misc/sys/file.h

   1 /* Copyright (C) 1991-2023 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    <https://www.gnu.org/licenses/>.  */
  17
  18 #ifndef _SYS_FILE_H
  19 #define _SYS_FILE_H     1
  20
  21 #include <features.h>
  22
  23 #ifndef _FCNTL_H
  24 # include <fcntl.h>
  25 #endif
  26
  27 __BEGIN_DECLS
  28
  29
  30 /* Alternate names for values for the WHENCE argument to `lseek'.
  31    These are the same as SEEK_SET, SEEK_CUR, and SEEK_END, respectively.  */
  32 #ifndef L_SET
  33 # define L_SET  0       /* Seek from beginning of file.  */
  34 # define L_INCR 1       /* Seek from current position.  */
  35 # define L_XTND 2       /* Seek from end of file.  */
  36 #endif
  37
  38
  39 /* Operations for the `flock' call.  */
  40 #define LOCK_SH 1       /* Shared lock.  */
  41 #define LOCK_EX 2       /* Exclusive lock.  */
  42 #define LOCK_UN 8       /* Unlock.  */
  43
  44 /* Can be OR'd in to one of the above.  */
  45 #define LOCK_NB 4       /* Don't block when locking.  */
  46
  47
  48 /* Apply or remove an advisory lock, according to OPERATION,
  49    on the file FD refers to.  */
  50 extern int flock (int __fd, int __operation) __THROW;
  51
  52
  53 __END_DECLS
  54
  55 #endif /* sys/file.h  */