libcasio/lib/date/decode.c

48 lines
1.7 KiB
C

/* ****************************************************************************
* date/decode.c -- decode a date.
* Copyright (C) 2017 Thomas "Cakeisalie5" Touhey <thomas@touhey.fr>
*
* This file is part of libcasio.
* libcasio is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation; either version 3.0 of the License,
* or (at your option) any later version.
*
* libcasio 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 Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with libcasio; if not, see <http://www.gnu.org/licenses/>.
* ************************************************************************* */
#include "../internals.h"
#include <ctype.h>
/**
* casio_decode_date:
* Decode a date from a string.
*
* @arg c the raw string.
* @arg t the destination timestamp.
* @return the error code (0 if ok).
*/
int CASIO_EXPORT casio_decode_date(time_t *t, const char *c)
{
const int two = '0' + '0' * 10, four = two + '0' * 100 + '0' * 1000;
struct tm date;
/* get the tm structure */
memset(&date, 0, sizeof(date));
date.tm_year = c[0] * 1000 + c[1] * 100 + c[2] * 10 + c[3] - four - 1900;
date.tm_mon = c[5] * 10 + c[6] - two - 1;
date.tm_mday = c[7] * 10 + c[8] - two;
date.tm_hour = c[10] * 10 + c[11] - two;
date.tm_min = c[12] * 10 + c[13] - two;
/* set the timestamp, return */
*t = mktime(&date);
return (0);
}