1 /* Copyright (C) 1994, 1996, 1997, 1998, 2000 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
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.
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.
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 not,
16 see <http://www.gnu.org/licenses/>. */
20 #include <sys/types.h>
25 #include <sys/syscall.h>
31 #define F_GETLK F_GETLK64
33 #define F_SETLK F_SETLK64
38 /* lockf is a simplified interface to fcntl's locking facilities. */
40 int lockf64 (int fd, int cmd, off64_t len64)
43 off_t len = (off_t) len64;
45 if (len64 != (off64_t) len)
47 /* We can't represent the length. */
48 __set_errno(EOVERFLOW);
52 memset((char *) &fl, '\0', sizeof (fl));
54 /* lockf is always relative to the current file position. */
55 fl.l_whence = SEEK_CUR;
62 /* Test the lock: return 0 if FD is unlocked or locked by this process;
63 return -1, set errno to EACCES, if another process holds the lock. */
65 if (fcntl (fd, F_GETLK, &fl) < 0)
67 if (fl.l_type == F_UNLCK || fl.l_pid == getpid ())
90 return fcntl(fd, cmd, &fl);