Subversion Repositories scarts

/* dostime.c - convert dos time to/from time_t.

   Copyright (C) 2002 Free Software Foundation

  This program is free software; you can redistribute it and/or

  modify it under the terms of the GNU General Public License

  as published by the Free Software Foundation; either version 2

  of the License, or (at your option) any later version.

  This program is distributed in the hope that it will be useful,

  but WITHOUT ANY WARRANTY; without even the implied warranty of

  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License

  along with this program; if not, write to the Free Software

  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

*/

#include <config.h>

#include <time.h>

#include <stddef.h>

#include "dostime.h"

/*

 * The specification to which this was written.  From Joe Buck.

 * The DOS format appears to have only 2 second resolution.  It is an

 * unsigned long, and ORs together

 *

 * (year-1980)<<25

 * month<<21  (month is tm_mon + 1, 1=Jan through 12=Dec)

 * day<<16    (day is tm_mday, 1-31)

 * hour<<11   (hour is tm_hour, 0-23)

 * min<<5          (min is tm_min, 0-59)

 * sec>>1          (sec is tm_sec, 0-59, that's right, we throw away the LSB)

 *

 * DOS uses local time, so the localtime() call is used to turn the time_t

 * into a struct tm.

 */

time_t

dos2unixtime (unsigned long dostime)

{

  struct tm ltime;

  time_t now = time (NULL);

  /* Call localtime to initialize timezone in TIME.  */

  ltime = *localtime (&now);

  ltime.tm_year = (dostime >> 25) + 80;

  ltime.tm_mon = ((dostime >> 21) & 0x0f) - 1;

  ltime.tm_mday = (dostime >> 16) & 0x1f;

  ltime.tm_hour = (dostime >> 11) & 0x0f;

  ltime.tm_min = (dostime >> 5) & 0x3f;

  ltime.tm_sec = (dostime & 0x1f) << 1;

  ltime.tm_wday = -1;

  ltime.tm_yday = -1;

  ltime.tm_isdst = -1;

  return mktime (&ltime);

}

unsigned long

unix2dostime (time_t *time)

{

  struct tm *ltime = localtime (time);

  int year = ltime->tm_year - 80;

  if (year < 0)

    year = 0;

  return (year << 25

          | (ltime->tm_mon + 1) << 21

          | ltime->tm_mday << 16

          | ltime->tm_hour << 11

          | ltime->tm_min << 5

          | ltime->tm_sec >> 1);

}