gettimeofday.c   [plain text]


/*
 * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * The contents of this file constitute Original Code as defined in and
 * are subject to the Apple Public Source License Version 1.1 (the
 * "License").  You may not use this file except in compliance with the
 * License.  Please obtain a copy of the License at
 * http://www.apple.com/publicsource and read it before using this file.
 * 
 * This Original Code and all software distributed under the License are
 * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
 * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
 * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
 * License for the specific language governing rights and limitations
 * under the License.
 * 
 * @APPLE_LICENSE_HEADER_END@
 */
/*
 * Copyright (c) 1995 NeXT Computer, Inc. All Rights Reserved
 *
 * 	File:	libc/sys/gettimeofday.c
 */

#include <time.h>
#include <tzfile.h>
#include <sys/time.h>
#include <errno.h>
#include <sys/syscall.h>
#include <unistd.h>

int gettimeofday (struct timeval *tp, struct timezone *tzp)
{
        static int validtz = 0;
        static struct timezone cached_tz = {0};

        if (syscall (SYS_gettimeofday, tp, tzp) < 0) {
                return (-1);
        }
        if (validtz == 0)  {
		struct tm *localtm = localtime ((time_t *)&tp->tv_sec);
                cached_tz.tz_dsttime = localtm->tm_isdst;
                cached_tz.tz_minuteswest =
                        (-localtm->tm_gmtoff / SECSPERMIN) +
                        (localtm->tm_isdst * MINSPERHOUR);
                validtz = 1;
        }
        if (tzp) {
          tzp->tz_dsttime = cached_tz.tz_dsttime;
          tzp->tz_minuteswest = cached_tz.tz_minuteswest;
        }
        return (0);
}