1/* settime -- set the system clock
2
3   Copyright (C) 2002, 2004-2007, 2009-2010 Free Software Foundation, Inc.
4
5   This program is free software: you can redistribute it and/or modify
6   it under the terms of the GNU General Public License as published by
7   the Free Software Foundation; either version 3 of the License, or
8   (at your option) any later version.
9
10   This program is distributed in the hope that it will be useful,
11   but WITHOUT ANY WARRANTY; without even the implied warranty of
12   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13   GNU General Public License for more details.
14
15   You should have received a copy of the GNU General Public License
16   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
17
18/* Written by Paul Eggert.  */
19
20#include <config.h>
21
22#include "timespec.h"
23
24#include <sys/time.h>
25#include <unistd.h>
26
27#include <errno.h>
28
29/* Set the system time.  */
30
31int
32settime (struct timespec const *ts)
33{
34#if defined CLOCK_REALTIME && HAVE_CLOCK_SETTIME
35  {
36    int r = clock_settime (CLOCK_REALTIME, ts);
37    if (r == 0 || errno == EPERM)
38      return r;
39  }
40#endif
41
42#if HAVE_SETTIMEOFDAY
43  {
44    struct timeval tv;
45
46    tv.tv_sec = ts->tv_sec;
47    tv.tv_usec = ts->tv_nsec / 1000;
48    return settimeofday (&tv, 0);
49  }
50#elif HAVE_STIME
51  /* This fails to compile on OSF1 V5.1, due to stime requiring
52     a `long int*' and tv_sec is `int'.  But that system does provide
53     settimeofday.  */
54  return stime (&ts->tv_sec);
55#else
56  errno = ENOSYS;
57  return -1;
58#endif
59}
60