localtime.c

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/*
 * localtime - convert a calendar time into broken down time
 */
/* $Header: /opt/proj/minix/cvsroot/src/lib/ansi/localtime.c,v 1.1.1.1 2005/04/21 14:56:05 beng Exp $ */

#include        <time.h>
#include        "loc_time.h"

/* We must be careful, since an int can't represent all the seconds in a day.
 * Hence the adjustment of minutes when adding timezone and dst information.
 * This assumes that both must be expressable in multiples of a minute.
 * Furthermore, it is assumed that both fit into an integer when expressed as
 * minutes (this is about 22 days, so this should not cause any problems). 
 */
struct tm *
localtime(const time_t *timer)
{
        struct tm *timep;
        unsigned dst;

        _tzset();
        timep = gmtime(timer);                  /* tm->tm_isdst == 0 */
        timep->tm_min -= _timezone / 60;
        timep->tm_sec -= _timezone % 60;
        mktime(timep);

        dst = _dstget(timep);
        if (dst) {
                timep->tm_min += dst / 60;
                timep->tm_sec += dst % 60;
                mktime(timep);
        }
        return timep;
}

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