lock.c revision dab68864983c4a0c6ef9e6d7e5834472c4c75f9c 
1/*
2 * $Id: lock.c,v 1.1 2004/11/14 07:26:26 paulus Exp $
3 *
4 * Copyright (C) 1997 Lars Fenneberg
5 *
6 * See the file COPYRIGHT for the respective terms and conditions.
7 * If the file is missing contact me at lf@elemental.net
8 * and I'll send you a copy.
9 *
10 */
11
12#include "includes.h"
13#include <unistd.h>
14#include <fcntl.h>
15
16int do_lock_exclusive(int fd)
17{
18	struct flock fl;
19	int res;
20
21	memset((void *)&fl, 0, sizeof(fl));
22
23	fl.l_type = F_WRLCK;
24	fl.l_whence = fl.l_start = 0;
25	fl.l_len = 0; /* 0 means "to end of file" */
26
27	res = fcntl(fd, F_SETLK, &fl);
28
29	if ((res == -1) && (errno == EAGAIN))
30		errno = EWOULDBLOCK;
31
32	return res;
33}
34
35int do_unlock(int fd)
36{
37	struct flock fl;
38
39	memset((void *)&fl, 0, sizeof(fl));
40
41	fl.l_type = F_UNLCK;
42	fl.l_whence = fl.l_start = 0;
43	fl.l_len = 0; /* 0 means "to end of file" */
44
45	return fcntl(fd, F_SETLK, &fl);
46}
47