io/fcntl.h

   1 /* Copyright (C) 1991,1992,1994-2001,2003,2004,2005
   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, write to the Free
  17    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  18    02111-1307 USA.  */
  19
  20 /*
  21  *      POSIX Standard: 6.5 File Control Operations     <fcntl.h>
  22  */
  23
  24 #ifndef _FCNTL_H
  25 #define _FCNTL_H        1
  26
  27 #include <features.h>
  28
  29 /* This must be early so <bits/fcntl.h> can define types winningly.  */
  30 __BEGIN_DECLS
  31
  32 /* Get the definitions of O_*, F_*, FD_*: all the
  33    numbers and flag bits for `open', `fcntl', et al.  */
  34 #include <bits/fcntl.h>
  35
  36 /* For XPG all symbols from <sys/stat.h> should also be available.  */
  37 #ifdef __USE_XOPEN
  38 # include <sys/stat.h>
  39 #endif
  40
  41 #ifdef  __USE_MISC
  42 # ifndef R_OK                   /* Verbatim from <unistd.h>.  Ugh.  */
  43 /* Values for the second argument to access.
  44    These may be OR'd together.  */
  45 #  define R_OK  4               /* Test for read permission.  */
  46 #  define W_OK  2               /* Test for write permission.  */
  47 #  define X_OK  1               /* Test for execute permission.  */
  48 #  define F_OK  0               /* Test for existence.  */
  49 # endif
  50 #endif /* Use misc.  */
  51
  52 /* XPG wants the following symbols.  */
  53 #ifdef __USE_XOPEN              /* <stdio.h> has the same definitions.  */
  54 # define SEEK_SET       0       /* Seek from beginning of file.  */
  55 # define SEEK_CUR       1       /* Seek from current position.  */
  56 # define SEEK_END       2       /* Seek from end of file.  */
  57 #endif  /* XPG */
  58
  59 #ifdef __USE_GNU
  60 # define AT_FDCWD               -100    /* Special value used to indicate
  61                                            openat should use the current
  62                                            working directory. */
  63 # define AT_SYMLINK_NOFOLLOW    0x100   /* Do not follow symbolic links.  */
  64 # define AT_REMOVEDIR           0x200   /* Remove directory instead of
  65                                            unlinking file.  */
  66 #endif
  67
  68 /* Do the file control operation described by CMD on FD.
  69    The remaining arguments are interpreted depending on CMD.
  70
  71    This function is a cancellation point and therefore not marked with
  72    __THROW.  */
  73 extern int fcntl (int __fd, int __cmd, ...);
  74
  75 /* Open FILE and return a new file descriptor for it, or -1 on error.
  76    OFLAG determines the type of access used.  If O_CREAT is on OFLAG,
  77    the third argument is taken as a `mode_t', the mode of the created file.
  78
  79    This function is a cancellation point and therefore not marked with
  80    __THROW.  */
  81 #ifndef __USE_FILE_OFFSET64
  82 extern int open (__const char *__file, int __oflag, ...) __nonnull ((1));
  83 #else
  84 # ifdef __REDIRECT
  85 extern int __REDIRECT (open, (__const char *__file, int __oflag, ...), open64)
  86      __nonnull ((1));
  87 # else
  88 #  define open open64
  89 # endif
  90 #endif
  91 #ifdef __USE_LARGEFILE64
  92 extern int open64 (__const char *__file, int __oflag, ...) __nonnull ((1));
  93 #endif
  94
  95 #ifdef __USE_GNU
  96 /* Similar to OPEN but a relative path name is interpreted relative to
  97    the directory for which FD is a descriptor.
  98
  99    NOTE: some other OPENAT implementation support additional functionality
 100    through this interface, especially using the O_XATTR flag.  This is not
 101    yet supported here.
 102
 103    This function is a cancellation point and therefore not marked with
 104    __THROW.  */
 105 # ifndef __USE_FILE_OFFSET64
 106 extern int openat (int __fd, __const char *__file, int __oflag, ...)
 107      __nonnull ((2));
 108 # else
 109 #  ifdef __REDIRECT
 110 extern int __REDIRECT (openat, (int __fd, __const char *__file, int __oflag,
 111                                 ...), openat64) __nonnull ((2));
 112 #  else
 113 #   define openat openat64
 114 #  endif
 115 # endif
 116
 117 # ifdef __USE_LARGEFILE64
 118 extern int openat64 (int __fd, __const char *__file, int __oflag, ...)
 119      __nonnull ((2));
 120 # endif
 121 #endif
 122
 123 /* Create and open FILE, with mode MODE.  This takes an `int' MODE
 124    argument because that is what `mode_t' will be widened to.
 125
 126    This function is a cancellation point and therefore not marked with
 127    __THROW.  */
 128 #ifndef __USE_FILE_OFFSET64
 129 extern int creat (__const char *__file, __mode_t __mode) __nonnull ((1));
 130 #else
 131 # ifdef __REDIRECT
 132 extern int __REDIRECT (creat, (__const char *__file, __mode_t __mode),
 133                        creat64) __nonnull ((1));
 134 # else
 135 #  define creat creat64
 136 # endif
 137 #endif
 138 #ifdef __USE_LARGEFILE64
 139 extern int creat64 (__const char *__file, __mode_t __mode) __nonnull ((1));
 140 #endif
 141
 142 #if !defined F_LOCK && (defined __USE_MISC || (defined __USE_XOPEN_EXTENDED \
 143                                                && !defined __USE_POSIX))
 144 /* NOTE: These declarations also appear in <unistd.h>; be sure to keep both
 145    files consistent.  Some systems have them there and some here, and some
 146    software depends on the macros being defined without including both.  */
 147
 148 /* `lockf' is a simpler interface to the locking facilities of `fcntl'.
 149    LEN is always relative to the current file position.
 150    The CMD argument is one of the following.  */
 151
 152 # define F_ULOCK 0      /* Unlock a previously locked region.  */
 153 # define F_LOCK  1      /* Lock a region for exclusive use.  */
 154 # define F_TLOCK 2      /* Test and lock a region for exclusive use.  */
 155 # define F_TEST  3      /* Test a region for other processes locks.  */
 156
 157 # ifndef __USE_FILE_OFFSET64
 158 extern int lockf (int __fd, int __cmd, __off_t __len);
 159 # else
 160 # ifdef __REDIRECT
 161 extern int __REDIRECT (lockf, (int __fd, int __cmd, __off64_t __len), lockf64);
 162 # else
 163 #  define lockf lockf64
 164 # endif
 165 # endif
 166 # ifdef __USE_LARGEFILE64
 167 extern int lockf64 (int __fd, int __cmd, __off64_t __len);
 168 # endif
 169 #endif
 170
 171 #ifdef __USE_XOPEN2K
 172 /* Advice the system about the expected behaviour of the application with
 173    respect to the file associated with FD.  */
 174 # ifndef __USE_FILE_OFFSET64
 175 extern int posix_fadvise (int __fd, __off_t __offset, __off_t __len,
 176                           int __advise) __THROW;
 177 # else
 178 # ifdef __REDIRECT_NTH
 179 extern int __REDIRECT_NTH (posix_fadvise, (int __fd, __off64_t __offset,
 180                                            __off64_t __len, int __advise),
 181                            posix_fadvise64);
 182 # else
 183 #  define posix_fadvise posix_fadvise64
 184 # endif
 185 # endif
 186 # ifdef __USE_LARGEFILE64
 187 extern int posix_fadvise64 (int __fd, __off64_t __offset, __off64_t __len,
 188                             int __advise) __THROW;
 189 # endif
 190
 191
 192 /* Reserve storage for the data of the file associated with FD.
 193
 194    This function is a possible cancellation points and therefore not
 195    marked with __THROW.  */
 196 # ifndef __USE_FILE_OFFSET64
 197 extern int posix_fallocate (int __fd, __off_t __offset, __off_t __len);
 198 # else
 199 # ifdef __REDIRECT
 200 extern int __REDIRECT (posix_fallocate, (int __fd, __off64_t __offset,
 201                                          __off64_t __len),
 202                        posix_fallocate64);
 203 # else
 204 #  define posix_fallocate posix_fallocate64
 205 # endif
 206 # endif
 207 # ifdef __USE_LARGEFILE64
 208 extern int posix_fallocate64 (int __fd, __off64_t __offset, __off64_t __len);
 209 # endif
 210 #endif
 211
 212 __END_DECLS
 213
 214 #endif /* fcntl.h  */