misc/sys/file.h

   1 /* Copyright (C) 1991, 1992 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, 1992 Free Software Foundation, Inc., 675 Mass Ave,
  17 Cambridge, MA 02139, USA.  */
  18
  19 #ifndef _SYS_FILE_H
  20
  21 #define _SYS_FILE_H     1
  22 #include <features.h>
  23
  24 #ifndef _FCNTL_H
  25 #include <fcntl.h>
  26 #endif
  27
  28 __BEGIN_DECLS
  29
  30
  31 /* Alternate names for values for the WHENCE argument to `lseek'.
  32    These are the same as SEEK_SET, SEEK_CUR, and SEEK_END, respectively.  */
  33 #ifndef L_SET
  34 #define L_SET   0       /* Seek from beginning of file.  */
  35 #define L_INCR  1       /* Seek from current position.  */
  36 #define L_XTND  2       /* Seek from end of file.  */
  37 #endif
  38
  39
  40 /* Operations for the `flock' call.  */
  41 #define LOCK_SH 1    /* Shared lock.  */
  42 #define LOCK_EX 2    /* Exclusive lock.  */
  43 #define LOCK_UN 8    /* Unlock.  */
  44
  45 /* Can be OR'd in to one of the above.  */
  46 #define LOCK_NB 4    /* Don't block when locking.  */
  47
  48
  49 /* Apply or remove an advisory lock, according to OPERATION,
  50    on the file FD refers to.  */
  51 extern int __flock __P ((int __fd, int __operation));
  52 extern int flock __P ((int __fd, int __operation));
  53
  54
  55 __END_DECLS
  56
  57 #endif /* sys/file.h  */