xref: /dragonfly/usr.bin/calendar/parsedata.c (revision 0212bfce)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 1992-2009 Edwin Groothuis <edwin@FreeBSD.org>.
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  *
28  * $FreeBSD: head/usr.bin/calendar/parsedata.c 326276 2017-11-27 15:37:16Z pfg $
29  */
30 
31 #include <ctype.h>
32 #include <math.h>
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <string.h>
36 #include <err.h>
37 
38 #include "calendar.h"
39 
40 static char *showflags(int flags);
41 static bool isonlydigits(char *s, int nostar);
42 static const char *getmonthname(int i);
43 static int checkmonth(char *s, size_t *len, size_t *offset, const char **month);
44 static const char *getdayofweekname(int i);
45 static int checkdayofweek(char *s, size_t *len, size_t *offset, const char **dow);
46 static int indextooffset(char *s);
47 static int parseoffset(char *s);
48 static char *floattoday(int year, double f);
49 static char *floattotime(double f);
50 static int wdayom(int day, int offset, int month, int year);
51 static int determinestyle(char *date, int *flags, char *month, int *imonth,
52 	char *dayofmonth, int *idayofmonth, char *dayofweek, int *idayofweek,
53 	char *modifieroffset, char *modifierindex, char *specialday,
54 	char *year, int *iyear);
55 static void remember(int *rememberindex, int *y, int *m, int *d, char **ed,
56 	int yy, int mm, int dd, char *extra);
57 
58 /*
59  * Expected styles:
60  *
61  * Date			::=	Month . ' ' . DayOfMonth |
62  *				Month . ' ' . DayOfWeek . ModifierIndex |
63  *				Month . '/' . DayOfMonth |
64  *				Month . '/' . DayOfWeek . ModifierIndex |
65  *				DayOfMonth . ' ' . Month |
66  *				DayOfMonth . '/' . Month |
67  *				DayOfWeek . ModifierIndex . ' ' .Month |
68  *				DayOfWeek . ModifierIndex . '/' .Month |
69  *				DayOfWeek . ModifierIndex |
70  *				SpecialDay . ModifierOffset
71  *
72  * Month		::=	MonthName | MonthNumber | '*'
73  * MonthNumber		::=	'0' ... '9' | '00' ... '09' | '10' ... '12'
74  * MonthName		::=	MonthNameShort | MonthNameLong
75  * MonthNameLong	::=	'January' ... 'December'
76  * MonthNameShort	::=	'Jan' ... 'Dec' | 'Jan.' ... 'Dec.'
77  *
78  * DayOfWeek		::=	DayOfWeekShort | DayOfWeekLong
79  * DayOfWeekShort	::=	'Mon' .. 'Sun'
80  * DayOfWeekLong	::=	'Monday' .. 'Sunday'
81  * DayOfMonth		::=	'0' ... '9' | '00' ... '09' | '10' ... '29' |
82  *				'30' ... '31' | '*'
83  *
84  * ModifierOffset	::=	'' | '+' . ModifierNumber | '-' . ModifierNumber
85  * ModifierNumber	::=	'0' ... '9' | '00' ... '99' | '000' ... '299' |
86  *				'300' ... '359' | '360' ... '365'
87  * ModifierIndex	::=	'Second' | 'Third' | 'Fourth' | 'Fifth' |
88  *				'First' | 'Last'
89  *
90  * SpecialDay		::=	'Easter' | 'Paskha' | 'ChineseNewYear'
91  *
92  */
93 static int
94 determinestyle(char *date, int *flags,
95     char *month, int *imonth, char *dayofmonth, int *idayofmonth,
96     char *dayofweek, int *idayofweek, char *modifieroffset,
97     char *modifierindex, char *specialday, char *year, int *iyear)
98 {
99 	char *p, *p1, *p2, *py;
100 	const char *dow, *pmonth;
101 	char pold;
102 	size_t len, offset;
103 
104 	*flags = F_NONE;
105 	*month = '\0';
106 	*imonth = 0;
107 	*year = '\0';
108 	*iyear = 0;
109 	*dayofmonth = '\0';
110 	*idayofmonth = 0;
111 	*dayofweek = '\0';
112 	*idayofweek = 0;
113 	*modifieroffset = '\0';
114 	*modifierindex = '\0';
115 	*specialday = '\0';
116 
117 #define CHECKSPECIAL(s1, s2, lens2, type)				\
118 	if (s2 != NULL && strncmp(s1, s2, lens2) == 0) {		\
119 		*flags |= F_SPECIALDAY;					\
120 		*flags |= type;						\
121 		*flags |= F_VARIABLE;					\
122 		if (strlen(s1) == lens2) {				\
123 			strcpy(specialday, s1);				\
124 			return (1);					\
125 		}							\
126 		strncpy(specialday, s1, lens2);				\
127 		specialday[lens2] = '\0';				\
128 		strcpy(modifieroffset, s1 + lens2);			\
129 		*flags |= F_MODIFIEROFFSET;				\
130 		return (1);						\
131 	}
132 
133 	if ((p = strchr(date, ' ')) == NULL) {
134 		if ((p = strchr(date, '/')) == NULL) {
135 			CHECKSPECIAL(date, STRING_CNY, strlen(STRING_CNY),
136 			    F_CNY);
137 			CHECKSPECIAL(date, ncny.name, ncny.len, F_CNY);
138 			CHECKSPECIAL(date, STRING_NEWMOON,
139 			    strlen(STRING_NEWMOON), F_NEWMOON);
140 			CHECKSPECIAL(date, nnewmoon.name, nnewmoon.len,
141 			    F_NEWMOON);
142 			CHECKSPECIAL(date, STRING_FULLMOON,
143 			    strlen(STRING_FULLMOON), F_FULLMOON);
144 			CHECKSPECIAL(date, nfullmoon.name, nfullmoon.len,
145 			    F_FULLMOON);
146 			CHECKSPECIAL(date, STRING_PASKHA,
147 			    strlen(STRING_PASKHA), F_PASKHA);
148 			CHECKSPECIAL(date, npaskha.name, npaskha.len, F_PASKHA);
149 			CHECKSPECIAL(date, STRING_EASTER,
150 			    strlen(STRING_EASTER), F_EASTER);
151 			CHECKSPECIAL(date, neaster.name, neaster.len, F_EASTER);
152 			CHECKSPECIAL(date, STRING_MAREQUINOX,
153 			    strlen(STRING_MAREQUINOX), F_MAREQUINOX);
154 			CHECKSPECIAL(date, nmarequinox.name, nmarequinox.len,
155 			    F_SEPEQUINOX);
156 			CHECKSPECIAL(date, STRING_SEPEQUINOX,
157 			    strlen(STRING_SEPEQUINOX), F_SEPEQUINOX);
158 			CHECKSPECIAL(date, nsepequinox.name, nsepequinox.len,
159 			    F_SEPEQUINOX);
160 			CHECKSPECIAL(date, STRING_JUNSOLSTICE,
161 			    strlen(STRING_JUNSOLSTICE), F_JUNSOLSTICE);
162 			CHECKSPECIAL(date, njunsolstice.name, njunsolstice.len,
163 			    F_JUNSOLSTICE);
164 			CHECKSPECIAL(date, STRING_DECSOLSTICE,
165 			    strlen(STRING_DECSOLSTICE), F_DECSOLSTICE);
166 			CHECKSPECIAL(date, ndecsolstice.name, ndecsolstice.len,
167 			    F_DECSOLSTICE);
168 			if (checkdayofweek(date, &len, &offset, &dow) != 0) {
169 				*flags |= F_DAYOFWEEK;
170 				*flags |= F_VARIABLE;
171 				*idayofweek = offset;
172 				if (strlen(date) == len) {
173 					strcpy(dayofweek, date);
174 					return (1);
175 				}
176 				strncpy(dayofweek, date, len);
177 				dayofweek[len] = '\0';
178 				strcpy(modifierindex, date + len);
179 				*flags |= F_MODIFIERINDEX;
180 				return (1);
181 			}
182 			if (isonlydigits(date, 1)) {
183 				/* Assume month number only */
184 				*flags |= F_MONTH;
185 				*imonth = (int)strtol(date, (char **)NULL, 10);
186 				strcpy(month, getmonthname(*imonth));
187 				return(1);
188 			}
189 			return (0);
190 		}
191 	}
192 
193 	/*
194 	 * After this, leave by goto-ing to "allfine" or "fail" to restore the
195 	 * original data in `date'.
196 	 */
197 	pold = *p;
198 	*p = 0;
199 	p1 = date;
200 	p2 = p + 1;
201 	/* Now p2 points to the next field and p1 to the first field */
202 
203 	if ((py = strchr(p2, '/')) != NULL) {
204 		/* We have a year in the string. Now this is getting tricky */
205 		strcpy(year, p1);
206 		*iyear = (int)strtol(year, NULL, 10);
207 		p1 = p2;
208 		p2 = py + 1;
209 		*py = 0;
210 		*flags |= F_YEAR;
211 	}
212 
213 	/* Check if there is a month-string in the date */
214 	if ((checkmonth(p1, &len, &offset, &pmonth) != 0)
215 	    || (checkmonth(p2, &len, &offset, &pmonth) != 0 && (p2 = p1))) {
216 		/* p2 is the non-month part */
217 		*flags |= F_MONTH;
218 		*imonth = offset;
219 
220 		strcpy(month, getmonthname(offset));
221 		if (isonlydigits(p2, 1)) {
222 			strcpy(dayofmonth, p2);
223 			*idayofmonth = (int)strtol(p2, (char **)NULL, 10);
224 			*flags |= F_DAYOFMONTH;
225 			goto allfine;
226 		}
227 		if (strcmp(p2, "*") == 0) {
228 			*flags |= F_ALLDAY;
229 			goto allfine;
230 		}
231 
232 		if (checkdayofweek(p2, &len, &offset, &dow) != 0) {
233 			*flags |= F_DAYOFWEEK;
234 			*flags |= F_VARIABLE;
235 			*idayofweek = offset;
236 			strcpy(dayofweek, getdayofweekname(offset));
237 			if (strlen(p2) == len)
238 				goto allfine;
239 			strcpy(modifierindex, p2 + len);
240 			*flags |= F_MODIFIERINDEX;
241 			goto allfine;
242 		}
243 		goto fail;
244 	}
245 
246 	/* Check if there is an every-day or every-month in the string */
247 	if ((strcmp(p1, "*") == 0 && isonlydigits(p2, 1))
248 	    || (strcmp(p2, "*") == 0 && isonlydigits(p1, 1) && (p2 = p1))) {
249 		int d;
250 
251 		*flags |= F_ALLMONTH;
252 		*flags |= F_DAYOFMONTH;
253 		d = (int)strtol(p2, (char **)NULL, 10);
254 		*idayofmonth = d;
255 		sprintf(dayofmonth, "%d", d);
256 		goto allfine;
257 	}
258 
259 	/* Month as a number, then a weekday */
260 	if (isonlydigits(p1, 1)
261 	    && checkdayofweek(p2, &len, &offset, &dow) != 0) {
262 		int d;
263 
264 		*flags |= F_MONTH;
265 		*flags |= F_DAYOFWEEK;
266 		*flags |= F_VARIABLE;
267 
268 		*idayofweek = offset;
269 		d = (int)strtol(p1, (char **)NULL, 10);
270 		*imonth = d;
271 		strcpy(month, getmonthname(d));
272 
273 		strcpy(dayofweek, getdayofweekname(offset));
274 		if (strlen(p2) == len)
275 			goto allfine;
276 		strcpy(modifierindex, p2 + len);
277 		*flags |= F_MODIFIERINDEX;
278 		goto allfine;
279 	}
280 
281 	/* If both the month and date are specified as numbers */
282 	if (isonlydigits(p1, 1) && isonlydigits(p2, 0)) {
283 		/* Now who wants to be this ambiguous? :-( */
284 		int m, d;
285 
286 		if (strchr(p2, '*') != NULL)
287 			*flags |= F_VARIABLE;
288 
289 		m = (int)strtol(p1, (char **)NULL, 10);
290 		d = (int)strtol(p2, (char **)NULL, 10);
291 
292 		*flags |= F_MONTH;
293 		*flags |= F_DAYOFMONTH;
294 
295 		if (m > 12) {
296 			*imonth = d;
297 			*idayofmonth = m;
298 			strcpy(month, getmonthname(d));
299 			sprintf(dayofmonth, "%d", m);
300 		} else {
301 			*imonth = m;
302 			*idayofmonth = d;
303 			strcpy(month, getmonthname(m));
304 			sprintf(dayofmonth, "%d", d);
305 		}
306 		goto allfine;
307 	}
308 
309 fail:
310 	*p = pold;
311 	return (0);
312 allfine:
313 	*p = pold;
314 	return (1);
315 }
316 
317 static void
318 remember(int *rememberindex, int *y, int *m, int *d, char **ed, int yy, int mm,
319     int dd, char *extra)
320 {
321 	static int warned = 0;
322 
323 	if (*rememberindex >= MAXCOUNT - 1) {
324 		if (warned == 0)
325 			warnx("Index > %d, ignored", MAXCOUNT);
326 		warned++;
327 		return;
328 	}
329 	y[*rememberindex] = yy;
330 	m[*rememberindex] = mm;
331 	d[*rememberindex] = dd;
332 	if (extra != NULL)
333 		strcpy(ed[*rememberindex], extra);
334 	else
335 		ed[*rememberindex][0] = '\0';
336 	*rememberindex += 1;
337 }
338 
339 static void
340 debug_determinestyle(int dateonly, char *date, int flags, char *month,
341     int imonth, char *dayofmonth, int idayofmonth, char *dayofweek,
342     int idayofweek, char *modifieroffset, char *modifierindex, char *specialday,
343     char *year, int iyear)
344 {
345 	if (dateonly != 0) {
346 		printf("-------\ndate: |%s|\n", date);
347 		if (dateonly == 1)
348 			return;
349 	}
350 	printf("flags: %x - %s\n", flags, showflags(flags));
351 	if (modifieroffset[0] != '\0')
352 		printf("modifieroffset: |%s|\n", modifieroffset);
353 	if (modifierindex[0] != '\0')
354 		printf("modifierindex: |%s|\n", modifierindex);
355 	if (year[0] != '\0')
356 		printf("year: |%s| (%d)\n", year, iyear);
357 	if (month[0] != '\0')
358 		printf("month: |%s| (%d)\n", month, imonth);
359 	if (dayofmonth[0] != '\0')
360 		printf("dayofmonth: |%s| (%d)\n", dayofmonth, idayofmonth);
361 	if (dayofweek[0] != '\0')
362 		printf("dayofweek: |%s| (%d)\n", dayofweek, idayofweek);
363 	if (specialday[0] != '\0')
364 		printf("specialday: |%s|\n", specialday);
365 }
366 
367 static struct yearinfo {
368 	int year;
369 	int ieaster, ipaskha, firstcnyday;
370 	double ffullmoon[MAXMOONS], fnewmoon[MAXMOONS];
371 	double ffullmooncny[MAXMOONS], fnewmooncny[MAXMOONS];
372 	int ichinesemonths[MAXMOONS];
373 	double equinoxdays[2], solsticedays[2];
374 	int *monthdays;
375 	struct yearinfo *next;
376 } *years, *yearinfo;
377 
378 /*
379  * Calculate dates with offset from weekdays, like Thurs-3, Wed+2, etc.
380  * day is the day of the week,
381  * offset the ordinal number of the weekday in the month.
382  */
383 static int
384 wdayom(int day, int offset, int month, int year)
385 {
386 	int wday1;  /* Weekday of first day in month */
387 	int wdayn;  /* Weekday of first day in month */
388 	int d;
389 
390 	wday1 = first_dayofweek_of_month(year, month);
391 	if (wday1 < 0)                          /* not set */
392 		return (wday1);
393 
394 	/*
395 	 * Date of zeroth or first of our weekday in month, depending on the
396 	 * relationship with the first of the month.  The range is -6:6.
397 	 */
398 	d = (day - wday1 + 1) % 7;
399 	/*
400 	 * Which way are we counting?  Offset 0 is invalid, abs (offset) > 5 is
401 	 * meaningless, but that's OK.  Offset 5 may or may not be meaningless,
402 	 * so there's no point in complaining for complaining's sake.
403 	 */
404 	if (offset < 0) {			/* back from end of month */
405 						/* FIXME */
406 		wdayn = d;
407 		while (wdayn <= yearinfo->monthdays[month])
408 			wdayn += 7;
409 		d = offset * 7 + wdayn;
410 	} else if (offset > 0){
411 		if (d > 0)
412 			d += offset * 7 - 7;
413 		else
414 			d += offset * 7;
415 	} else {
416 		warnx ("Invalid offset 0");
417 	}
418 	return (d);
419 }
420 
421 /*
422  * Possible date formats include any combination of:
423  *	3-charmonth			(January, Jan, Jan)
424  *	3-charweekday			(Friday, Monday, mon.)
425  *	numeric month or day		(1, 2, 04)
426  *
427  * Any character may separate them, or they may not be separated.  Any line,
428  * following a line that is matched, that starts with "whitespace", is shown
429  * along with the matched line.
430  */
431 int
432 parsedaymonth(char *date, int *yearp, int *monthp, int *dayp, int *flags,
433     char **edp)
434 {
435 	char month[100], dayofmonth[100], dayofweek[100], modifieroffset[100];
436 	char syear[100];
437 	char modifierindex[100], specialday[100];
438 	int idayofweek = -1, imonth = -1, idayofmonth = -1, iyear = -1;
439 	int year, remindex;
440 	int d, m, dow, rm, rd, offset;
441 	char *ed;
442 	int retvalsign = 1;
443 
444 	/*
445 	 * CONVENTION
446 	 *
447 	 * Month:     1-12
448 	 * Monthname: Jan .. Dec
449 	 * Day:	      1-31
450 	 * Weekday:   Mon .. Sun
451 	 */
452 
453 	*flags = 0;
454 
455 	if (debug)
456 		debug_determinestyle(1, date, *flags, month, imonth,
457 		    dayofmonth, idayofmonth, dayofweek, idayofweek,
458 		    modifieroffset, modifierindex, specialday, syear, iyear);
459 	if (determinestyle(date, flags, month, &imonth, dayofmonth,
460 		&idayofmonth, dayofweek, &idayofweek, modifieroffset,
461 		modifierindex, specialday, syear, &iyear) == 0) {
462 		if (debug)
463 			printf("Failed!\n");
464 		return (0);
465 	}
466 
467 	if (debug)
468 		debug_determinestyle(0, date, *flags, month, imonth,
469 		    dayofmonth, idayofmonth, dayofweek, idayofweek,
470 		    modifieroffset, modifierindex, specialday, syear, iyear);
471 
472 	remindex = 0;
473 	for (year = year1; year <= year2; year++) {
474 
475 		int lflags = *flags;
476 		/* If the year is specified, only do it if it is this year! */
477 		if ((lflags & F_YEAR) != 0)
478 			if (iyear != year)
479 				continue;
480 		lflags &= ~F_YEAR;
481 
482 		/* Get important dates for this year */
483 		yearinfo = years;
484 		while (yearinfo != NULL) {
485 			if (yearinfo->year == year)
486 				break;
487 			yearinfo = yearinfo -> next;
488 		}
489 		if (yearinfo == NULL) {
490 			yearinfo = (struct yearinfo *)calloc(1,
491 			    sizeof(struct yearinfo));
492 			if (yearinfo == NULL)
493 				errx(1, "Unable to allocate more years");
494 			yearinfo->year = year;
495 			yearinfo->next = years;
496 			years = yearinfo;
497 
498 			yearinfo->monthdays = monthdaytab[isleap(year)];
499 			yearinfo->ieaster = easter(year);
500 			yearinfo->ipaskha = paskha(year);
501 			fpom(year, UTCOffset, yearinfo->ffullmoon,
502 			    yearinfo->fnewmoon);
503 			fpom(year, UTCOFFSET_CNY, yearinfo->ffullmooncny,
504 			    yearinfo->fnewmooncny);
505 			fequinoxsolstice(year, UTCOffset,
506 			    yearinfo->equinoxdays, yearinfo->solsticedays);
507 
508 			/*
509 			 * CNY: Match day with sun longitude at 330` with new
510 			 * moon
511 			 */
512 			yearinfo->firstcnyday = calculatesunlongitude30(year,
513 			    UTCOFFSET_CNY, yearinfo->ichinesemonths);
514 			for (m = 0; yearinfo->fnewmooncny[m] >= 0; m++) {
515 				if (yearinfo->fnewmooncny[m] >
516 				    yearinfo->firstcnyday) {
517 					yearinfo->firstcnyday =
518 					    floor(yearinfo->fnewmooncny[m - 1]);
519 					break;
520 				}
521 			}
522 		}
523 
524 		/* Same day every year */
525 		if (lflags == (F_MONTH | F_DAYOFMONTH)) {
526 			if (!remember_ymd(year, imonth, idayofmonth))
527 				continue;
528 			remember(&remindex, yearp, monthp, dayp, edp,
529 			    year, imonth, idayofmonth, NULL);
530 			continue;
531 		}
532 
533 		/* XXX Same day every year, but variable */
534 		if (lflags == (F_MONTH | F_DAYOFMONTH | F_VARIABLE)) {
535 			if (!remember_ymd(year, imonth, idayofmonth))
536 				continue;
537 			remember(&remindex, yearp, monthp, dayp, edp,
538 			    year, imonth, idayofmonth, NULL);
539 			continue;
540 		}
541 
542 		/* Same day every month */
543 		if (lflags == (F_ALLMONTH | F_DAYOFMONTH)) {
544 			for (m = 1; m <= 12; m++) {
545 				if (!remember_ymd(year, m, idayofmonth))
546 					continue;
547 				remember(&remindex, yearp, monthp, dayp, edp,
548 				    year, m, idayofmonth, NULL);
549 			}
550 			continue;
551 		}
552 
553 		/* Every day of a month */
554 		if (lflags == (F_ALLDAY | F_MONTH)) {
555 			for (d = 1; d <= yearinfo->monthdays[imonth]; d++) {
556 				if (!remember_ymd(year, imonth, d))
557 					continue;
558 				remember(&remindex, yearp, monthp, dayp, edp,
559 				    year, imonth, d, NULL);
560 			}
561 			continue;
562 		}
563 
564 		/* One day of every month */
565 		if (lflags == (F_ALLMONTH | F_DAYOFWEEK)) {
566 			for (m = 1; m <= 12; m++) {
567 				if (!remember_ymd(year, m, idayofmonth))
568 					continue;
569 				remember(&remindex, yearp, monthp, dayp, edp,
570 				    year, m, idayofmonth, NULL);
571 			}
572 			continue;
573 		}
574 
575 		/* Every dayofweek of the year */
576 		if (lflags == (F_DAYOFWEEK | F_VARIABLE)) {
577 			dow = first_dayofweek_of_year(year);
578 			d = (idayofweek - dow + 8) % 7;
579 			while (d <= 366) {
580 				if (remember_yd(year, d, &rm, &rd))
581 					remember(&remindex,
582 					    yearp, monthp, dayp, edp,
583 					    year, rm, rd, NULL);
584 				d += 7;
585 			}
586 			continue;
587 		}
588 
589 		/*
590 		 * Every so-manied dayofweek of every month of the year:
591 		 * Thu-3
592 		 */
593 		if (lflags == (F_DAYOFWEEK | F_MODIFIERINDEX | F_VARIABLE)) {
594 			offset = indextooffset(modifierindex);
595 
596 			for (m = 0; m <= 12; m++) {
597 	                        d = wdayom (idayofweek, offset, m, year);
598 				if (remember_ymd(year, m, d)) {
599 					remember(&remindex,
600 					    yearp, monthp, dayp, edp,
601 					    year, m, d, NULL);
602 					continue;
603 				}
604 			}
605 			continue;
606 		}
607 
608 		/*
609 		 * A certain dayofweek of a month
610 		 * Jan/Thu-3
611 		 */
612 		if (lflags ==
613 		    (F_MONTH | F_DAYOFWEEK | F_MODIFIERINDEX | F_VARIABLE)) {
614 			offset = indextooffset(modifierindex);
615 			dow = first_dayofweek_of_month(year, imonth);
616 			d = (idayofweek - dow + 8) % 7;
617 
618 			if (offset > 0) {
619 				while (d <= yearinfo->monthdays[imonth]) {
620 					if (--offset == 0
621 					    && remember_ymd(year, imonth, d)) {
622 						remember(&remindex,
623 						    yearp, monthp, dayp, edp,
624 						    year, imonth, d, NULL);
625 						continue;
626 					}
627 					d += 7;
628 				}
629 				continue;
630 			}
631 			if (offset < 0) {
632 				while (d <= yearinfo->monthdays[imonth])
633 					d += 7;
634 				while (offset != 0) {
635 					offset++;
636 					d -= 7;
637 				}
638 				if (remember_ymd(year, imonth, d))
639 					remember(&remindex,
640 					    yearp, monthp, dayp, edp,
641 					    year, imonth, d, NULL);
642 				continue;
643 			}
644 			continue;
645 		}
646 
647 		/* Every dayofweek of the month */
648 		if (lflags == (F_DAYOFWEEK | F_MONTH | F_VARIABLE)) {
649 			dow = first_dayofweek_of_month(year, imonth);
650 			d = (idayofweek - dow + 8) % 7;
651 			while (d <= yearinfo->monthdays[imonth]) {
652 				if (remember_ymd(year, imonth, d))
653 					remember(&remindex,
654 					    yearp, monthp, dayp, edp,
655 					    year, imonth, d, NULL);
656 				d += 7;
657 			}
658 			continue;
659 		}
660 
661 		/* Easter */
662 		if ((lflags & ~F_MODIFIEROFFSET) ==
663 		    (F_SPECIALDAY | F_VARIABLE | F_EASTER)) {
664 			offset = 0;
665 			if ((lflags & F_MODIFIEROFFSET) != 0)
666 				offset = parseoffset(modifieroffset);
667 			if (remember_yd(year, yearinfo->ieaster + offset,
668 					&rm, &rd)) {
669 				remember(&remindex, yearp, monthp, dayp, edp,
670 				    year, rm, rd, NULL);
671 			}
672 			continue;
673 		}
674 
675 		/* Paskha */
676 		if ((lflags & ~F_MODIFIEROFFSET) ==
677 		    (F_SPECIALDAY | F_VARIABLE | F_PASKHA)) {
678 			offset = 0;
679 			if ((lflags & F_MODIFIEROFFSET) != 0)
680 				offset = parseoffset(modifieroffset);
681 			if (remember_yd(year, yearinfo->ipaskha + offset,
682 					&rm, &rd)) {
683 				remember(&remindex, yearp, monthp, dayp, edp,
684 				    year, rm, rd, NULL);
685 			}
686 			continue;
687 		}
688 
689 		/* Chinese New Year */
690 		if ((lflags & ~F_MODIFIEROFFSET) ==
691 		    (F_SPECIALDAY | F_VARIABLE | F_CNY)) {
692 			offset = 0;
693 			if ((lflags & F_MODIFIEROFFSET) != 0)
694 				offset = parseoffset(modifieroffset);
695 			if (remember_yd(year, yearinfo->firstcnyday + offset,
696 					&rm, &rd)) {
697 				remember(&remindex, yearp, monthp, dayp, edp,
698 				    year, rm, rd, NULL);
699 			}
700 			continue;
701 		}
702 
703 		/* FullMoon */
704 		if ((lflags & ~F_MODIFIEROFFSET) ==
705 		    (F_SPECIALDAY | F_VARIABLE | F_FULLMOON)) {
706 			int i;
707 
708 			offset = 0;
709 			if ((lflags & F_MODIFIEROFFSET) != 0)
710 				offset = parseoffset(modifieroffset);
711 			for (i = 0; yearinfo->ffullmoon[i] > 0; i++) {
712 				if (remember_yd(year,
713 				    floor(yearinfo->ffullmoon[i]) + offset,
714 				    &rm, &rd)) {
715 					ed = floattotime(
716 					    yearinfo->ffullmoon[i]);
717 					remember(&remindex,
718 					    yearp, monthp, dayp, edp,
719 					    year, rm, rd, ed);
720 				}
721 			}
722 			continue;
723 		}
724 
725 		/* NewMoon */
726 		if ((lflags & ~F_MODIFIEROFFSET) ==
727 		    (F_SPECIALDAY | F_VARIABLE | F_NEWMOON)) {
728 			int i;
729 
730 			offset = 0;
731 			if ((lflags & F_MODIFIEROFFSET) != 0)
732 				offset = parseoffset(modifieroffset);
733 			for (i = 0; yearinfo->ffullmoon[i] > 0; i++) {
734 				if (remember_yd(year,
735 				    floor(yearinfo->fnewmoon[i]) + offset,
736 				    &rm, &rd)) {
737 					ed = floattotime(yearinfo->fnewmoon[i]);
738 					remember(&remindex,
739 					    yearp, monthp, dayp, edp,
740 					    year, rm, rd, ed);
741 				}
742 			}
743 			continue;
744 		}
745 
746 		/* (Mar|Sep)Equinox */
747 		if ((lflags & ~F_MODIFIEROFFSET) ==
748 		    (F_SPECIALDAY | F_VARIABLE | F_MAREQUINOX)) {
749 			offset = 0;
750 			if ((lflags & F_MODIFIEROFFSET) != 0)
751 				offset = parseoffset(modifieroffset);
752 			if (remember_yd(year, yearinfo->equinoxdays[0] + offset,
753 					&rm, &rd)) {
754 				ed = floattotime(yearinfo->equinoxdays[0]);
755 				remember(&remindex, yearp, monthp, dayp, edp,
756 				    year, rm, rd, ed);
757 			}
758 			continue;
759 		}
760 		if ((lflags & ~F_MODIFIEROFFSET) ==
761 		    (F_SPECIALDAY | F_VARIABLE | F_SEPEQUINOX)) {
762 			offset = 0;
763 			if ((lflags & F_MODIFIEROFFSET) != 0)
764 				offset = parseoffset(modifieroffset);
765 			if (remember_yd(year, yearinfo->equinoxdays[1] + offset,
766 					&rm, &rd)) {
767 				ed = floattotime(yearinfo->equinoxdays[1]);
768 				remember(&remindex, yearp, monthp, dayp, edp,
769 				    year, rm, rd, ed);
770 			}
771 			continue;
772 		}
773 
774 		/* (Jun|Dec)Solstice */
775 		if ((lflags & ~F_MODIFIEROFFSET) ==
776 		    (F_SPECIALDAY | F_VARIABLE | F_JUNSOLSTICE)) {
777 			offset = 0;
778 			if ((lflags & F_MODIFIEROFFSET) != 0)
779 				offset = parseoffset(modifieroffset);
780 			if (remember_yd(year,
781 			    yearinfo->solsticedays[0] + offset, &rm, &rd)) {
782 				ed = floattotime(yearinfo->solsticedays[0]);
783 				remember(&remindex, yearp, monthp, dayp, edp,
784 				    year, rm, rd, ed);
785 			}
786 			continue;
787 		}
788 		if ((lflags & ~F_MODIFIEROFFSET) ==
789 		    (F_SPECIALDAY | F_VARIABLE | F_DECSOLSTICE)) {
790 			offset = 0;
791 			if ((lflags & F_MODIFIEROFFSET) != 0)
792 				offset = parseoffset(modifieroffset);
793 			if (remember_yd(year,
794 			    yearinfo->solsticedays[1] + offset, &rm, &rd)) {
795 				ed = floattotime(yearinfo->solsticedays[1]);
796 				remember(&remindex, yearp, monthp, dayp, edp,
797 				    year, rm, rd, ed);
798 			}
799 			continue;
800 		}
801 
802 		if (debug) {
803 			printf("Unprocessed:\n");
804 			debug_determinestyle(2, date, lflags, month, imonth,
805 			    dayofmonth, idayofmonth, dayofweek, idayofweek,
806 			    modifieroffset, modifierindex, specialday, syear,
807 			    iyear);
808 		}
809 		retvalsign = -1;
810 	}
811 
812 	if (retvalsign == -1)
813 		return (-remindex - 1);
814 	else
815 		return (remindex);
816 }
817 
818 static char *
819 showflags(int flags)
820 {
821 	static char s[1000];
822 	s[0] = '\0';
823 
824 	if ((flags & F_YEAR) != 0)
825 		strcat(s, "year ");
826 	if ((flags & F_MONTH) != 0)
827 		strcat(s, "month ");
828 	if ((flags & F_DAYOFWEEK) != 0)
829 		strcat(s, "dayofweek ");
830 	if ((flags & F_DAYOFMONTH) != 0)
831 		strcat(s, "dayofmonth ");
832 	if ((flags & F_MODIFIERINDEX) != 0)
833 		strcat(s, "modifierindex ");
834 	if ((flags & F_MODIFIEROFFSET) != 0)
835 		strcat(s, "modifieroffset ");
836 	if ((flags & F_SPECIALDAY) != 0)
837 		strcat(s, "specialday ");
838 	if ((flags & F_ALLMONTH) != 0)
839 		strcat(s, "allmonth ");
840 	if ((flags & F_ALLDAY) != 0)
841 		strcat(s, "allday ");
842 	if ((flags & F_VARIABLE) != 0)
843 		strcat(s, "variable ");
844 	if ((flags & F_CNY) != 0)
845 		strcat(s, "chinesenewyear ");
846 	if ((flags & F_PASKHA) != 0)
847 		strcat(s, "paskha ");
848 	if ((flags & F_EASTER) != 0)
849 		strcat(s, "easter ");
850 	if ((flags & F_FULLMOON) != 0)
851 		strcat(s, "fullmoon ");
852 	if ((flags & F_NEWMOON) != 0)
853 		strcat(s, "newmoon ");
854 	if ((flags & F_MAREQUINOX) != 0)
855 		strcat(s, "marequinox ");
856 	if ((flags & F_SEPEQUINOX) != 0)
857 		strcat(s, "sepequinox ");
858 	if ((flags & F_JUNSOLSTICE) != 0)
859 		strcat(s, "junsolstice ");
860 	if ((flags & F_DECSOLSTICE) != 0)
861 		strcat(s, "decsolstice ");
862 
863 	return s;
864 }
865 
866 static const char *
867 getmonthname(int i)
868 {
869 	if (i <= 0 || i > 12)
870 		return ("");
871 	if (nmonths[i - 1].len != 0 && nmonths[i - 1].name != NULL)
872 		return (nmonths[i - 1].name);
873 	return (months[i - 1]);
874 }
875 
876 static int
877 checkmonth(char *s, size_t *len, size_t *offset, const char **month)
878 {
879 	struct fixs *n;
880 	int i;
881 
882 	for (i = 0; fnmonths[i].name != NULL; i++) {
883 		n = fnmonths + i;
884 		if (strncasecmp(s, n->name, n->len) == 0) {
885 			*len = n->len;
886 			*month = n->name;
887 			*offset = i + 1;
888 			return (1);
889 		}
890 	}
891 	for (i = 0; nmonths[i].name != NULL; i++) {
892 		n = nmonths + i;
893 		if (strncasecmp(s, n->name, n->len) == 0) {
894 			*len = n->len;
895 			*month = n->name;
896 			*offset = i + 1;
897 			return (1);
898 		}
899 	}
900 	for (i = 0; fmonths[i] != NULL; i++) {
901 		*len = strlen(fmonths[i]);
902 		if (strncasecmp(s, fmonths[i], *len) == 0) {
903 			*month = fmonths[i];
904 			*offset = i + 1;
905 			return (1);
906 		}
907 	}
908 	for (i = 0; months[i] != NULL; i++) {
909 		if (strncasecmp(s, months[i], 3) == 0) {
910 			*len = 3;
911 			*month = months[i];
912 			*offset = i + 1;
913 			return (1);
914 		}
915 	}
916 	return (0);
917 }
918 
919 static const char *
920 getdayofweekname(int i)
921 {
922 	if (ndays[i].len != 0 && ndays[i].name != NULL)
923 		return (ndays[i].name);
924 	return (days[i]);
925 }
926 
927 static int
928 checkdayofweek(char *s, size_t *len, size_t *offset, const char **dow)
929 {
930 	struct fixs *n;
931 	int i;
932 
933 	for (i = 0; fndays[i].name != NULL; i++) {
934 		n = fndays + i;
935 		if (strncasecmp(s, n->name, n->len) == 0) {
936 			*len = n->len;
937 			*dow = n->name;
938 			*offset = i;
939 			return (1);
940 		}
941 	}
942 	for (i = 0; ndays[i].name != NULL; i++) {
943 		n = ndays + i;
944 		if (strncasecmp(s, n->name, n->len) == 0) {
945 			*len = n->len;
946 			*dow = n->name;
947 			*offset = i;
948 			return (1);
949 		}
950 	}
951 	for (i = 0; fdays[i] != NULL; i++) {
952 		*len = strlen(fdays[i]);
953 		if (strncasecmp(s, fdays[i], *len) == 0) {
954 			*dow = fdays[i];
955 			*offset = i;
956 			return (1);
957 		}
958 	}
959 	for (i = 0; days[i] != NULL; i++) {
960 		if (strncasecmp(s, days[i], 3) == 0) {
961 			*len = 3;
962 			*dow = days[i];
963 			*offset = i;
964 			return (1);
965 		}
966 	}
967 	return (0);
968 }
969 
970 static bool
971 isonlydigits(char *s, int nostar)
972 {
973 	int i;
974 	for (i = 0; s[i] != '\0'; i++) {
975 		if (nostar == 0 && s[i] == '*' && s[i + 1] == '\0')
976 			return (true);
977 		if (!isdigit((unsigned char)s[i]))
978 			return (false);
979 	}
980 	return (true);
981 }
982 
983 static int
984 indextooffset(char *s)
985 {
986 	int i;
987 	struct fixs *n;
988 	char *es;
989 
990 	if (s[0] == '+' || s[0] == '-') {
991 		i = strtol (s, &es, 10);
992 		if (*es != '\0')                      /* trailing junk */
993 			errx (1, "Invalid specifier format: %s\n", s);
994 		return (i);
995 	}
996 
997 	for (i = 0; i < 6; i++) {
998 		if (strcasecmp(s, sequences[i]) == 0) {
999 			if (i == 5)
1000 				return (-1);
1001 			return (i + 1);
1002 		}
1003 	}
1004 	for (i = 0; i < 6; i++) {
1005 		n = nsequences + i;
1006 		if (n->len == 0)
1007 			continue;
1008 		if (strncasecmp(s, n->name, n->len) == 0) {
1009 			if (i == 5)
1010 				return (-1);
1011 			return (i + 1);
1012 		}
1013 	}
1014 	return (0);
1015 }
1016 
1017 static int
1018 parseoffset(char *s)
1019 {
1020 	return strtol(s, NULL, 10);
1021 }
1022 
1023 static char *
1024 floattotime(double f)
1025 {
1026 	static char buf[100];
1027 	int hh, mm, ss, i;
1028 
1029 	f -= floor(f);
1030 	i = f * SECSPERDAY;
1031 
1032 	hh = i / SECSPERHOUR;
1033 	i %= SECSPERHOUR;
1034 	mm = i / SECSPERMINUTE;
1035 	i %= SECSPERMINUTE;
1036 	ss = i;
1037 
1038 	sprintf(buf, "%02d:%02d:%02d", hh, mm, ss);
1039 	return (buf);
1040 }
1041 
1042 static char *
1043 floattoday(int year, double f)
1044 {
1045 	static char buf[100];
1046 	int i, m, d, hh, mm, ss;
1047 	int *cumdays = cumdaytab[isleap(year)];
1048 
1049 	for (i = 0; 1 + cumdays[i] < f; i++)
1050 		;
1051 	m = --i;
1052 	d = floor(f - 1 - cumdays[i]);
1053 	f -= floor(f);
1054 	i = f * SECSPERDAY;
1055 
1056 	hh = i / SECSPERHOUR;
1057 	i %= SECSPERHOUR;
1058 	mm = i / SECSPERMINUTE;
1059 	i %= SECSPERMINUTE;
1060 	ss = i;
1061 
1062 	sprintf(buf, "%02d-%02d %02d:%02d:%02d", m, d, hh, mm, ss);
1063 	return (buf);
1064 }
1065 
1066 void
1067 dodebug(char *what)
1068 {
1069 	int year;
1070 
1071 	printf("UTCOffset: %g\n", UTCOffset);
1072 	printf("EastLongitude: %g\n", EastLongitude);
1073 
1074 	if (strcmp(what, "moon") == 0) {
1075 		double ffullmoon[MAXMOONS], fnewmoon[MAXMOONS];
1076 		int i;
1077 
1078 		for (year = year1; year <= year2; year++) {
1079 			fpom(year, UTCOffset, ffullmoon, fnewmoon);
1080 			printf("Full moon %d:\t", year);
1081 			for (i = 0; ffullmoon[i] >= 0; i++) {
1082 				printf("%g (%s) ", ffullmoon[i],
1083 				    floattoday(year, ffullmoon[i]));
1084 			}
1085 			printf("\nNew moon %d:\t", year);
1086 			for (i = 0; fnewmoon[i] >= 0; i++) {
1087 				printf("%g (%s) ", fnewmoon[i],
1088 				    floattoday(year, fnewmoon[i]));
1089 			}
1090 			printf("\n");
1091 		}
1092 		return;
1093 	}
1094 
1095 	if (strcmp(what, "sun") == 0) {
1096 		double equinoxdays[2], solsticedays[2];
1097 		for (year = year1; year <= year2; year++) {
1098 			printf("Sun in %d:\n", year);
1099 			fequinoxsolstice(year, UTCOffset, equinoxdays,
1100 			    solsticedays);
1101 			printf("e[0] - %g (%s)\n",
1102 			    equinoxdays[0],
1103 			    floattoday(year, equinoxdays[0]));
1104 			printf("e[1] - %g (%s)\n",
1105 			    equinoxdays[1],
1106 			    floattoday(year, equinoxdays[1]));
1107 			printf("s[0] - %g (%s)\n",
1108 			    solsticedays[0],
1109 			    floattoday(year, solsticedays[0]));
1110 			printf("s[1] - %g (%s)\n",
1111 			    solsticedays[1],
1112 			    floattoday(year, solsticedays[1]));
1113 		}
1114 		return;
1115 	}
1116 }
1117