/*      $NetBSD: stime.c,v 1.7 2008/07/21 14:19:21 lukem Exp $  */

/*
* Copyright (c) 1993
*      The Regents of the University of California.  All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
*    may be used to endorse or promote products derived from this software
*    without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/

#include <sys/cdefs.h>
#ifndef lint
__COPYRIGHT("@(#) Copyright (c) 1993\
The Regents of the University of California.  All rights reserved.");
#endif /* not lint */

#ifndef lint
#if 0
static char sccsid[] = "from: @(#)touch.c       8.2 (Berkeley) 4/28/95";
#endif
__RCSID("$NetBSD: stime.c,v 1.7 2008/07/21 14:19:21 lukem Exp $");
#endif /* not lint */

#include <err.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <tzfile.h>

#include "stime.h"

#define ATOI2(s)        ((s) += 2, ((s)[-2] - '0') * 10 + ((s)[-1] - '0'))

time_t
stime(char *arg)
{
       struct tm *t;
       time_t tmptime;
       int yearset;
       char *p;
                                       /* Start with the current time. */
       if (time(&tmptime) == (time_t)-1)
               err(EXIT_FAILURE, "time");

       if ((t = localtime(&tmptime)) == NULL)
               err(EXIT_FAILURE, "localtime");
                                       /* [[CC]YY]MMDDhhmm[.SS] */
       if ((p = strchr(arg, '.')) == NULL)
               t->tm_sec = 0;          /* Seconds defaults to 0. */
       else {
               if (strlen(p + 1) != 2)
                       goto terr;
               *p++ = '\0';
               t->tm_sec = ATOI2(p);
       }

       yearset = 0;
       switch (strlen(arg)) {
       case 12:                        /* CCYYMMDDhhmm */
               t->tm_year = ATOI2(arg) * 100 - TM_YEAR_BASE;
               yearset = 1;
               /* FALLTHROUGH */
       case 10:                        /* YYMMDDhhmm */
               if (yearset) {
                       t->tm_year += ATOI2(arg);
               } else {
                       yearset = ATOI2(arg);
                       t->tm_year = conv_2dig_year(yearset) - TM_YEAR_BASE;
               }
               /* FALLTHROUGH */
       case 8:                         /* MMDDhhmm */
               t->tm_mon = ATOI2(arg);
               --t->tm_mon;            /* Convert from 01-12 to 00-11 */
               /* FALLTHROUGH */
       case 6:
               t->tm_mday = ATOI2(arg);
               /* FALLTHROUGH */
       case 4:
               t->tm_hour = ATOI2(arg);
               /* FALLTHROUGH */
       case 2:
               t->tm_min = ATOI2(arg);
               break;
       default:
               goto terr;
       }

       t->tm_isdst = -1;               /* Figure out DST. */
       tmptime = mktime(t);
       if (tmptime == (time_t)-1) {
terr:          errx(EXIT_FAILURE,
    "out of range or illegal time specification: [[CC]YY]MMDDhhmm[.SS]");
       }
       return tmptime;
}