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 the definitions of O_*, F_*, FD_*: all the
  31    numbers and flag bits for `open', `fcntl', et al.  */
  32 #include <bits/fcntl.h>
  33
  34 #if defined __USE_XOPEN || defined __USE_XOPEN2K
  35 /* The Single Unix specification says that some more types are
  36    available here.  */
  37 # ifndef __mode_t_defined
  38 typedef __mode_t mode_t;
  39 #  define __mode_t_defined
  40 # endif
  41
  42 # ifndef __off_t_defined
  43 #  ifndef __USE_FILE_OFFSET64
  44 typedef __off_t off_t;
  45 #  else
  46 typedef __off64_t off_t;
  47 #  endif
  48 #  define __off_t_defined
  49 # endif
  50
  51 # ifndef __pid_t_defined
  52 typedef __pid_t pid_t;
  53 #  define __pid_t_defined
  54 # endif
  55 #endif  /* X/Open */
  56
  57 /* For XPG all symbols from <sys/stat.h> should also be available.  */
  58 #if defined __USE_XOPEN || defined __USE_XOPEN2K8
  59 # include <bits/types.h>         /* For __mode_t and __dev_t.  */
  60 # define __need_timespec
  61 # include <time.h>
  62 # include <bits/stat.h>
  63
  64 # define S_IFMT         __S_IFMT
  65 # define S_IFDIR        __S_IFDIR
  66 # define S_IFCHR        __S_IFCHR
  67 # define S_IFBLK        __S_IFBLK
  68 # define S_IFREG        __S_IFREG
  69 # ifdef __S_IFIFO
  70 #  define S_IFIFO       __S_IFIFO
  71 # endif
  72 # ifdef __S_IFLNK
  73 #  define S_IFLNK       __S_IFLNK
  74 # endif
  75 # if (defined __USE_UNIX98 || defined __USE_XOPEN2K8) && defined __S_IFSOCK
  76 #  define S_IFSOCK      __S_IFSOCK
  77 # endif
  78
  79 /* Protection bits.  */
  80
  81 # define S_ISUID        __S_ISUID       /* Set user ID on execution.  */
  82 # define S_ISGID        __S_ISGID       /* Set group ID on execution.  */
  83
  84 # if defined __USE_BSD || defined __USE_MISC || defined __USE_XOPEN
  85 /* Save swapped text after use (sticky bit).  This is pretty well obsolete.  */
  86 #  define S_ISVTX       __S_ISVTX
  87 # endif
  88
  89 # define S_IRUSR        __S_IREAD       /* Read by owner.  */
  90 # define S_IWUSR        __S_IWRITE      /* Write by owner.  */
  91 # define S_IXUSR        __S_IEXEC       /* Execute by owner.  */
  92 /* Read, write, and execute by owner.  */
  93 # define S_IRWXU        (__S_IREAD|__S_IWRITE|__S_IEXEC)
  94
  95 # define S_IRGRP        (S_IRUSR >> 3)  /* Read by group.  */
  96 # define S_IWGRP        (S_IWUSR >> 3)  /* Write by group.  */
  97 # define S_IXGRP        (S_IXUSR >> 3)  /* Execute by group.  */
  98 /* Read, write, and execute by group.  */
  99 # define S_IRWXG        (S_IRWXU >> 3)
 100
 101 # define S_IROTH        (S_IRGRP >> 3)  /* Read by others.  */
 102 # define S_IWOTH        (S_IWGRP >> 3)  /* Write by others.  */
 103 # define S_IXOTH        (S_IXGRP >> 3)  /* Execute by others.  */
 104 /* Read, write, and execute by others.  */
 105 # define S_IRWXO        (S_IRWXG >> 3)
 106 #endif
 107
 108 #ifdef  __USE_MISC
 109 # ifndef R_OK                   /* Verbatim from <unistd.h>.  Ugh.  */
 110 /* Values for the second argument to access.
 111    These may be OR'd together.  */
 112 #  define R_OK  4               /* Test for read permission.  */
 113 #  define W_OK  2               /* Test for write permission.  */
 114 #  define X_OK  1               /* Test for execute permission.  */
 115 #  define F_OK  0               /* Test for existence.  */
 116 # endif
 117 #endif /* Use misc.  */
 118
 119 /* XPG wants the following symbols.   <stdio.h> has the same definitions.  */
 120 #if defined __USE_XOPEN || defined __USE_XOPEN2K8
 121 # define SEEK_SET       0       /* Seek from beginning of file.  */
 122 # define SEEK_CUR       1       /* Seek from current position.  */
 123 # define SEEK_END       2       /* Seek from end of file.  */
 124 #endif  /* XPG */
 125
 126 #ifdef __USE_ATFILE
 127 # define AT_FDCWD               -100    /* Special value used to indicate
 128                                            the *at functions should use the
 129                                            current working directory. */
 130 # define AT_SYMLINK_NOFOLLOW    0x100   /* Do not follow symbolic links.  */
 131 # define AT_REMOVEDIR           0x200   /* Remove directory instead of
 132                                            unlinking file.  */
 133 # define AT_SYMLINK_FOLLOW      0x400   /* Follow symbolic links.  */
 134 # ifdef __USE_GNU
 135 #  define AT_NO_AUTOMOUNT       0x800   /* Suppress terminal automount
 136                                            traversal.  */
 137 #  define AT_EMPTY_PATH         0x1000  /* Allow empty relative pathname.  */
 138 # endif
 139 # define AT_EACCESS             0x200   /* Test access permitted for
 140                                            effective IDs, not real IDs.  */
 141 #endif
 142
 143 /* Do the file control operation described by CMD on FD.
 144    The remaining arguments are interpreted depending on CMD.
 145
 146    This function is a cancellation point and therefore not marked with
 147    __THROW.  */
 148 extern int fcntl (int __fd, int __cmd, ...);
 149
 150 /* Open FILE and return a new file descriptor for it, or -1 on error.
 151    OFLAG determines the type of access used.  If O_CREAT is on OFLAG,
 152    the third argument is taken as a `mode_t', the mode of the created file.
 153
 154    This function is a cancellation point and therefore not marked with
 155    __THROW.  */
 156 #ifndef __USE_FILE_OFFSET64
 157 extern int open (const char *__file, int __oflag, ...) __nonnull ((1));
 158 #else
 159 # ifdef __REDIRECT
 160 extern int __REDIRECT (open, (const char *__file, int __oflag, ...), open64)
 161      __nonnull ((1));
 162 # else
 163 #  define open open64
 164 # endif
 165 #endif
 166 #ifdef __USE_LARGEFILE64
 167 extern int open64 (const char *__file, int __oflag, ...) __nonnull ((1));
 168 #endif
 169
 170 #ifdef __USE_ATFILE
 171 /* Similar to `open' but a relative path name is interpreted relative to
 172    the directory for which FD is a descriptor.
 173
 174    NOTE: some other `openat' implementation support additional functionality
 175    through this interface, especially using the O_XATTR flag.  This is not
 176    yet supported here.
 177
 178    This function is a cancellation point and therefore not marked with
 179    __THROW.  */
 180 # ifndef __USE_FILE_OFFSET64
 181 extern int openat (int __fd, const char *__file, int __oflag, ...)
 182      __nonnull ((2));
 183 # else
 184 #  ifdef __REDIRECT
 185 extern int __REDIRECT (openat, (int __fd, const char *__file, int __oflag,
 186                                 ...), openat64) __nonnull ((2));
 187 #  else
 188 #   define openat openat64
 189 #  endif
 190 # endif
 191 # ifdef __USE_LARGEFILE64
 192 extern int openat64 (int __fd, const char *__file, int __oflag, ...)
 193      __nonnull ((2));
 194 # endif
 195 #endif
 196
 197 /* Create and open FILE, with mode MODE.  This takes an `int' MODE
 198    argument because that is what `mode_t' will be widened to.
 199
 200    This function is a cancellation point and therefore not marked with
 201    __THROW.  */
 202 #ifndef __USE_FILE_OFFSET64
 203 extern int creat (const char *__file, __mode_t __mode) __nonnull ((1));
 204 #else
 205 # ifdef __REDIRECT
 206 extern int __REDIRECT (creat, (const char *__file, __mode_t __mode),
 207                        creat64) __nonnull ((1));
 208 # else
 209 #  define creat creat64
 210 # endif
 211 #endif
 212 #ifdef __USE_LARGEFILE64
 213 extern int creat64 (const char *__file, __mode_t __mode) __nonnull ((1));
 214 #endif
 215
 216 #if !defined F_LOCK && (defined __USE_MISC || (defined __USE_XOPEN_EXTENDED \
 217                                                && !defined __USE_POSIX))
 218 /* NOTE: These declarations also appear in <unistd.h>; be sure to keep both
 219    files consistent.  Some systems have them there and some here, and some
 220    software depends on the macros being defined without including both.  */
 221
 222 /* `lockf' is a simpler interface to the locking facilities of `fcntl'.
 223    LEN is always relative to the current file position.
 224    The CMD argument is one of the following.  */
 225
 226 # define F_ULOCK 0      /* Unlock a previously locked region.  */
 227 # define F_LOCK  1      /* Lock a region for exclusive use.  */
 228 # define F_TLOCK 2      /* Test and lock a region for exclusive use.  */
 229 # define F_TEST  3      /* Test a region for other processes locks.  */
 230
 231 # ifndef __USE_FILE_OFFSET64
 232 extern int lockf (int __fd, int __cmd, __off_t __len);
 233 # else
 234 #  ifdef __REDIRECT
 235 extern int __REDIRECT (lockf, (int __fd, int __cmd, __off64_t __len), lockf64);
 236 #  else
 237 #   define lockf lockf64
 238 #  endif
 239 # endif
 240 # ifdef __USE_LARGEFILE64
 241 extern int lockf64 (int __fd, int __cmd, __off64_t __len);
 242 # endif
 243 #endif
 244
 245 #ifdef __USE_XOPEN2K
 246 /* Advice the system about the expected behaviour of the application with
 247    respect to the file associated with FD.  */
 248 # ifndef __USE_FILE_OFFSET64
 249 extern int posix_fadvise (int __fd, __off_t __offset, __off_t __len,
 250                           int __advise) __THROW;
 251 # else
 252  # ifdef __REDIRECT_NTH
 253 extern int __REDIRECT_NTH (posix_fadvise, (int __fd, __off64_t __offset,
 254                                            __off64_t __len, int __advise),
 255                            posix_fadvise64);
 256 #  else
 257 #   define posix_fadvise posix_fadvise64
 258 #  endif
 259 # endif
 260 # ifdef __USE_LARGEFILE64
 261 extern int posix_fadvise64 (int __fd, __off64_t __offset, __off64_t __len,
 262                             int __advise) __THROW;
 263 # endif
 264
 265
 266 /* Reserve storage for the data of the file associated with FD.
 267
 268    This function is a possible cancellation point and therefore not
 269    marked with __THROW.  */
 270 # ifndef __USE_FILE_OFFSET64
 271 extern int posix_fallocate (int __fd, __off_t __offset, __off_t __len);
 272 # else
 273  # ifdef __REDIRECT
 274 extern int __REDIRECT (posix_fallocate, (int __fd, __off64_t __offset,
 275                                          __off64_t __len),
 276                        posix_fallocate64);
 277 #  else
 278 #   define posix_fallocate posix_fallocate64
 279 #  endif
 280 # endif
 281 # ifdef __USE_LARGEFILE64
 282 extern int posix_fallocate64 (int __fd, __off64_t __offset, __off64_t __len);
 283 # endif
 284 #endif
 285
 286
 287 /* Define some inlines helping to catch common problems.  */
 288 #if __USE_FORTIFY_LEVEL > 0 && defined __fortify_function \
 289     && defined __va_arg_pack_len
 290 # include <bits/fcntl2.h>
 291 #endif
 292
 293 __END_DECLS
 294
 295 #endif /* fcntl.h  */