io/fcntl.h

   1 /* Copyright (C) 1991, 92, 94, 95, 96 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 Library General Public License as
   6 published by the Free Software Foundation; either version 2 of the
   7 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 Library General Public License for more details.
  13
  14 You should have received a copy of the GNU Library General Public
  15 License along with the GNU C Library; see the file COPYING.LIB.  If
  16 not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, USA.  */
  18
  19 /*
  20  *      POSIX Standard: 6.5 File Control Operations     <fcntl.h>
  21  */
  22
  23 #ifndef _FCNTL_H
  24
  25 #define _FCNTL_H        1
  26 #include <features.h>
  27
  28 /* This must be early so <fcntlbits.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 <fcntlbits.h>
  34
  35 #ifdef  __USE_MISC
  36 #ifndef R_OK                    /* Verbatim from <unistd.h>.  Ugh.  */
  37 /* Values for the second argument to access.
  38    These may be OR'd together.  */
  39 #define R_OK    4               /* Test for read permission.  */
  40 #define W_OK    2               /* Test for write permission.  */
  41 #define X_OK    1               /* Test for execute permission.  */
  42 #define F_OK    0               /* Test for existence.  */
  43 #endif
  44 #endif /* Use misc.  */
  45
  46 /* Do the file control operation described by CMD on FD.
  47    The remaining arguments are interpreted depending on CMD.  */
  48 extern int __fcntl __P ((int __fd, int __cmd, ...));
  49 extern int fcntl __P ((int __fd, int __cmd, ...));
  50
  51 /* Open FILE and return a new file descriptor for it, or -1 on error.
  52    OFLAG determines the type of access used.  If O_CREAT is on OFLAG,
  53    the third argument is taken as a `mode_t', the mode of the created file.  */
  54 extern int __open __P ((__const char *__file, int __oflag, ...));
  55 extern int open __P ((__const char *__file, int __oflag, ...));
  56
  57 /* Create and open FILE, with mode MODE.
  58    This takes an `int' MODE argument because that is
  59    what `mode_t' will be widened to.  */
  60 extern int creat __P ((__const char *__file, __mode_t __mode));
  61
  62 #if defined (__USE_MISC) && !defined (F_LOCK)
  63 /* NOTE: These declarations also appear in <unistd.h>; be sure to keep both
  64    files consistent.  Some systems have them there and some here, and some
  65    software depends on the macros being defined without including both.  */
  66
  67 /* `lockf' is a simpler interface to the locking facilities of `fcntl'.
  68    LEN is always relative to the current file position.
  69    The CMD argument is one of the following.  */
  70
  71 #define F_ULOCK 0       /* Unlock a previously locked region.  */
  72 #define F_LOCK  1       /* Lock a region for exclusive use.  */
  73 #define F_TLOCK 2       /* Test and lock a region for exclusive use.  */
  74 #define F_TEST  3       /* Test a region for other processes locks.  */
  75
  76 extern int lockf __P ((int __fd, int __cmd, __off_t __len));
  77 #endif
  78
  79 __END_DECLS
  80
  81 #endif /* fcntl.h  */