1 /* settime -- set the system clock 2 3 Copyright (C) 2002, 2004-2007, 2009-2021 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 <https://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 31 int 32 settime (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 }