 #  endif
 148 # endif
 149
 150 extern int openat64 (int __fd, const char *__file, int __oflag, ...)
 151      __nonnull ((2));
 152 #endif
 153
 154 /* Create and open FILE, with mode MODE.  This takes an `int' MODE
 155    argument because that is what `mode_t' will be widened to.
 156
 157    This function is a cancellation point and therefore not marked with
 158    __THROW.  */
 159 #ifndef __USE_FILE_OFFSET64
 160 extern int creat (const char *__file, __mode_t __mode) __nonnull ((1));
 161 #else
 162 # ifdef __REDIRECT
 163 extern int __REDIRECT (creat, (const char *__file, __mode_t __mode),
 164                        creat64) __nonnull ((1));
 165 # else
 166 #  define creat creat64
 167 # endif
 168 #endif
 169 #ifdef __USE_LARGEFILE64
 170 extern int creat64 (const char *__file, __mode_t __mode) __nonnull ((1));
 171 #endif
 172
 173 #if !defined F_LOCK && (defined __USE_MISC || (defined __USE_XOPEN_EXTENDED \
 174                                                && !defined __USE_POSIX))
 175 /* NOTE: These declarations also appear in <unistd.h>; be sure to keep both
 176    files consistent.  Some systems have them there and some here, and some
 177    software depends on the macros being defined without including both.  */
 178
 179 /* `lockf' is a simpler interface to the locking facilities of `fcntl'.
 180    LEN is always relative to the current file position.
 181    The CMD argument is one of the following.  */
 182
 183 # define F_ULOCK 0      /* Unlock a previously locked region.  */
 184 # define F_LOCK  1      /* Lock a region for exclusive use.  */
 185 # define F_TLOCK 2      /* Test and lock a region for exclusive use.  */
 186 # define F_TEST  3      /* Test a region for other processes locks.  */
 187
 188 # ifndef __USE_FILE_OFFSET64
 189 extern int lockf (int __fd, int __cmd, __off_t __len);
 190 libc_hidden_proto(lockf)
 191 # else
 192 #  ifdef __REDIRECT
 193 extern int __REDIRECT (lockf, (int __fd, int __cmd, __off64_t __len), lockf64);
 194 #  else
 195 #   define lockf lockf64
 196 #  endif
 197 # endif
 198 # ifdef __USE_LARGEFILE64
 199 extern int lockf64 (int __fd, int __cmd, __off64_t __len);
 200 # endif
 201 #endif
 202
 203 #if defined __USE_XOPEN2K && defined __UCLIBC_HAS_ADVANCED_REALTIME__
 204 /* Advice the system about the expected behaviour of the application with
 205    respect to the file associated with FD.  */
 206 # ifndef __USE_FILE_OFFSET64
 207 extern int posix_fadvise (int __fd, __off_t __offset, __off_t __len,
 208                           int __advise) __THROW;
 209 # else
 210 #  ifdef __REDIRECT_NTH
 211 extern int __REDIRECT_NTH (posix_fadvise, (int __fd, __off64_t __offset,
 212                                            __off64_t __len, int __advise),
 213                            posix_fadvise64);
 214 #  else
 215 #   define posix_fadvise posix_fadvise64
 216 #  endif
 217 # endif
 218 # ifdef __USE_LARGEFILE64
 219 extern int posix_fadvise64 (int __fd, __off64_t __offset, __off64_t __len,
 220                             int __advise) __THROW;
 221 # endif
 222
 223 #endif
 224
 225 #if defined __UCLIBC_HAS_ADVANCED_REALTIME__
 226
 227 /* Reserve storage for the data of the file associated with FD.
 228
 229    This function is a possible cancellation point and therefore not
 230    marked with __THROW.  */
 231 # ifndef __USE_FILE_OFFSET64
 232 extern int posix_fallocate (int __fd, __off_t __offset, __off_t __len);
 233 # else
 234 #  ifdef __REDIRECT
 235 extern int __REDIRECT (posix_fallocate, (int __fd, __off64_t __offset,
 236                                          __off64_t __len),
 237                        posix_fallocate64);
 238 #  else
 239 #   define posix_fallocate posix_fallocate64
 240 #  endif
 241 # endif
 242 # ifdef __USE_LARGEFILE64
 243 extern int posix_fallocate64 (int __fd, __off64_t __offset, __off64_t __len);
 244 # endif
 245 #endif
 246
 247 #if (defined __UCLIBC_LINUX_SPECIFIC__ && defined __USE_GNU) || defined _LIBC
 248 /* Reserve storage for the data of a file associated with FD.  This function
 249    is Linux-specific.  For the portable version, use posix_fallocate().
 250    Unlike the latter, fallocate can operate in different modes.  The default
 251    mode = 0 is equivalent to posix_fallocate().
 252
 253    Note: These declarations are used in posix_fallocate.c and
 254    posix_fallocate64.c, so we expose them internally.
 255  */
 256
 257 /* Flags for fallocate's mode.  */
 258 # define FALLOC_FL_KEEP_SIZE            1 /* Don't extend size of file
 259                                              even if offset + len is
 260                                              greater than file size.  */
 261 # define FALLOC_FL_PUNCH_HOLE           2 /* Create a hole in the file.  */
 262
 263 # ifndef __USE_FILE_OFFSET64
 264 extern int fallocate (int __fd, int __mode, __off_t __offset, __off_t __len);
 265 # else
 266 #  ifdef __REDIRECT
 267 extern int __REDIRECT (fallocate, (int __fd, int __mode, __off64_t __offset,
 268                                    __off64_t __len),
 269                        fallocate64);
 270 #  else
 271 #   define fallocate fallocate64
 272 #  endif
 273 # endif
 274 # ifdef __USE_LARGEFILE64
 275 extern int fallocate64 (int __fd, int __mode, __off64_t __offset, __off64_t __len);
 276 # endif
 277 #endif
 278
 279 __END_DECLS
 280
 281 #endif /* fcntl.h  */