xref: /dragonfly/lib/libc/gen/getosreldate.c (revision 1975d09e)
1 /*
2  * Copyright (c) 1989, 1993, 2020
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * @(#)gethostid.c	8.1 (Berkeley) 6/2/93
30  * $FreeBSD: src/lib/libc/gen/getosreldate.c,v 1.4 1999/08/27 23:58:43 peter Exp $
31  */
32 
33 #include <sys/param.h>
34 #include <sys/sysctl.h>
35 
36 #include <unistd.h>
37 
38 static int save_osreldate;
39 
40 int
41 getosreldate(void)
42 {
43 	int mib[2];
44 	size_t size;
45 	int value;
46 
47 	if (save_osreldate)
48 		return save_osreldate;
49 
50 	mib[0] = CTL_KERN;
51 	mib[1] = KERN_OSRELDATE;
52 	size = sizeof value;
53 	if (sysctl(mib, 2, &value, &size, NULL, 0) == -1)
54 		return (-1);
55 	save_osreldate = value;
56 
57 	return (value);
58 }
59