/*
* Copyright (C) 2021 P. J. McDermott
*
* This file is part of @
*
* @ 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 3 of the License, or
* (at your option) any later version.
*
* @ 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 @. If not, see .
*/
#define _XOPEN_SOURCE
#include
#include
#include
#include
#include "datetime.h"
static const char *DATETIME_FMTS_[] = {
#include "datetime-formats.c"
NULL
};
int
datetime_parse(const char *input, time_t *arg_sec)
{
int i;
char *end;
struct tm arg_tm;
time_t now_sec;
struct tm *now_tm;
for (i = 0; DATETIME_FMTS_[i] != NULL; ++i) {
arg_tm.tm_year = INT_MIN; /* Sentinel */
arg_tm.tm_mday = INT_MIN; /* Sentinel */
arg_tm.tm_sec = 0; /* Default */
arg_tm.tm_isdst = -1;
end = strptime(input, DATETIME_FMTS_[i], &arg_tm);
if (end != NULL && *end == '\0') {
goto found;
}
}
fprintf(stderr, "Unknown date format\n");
return -1;
found:
/* TODO: Support %a-only dates */
if (arg_tm.tm_mday == INT_MIN) {
/* No date specified; try today. */
now_sec = time(NULL);
now_tm = localtime(&now_sec);
arg_tm.tm_year = now_tm->tm_year;
arg_tm.tm_mon = now_tm->tm_mon;
arg_tm.tm_mday = now_tm->tm_mday;
*arg_sec = mktime(&arg_tm);
if (*arg_sec <= mktime(now_tm)) {
/* Specified time already happened today; use tomorrow.
* Adding the number of seconds in a day is a shortcut
* that ignores leap seconds. One better method would
* be to increment tm_mday % days in tm_mon, etc. */
*arg_sec += 60 * 60 * 24;
now_tm = localtime(arg_sec);
arg_tm.tm_year = now_tm->tm_year;
arg_tm.tm_mon = now_tm->tm_mon;
arg_tm.tm_mday = now_tm->tm_mday;
*arg_sec = mktime(&arg_tm);
}
} else if (arg_tm.tm_year == INT_MIN) {
/* No year specified; try this year. */
now_sec = time(NULL);
now_tm = localtime(&now_sec);
arg_tm.tm_year = now_tm->tm_year;
*arg_sec = mktime(&arg_tm);
if (*arg_sec <= mktime(now_tm)) {
/* Specified time already happened this year; use next
* year. */
++arg_tm.tm_year;
*arg_sec = mktime(&arg_tm);
}
} else {
*arg_sec = mktime(&arg_tm);
}
return 0;
}