io/fcntl.h

   1 /* Copyright (C) 1991,1992,1994-2001,2003-2007,2009-2011,2012
   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 #if defined __USE_XOPEN || defined __USE_XOPEN2K8
  37 # include <bits/types.h>         /* For __mode_t and __dev_t.  */
  38 # define __need_timespec
  39 # include <time.h>
  40 # include <bits/stat.h>
  41
  42 # define S_IFMT         __S_IFMT
  43 # define S_IFDIR        __S_IFDIR
  44 # define S_IFCHR        __S_IFCHR
  45 # define S_IFBLK        __S_IFBLK
  46 # define S_IFREG        __S_IFREG
  47 # ifdef __S_IFIFO
  48 #  define S_IFIFO       __S_IFIFO
  49 # endif
  50 # ifdef __S_IFLNK
  51 #  define S_IFLNK       __S_IFLNK
  52 # endif
  53 # if (defined __USE_UNIX98 || defined __USE_XOPEN2K8) && defined __S_IFSOCK
  54 #  define S_IFSOCK      __S_IFSOCK
  55 # endif
  56
  57 /* Protection bits.  */
  58
  59 # define S_ISUID        __S_ISUID       /* Set user ID on execution.  */
  60 # define S_ISGID        __S_ISGID       /* Set group ID on execution.  */
  61
  62 # if defined __USE_BSD || defined __USE_MISC || defined __USE_XOPEN
  63 /* Save swapped text after use (sticky bit).  This is pretty well obsolete.  */
  64 #  define S_ISVTX       __S_ISVTX
  65 # endif
  66
  67 # define S_IRUSR        __S_IREAD       /* Read by owner.  */
  68 # define S_IWUSR        __S_IWRITE      /* Write by owner.  */
  69 # define S_IXUSR        __S_IEXEC       /* Execute by owner.  */
  70 /* Read, write, and execute by owner.  */
  71 # define S_IRWXU        (__S_IREAD|__S_IWRITE|__S_IEXEC)
  72
  73 # define S_IRGRP        (S_IRUSR >> 3)  /* Read by group.  */
  74 # define S_IWGRP        (S_IWUSR >> 3)  /* Write by group.  */
  75 # define S_IXGRP        (S_IXUSR >> 3)  /* Execute by group.  */
  76 /* Read, write, and execute by group.  */
  77 # define S_IRWXG        (S_IRWXU >> 3)
  78
  79 # define S_IROTH        (S_IRGRP >> 3)  /* Read by others.  */
  80 # define S_IWOTH        (S_IWGRP >> 3)  /* Write by others.  */
  81 # define S_IXOTH        (S_IXGRP >> 3)  /* Execute by others.  */
  82 /* Read, write, and execute by others.  */
  83 # define S_IRWXO        (S_IRWXG >> 3)
  84 #endif
  85
  86 #ifdef  __USE_MISC
  87 # ifndef R_OK                   /* Verbatim from <unistd.h>.  Ugh.  */
  88 /* Values for the second argument to access.
  89    These may be OR'd together.  */
  90 #  define R_OK  4               /* Test for read permission.  */
  91 #  define W_OK  2               /* Test for write permission.  */
  92 #  define X_OK  1               /* Test for execute permission.  */
  93 #  define F_OK  0               /* Test for existence.  */
  94 # endif
  95 #endif /* Use misc.  */
  96
  97 /* XPG wants the following symbols.   <stdio.h> has the same definitions.  */
  98 #if defined __USE_XOPEN || defined __USE_XOPEN2K8
  99 # define SEEK_SET       0       /* Seek from beginning of file.  */
 100 # define SEEK_CUR       1       /* Seek from current position.  */
 101 # define SEEK_END       2       /* Seek from end of file.  */
 102 #endif  /* XPG */
 103
 104 #ifdef __USE_ATFILE
 105 # define AT_FDCWD               -100    /* Special value used to indicate
 106                                            the *at functions should use the
 107                                            current working directory. */
 108 # define AT_SYMLINK_NOFOLLOW    0x100   /* Do not follow symbolic links.  */
 109 # define AT_REMOVEDIR           0x200   /* Remove directory instead of
 110                                            unlinking file.  */
 111 # define AT_SYMLINK_FOLLOW      0x400   /* Follow symbolic links.  */
 112 # ifdef __USE_GNU
 113 #  define AT_NO_AUTOMOUNT       0x800   /* Suppress terminal automount
 114                                            traversal.  */
 115 #  define AT_EMPTY_PATH         0x1000  /* Allow empty relative pathname.  */
 116 # endif
 117 # define AT_EACCESS             0x200   /* Test access permitted for
 118                                            effective IDs, not real IDs.  */
 119 #endif
 120
 121 /* Do the file control operation described by CMD on FD.
 122    The remaining arguments are interpreted depending on CMD.
 123
 124    This function is a cancellation point and therefore not marked with
 125    __THROW.  */
 126 extern int fcntl (int __fd, int __cmd, ...);
 127
 128 /* Open FILE and return a new file descriptor for it, or -1 on error.
 129    OFLAG determines the type of access used.  If O_CREAT is on OFLAG,
 130    the third argument is taken as a `mode_t', the mode of the created file.
 131
 132    This function is a cancellation point and therefore not marked with
 133    __THROW.  */
 134 #ifndef __USE_FILE_OFFSET64
 135 extern int open (const char *__file, int __oflag, ...) __nonnull ((1));
 136 #else
 137 # ifdef __REDIRECT
 138 extern int __REDIRECT (open, (const char *__file, int __oflag, ...), open64)
 139      __nonnull ((1));
 140 # else
 141 #  define open open64
 142 # endif
 143 #endif
 144 #ifdef __USE_LARGEFILE64
 145 extern int open64 (const char *__file, int __oflag, ...) __nonnull ((1));
 146 #endif
 147
 148 #ifdef __USE_ATFILE
 149 /* Similar to `open' but a relative path name is interpreted relative to
 150    the directory for which FD is a descriptor.
 151
 152    NOTE: some other `openat' implementation support additional functionality
 153    through this interface, especially using the O_XATTR flag.  This is not
 154    yet supported here.
 155
 156    This function is a cancellation point and therefore not marked with
 157    __THROW.  */
 158 # ifndef __USE_FILE_OFFSET64
 159 extern int openat (int __fd, const char *__file, int __oflag, ...)
 160      __nonnull ((2));
 161 # else
 162 #  ifdef __REDIRECT
 163 extern int __REDIRECT (openat, (int __fd, const char *__file, int __oflag,
 164                                 ...), openat64) __nonnull ((2));
 165 #  else
 166 #   define openat openat64
 167 #  endif
 168 # endif
 169 # ifdef __USE_LARGEFILE64
 170 extern int openat64 (int __fd, const char *__file, int __oflag, ...)
 171      __nonnull ((2));
 172 # endif
 173 #endif
 174
 175 /* Create and open FILE, with mode MODE.  This takes an `int' MODE
 176    argument because that is what `mode_t' will be widened to.
 177
 178    This function is a cancellation point and therefore not marked with
 179    __THROW.  */
 180 #ifndef __USE_FILE_OFFSET64
 181 extern int creat (const char *__file, __mode_t __mode) __nonnull ((1));
 182 #else
 183 # ifdef __REDIRECT
 184 extern int __REDIRECT (creat, (const char *__file, __mode_t __mode),
 185                        creat64) __nonnull ((1));
 186 # else
 187 #  define creat creat64
 188 # endif
 189 #endif
 190 #ifdef __USE_LARGEFILE64
 191 extern int creat64 (const char *__file, __mode_t __mode) __nonnull ((1));
 192 #endif
 193
 194 #if !defined F_LOCK && (defined __USE_MISC || (defined __USE_XOPEN_EXTENDED \
 195                                                && !defined __USE_POSIX))
 196 /* NOTE: These declarations also appear in <unistd.h>; be sure to keep both
 197    files consistent.  Some systems have them there and some here, and some
 198    software depends on the macros being defined without including both.  */
 199
 200 /* `lockf' is a simpler interface to the locking facilities of `fcntl'.
 201    LEN is always relative to the current file position.
 202    The CMD argument is one of the following.  */
 203
 204 # define F_ULOCK 0      /* Unlock a previously locked region.  */
 205 # define F_LOCK  1      /* Lock a region for exclusive use.  */
 206 # define F_TLOCK 2      /* Test and lock a region for exclusive use.  */
 207 # define F_TEST  3      /* Test a region for other processes locks.  */
 208
 209 # ifndef __USE_FILE_OFFSET64
 210 extern int lockf (int __fd, int __cmd, __off_t __len);
 211 # else
 212 #  ifdef __REDIRECT
 213 extern int __REDIRECT (lockf, (int __fd, int __cmd, __off64_t __len), lockf64);
 214 #  else
 215 #   define lockf lockf64
 216 #  endif
 217 # endif
 218 # ifdef __USE_LARGEFILE64
 219 extern int lockf64 (int __fd, int __cmd, __off64_t __len);
 220 # endif
 221 #endif
 222
 223 #ifdef __USE_XOPEN2K
 224 /* Advice the system about the expected behaviour of the application with
 225    respect to the file associated with FD.  */
 226 # ifndef __USE_FILE_OFFSET64
 227 extern int posix_fadvise (int __fd, __off_t __offset, __off_t __len,
 228                           int __advise) __THROW;
 229 # else
 230  # ifdef __REDIRECT_NTH
 231 extern int __REDIRECT_NTH (posix_fadvise, (int __fd, __off64_t __offset,
 232                                            __off64_t __len, int __advise),
 233                            posix_fadvise64);
 234 #  else
 235 #   define posix_fadvise posix_fadvise64
 236 #  endif
 237 # endif
 238 # ifdef __USE_LARGEFILE64
 239 extern int posix_fadvise64 (int __fd, __off64_t __offset, __off64_t __len,
 240                             int __advise) __THROW;
 241 # endif
 242
 243
 244 /* Reserve storage for the data of the file associated with FD.
 245
 246    This function is a possible cancellation point and therefore not
 247    marked with __THROW.  */
 248 # ifndef __USE_FILE_OFFSET64
 249 extern int posix_fallocate (int __fd, __off_t __offset, __off_t __len);
 250 # else
 251  # ifdef __REDIRECT
 252 extern int __REDIRECT (posix_fallocate, (int __fd, __off64_t __offset,
 253                                          __off64_t __len),
 254                        posix_fallocate64);
 255 #  else
 256 #   define posix_fallocate posix_fallocate64
 257 #  endif
 258 # endif
 259 # ifdef __USE_LARGEFILE64
 260 extern int posix_fallocate64 (int __fd, __off64_t __offset, __off64_t __len);
 261 # endif
 262 #endif
 263
 264
 265 /* Define some inlines helping to catch common problems.  */
 266 #if __USE_FORTIFY_LEVEL > 0 && defined __fortify_function \
 267     && defined __va_arg_pack_len
 268 # include <bits/fcntl2.h>
 269 #endif
 270
 271 __END_DECLS
 272
 273 #endif /* fcntl.h  */