xref: /netbsd-src/usr.bin/cal/cal.c (revision d48f14661dda8638fee055ba15d35bdfb29b9fa8)
1 /*	$NetBSD: cal.c,v 1.19 2005/06/02 01:38:50 lukem Exp $	*/
2 
3 /*
4  * Copyright (c) 1989, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Kim Letkeman.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 
35 #include <sys/cdefs.h>
36 #ifndef lint
37 __COPYRIGHT("@(#) Copyright (c) 1989, 1993, 1994\n\
38 	The Regents of the University of California.  All rights reserved.\n");
39 #endif /* not lint */
40 
41 #ifndef lint
42 #if 0
43 static char sccsid[] = "@(#)cal.c	8.4 (Berkeley) 4/2/94";
44 #else
45 __RCSID("$NetBSD: cal.c,v 1.19 2005/06/02 01:38:50 lukem Exp $");
46 #endif
47 #endif /* not lint */
48 
49 #include <sys/types.h>
50 
51 #include <ctype.h>
52 #include <err.h>
53 #include <errno.h>
54 #include <limits.h>
55 #include <stdio.h>
56 #include <stdlib.h>
57 #include <string.h>
58 #include <termcap.h>
59 #include <time.h>
60 #include <tzfile.h>
61 #include <unistd.h>
62 
63 #define	SATURDAY 		6		/* 1 Jan 1 was a Saturday */
64 
65 #define	FIRST_MISSING_DAY 	reform->first_missing_day
66 #define	NUMBER_MISSING_DAYS 	reform->missing_days
67 
68 #define	MAXDAYS			42		/* max slots in a month array */
69 #define	SPACE			-1		/* used in day array */
70 
71 static int days_in_month[2][13] = {
72 	{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
73 	{0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
74 };
75 
76 int empty[MAXDAYS] = {
77 	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
78 	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
79 	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
80 	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
81 	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
82 	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
83 };
84 int shift_days[2][4][MAXDAYS + 1];
85 
86 char *month_names[12] = {
87 	"January", "February", "March", "April", "May", "June",
88 	"July", "August", "September", "October", "November", "December",
89 };
90 
91 char *day_headings = " S  M Tu  W Th  F  S";
92 char *j_day_headings = "  S   M  Tu   W  Th   F   S";
93 
94 /* leap years according to the julian calendar */
95 #define j_leap_year(y, m, d) \
96 	(((m) > 2) && \
97 	 !((y) % 4))
98 
99 /* leap years according to the gregorian calendar */
100 #define g_leap_year(y, m, d) \
101 	(((m) > 2) && \
102 	 ((!((y) % 4) && ((y) % 100)) || \
103 	  !((y) % 400)))
104 
105 /* leap year -- account for gregorian reformation at some point */
106 #define	leap_year(yr) \
107 	((yr) <= reform->year ? j_leap_year((yr), 3, 1) : \
108 	g_leap_year((yr), 3, 1))
109 
110 /* number of julian leap days that have passed by a given date */
111 #define j_leap_days(y, m, d) \
112 	((((y) - 1) / 4) + j_leap_year(y, m, d))
113 
114 /* number of gregorian leap days that have passed by a given date */
115 #define g_leap_days(y, m, d) \
116 	((((y) - 1) / 4) - (((y) - 1) / 100) + (((y) - 1) / 400) + \
117 	g_leap_year(y, m, d))
118 
119 /*
120  * Subtracting the gregorian leap day count (for a given date) from
121  * the julian leap day count (for the same date) describes the number
122  * of days from the date before the shift to the next date that
123  * appears in the calendar.  Since we want to know the number of
124  * *missing* days, not the number of days that the shift spans, we
125  * subtract 2.
126  *
127  * Alternately...
128  *
129  * There's a reason they call the Dark ages the Dark Ages.  Part of it
130  * is that we don't have that many records of that period of time.
131  * One of the reasons for this is that a lot of the Dark Ages never
132  * actually took place.  At some point in the first millenium A.D., a
133  * ruler of some power decided that he wanted the number of the year
134  * to be different than what it was, so he changed it to coincide
135  * nicely with some event (a birthday or anniversary, perhaps a
136  * wedding, or maybe a centennial for a largish city).  One of the
137  * side effects of this upon the Gregorian reform is that two Julian
138  * leap years (leap days celebrated during centennial years that are
139  * not quatro-centennial years) were skipped.
140  */
141 #define GREGORIAN_MAGIC 2
142 
143 /* number of centuries since the reform, not inclusive */
144 #define	centuries_since_reform(yr) \
145 	((yr) > reform->year ? ((yr) / 100) - (reform->year / 100) : 0)
146 
147 /* number of centuries since the reform whose modulo of 400 is 0 */
148 #define	quad_centuries_since_reform(yr) \
149 	((yr) > reform->year ? ((yr) / 400) - (reform->year / 400) : 0)
150 
151 /* number of leap years between year 1 and this year, not inclusive */
152 #define	leap_years_since_year_1(yr) \
153 	((yr) / 4 - centuries_since_reform(yr) + quad_centuries_since_reform(yr))
154 
155 struct reform {
156 	const char *country;
157 	int ambiguity, year, month, date;
158 	long first_missing_day;
159 	int missing_days;
160 	/*
161 	 * That's 2 for standard/julian display, 4 for months possibly
162 	 * affected by the Gregorian shift, and MAXDAYS + 1 for the
163 	 * days that get displayed, plus a crib slot.
164 	 */
165 } *reform, reforms[] = {
166 	{ "DEFAULT",		0, 1752,  9,  3 },
167 	{ "Italy",		1, 1582, 10,  5 },
168 	{ "Spain",		1, 1582, 10,  5 },
169 	{ "Portugal",		1, 1582, 10,  5 },
170 	{ "Poland",		1, 1582, 10,  5 },
171 	{ "France",		2, 1582, 12, 10 },
172 	{ "Luxembourg",		2, 1582, 12, 22 },
173 	{ "Netherlands",	2, 1582, 12, 22 },
174 	{ "Bavaria",		0, 1583, 10,  6 },
175 	{ "Austria",		2, 1584,  1,  7 },
176 	{ "Switzerland",	2, 1584,  1, 12 },
177 	{ "Hungary",		0, 1587, 10, 22 },
178 	{ "Germany",		0, 1700,  2, 19 },
179 	{ "Norway",		0, 1700,  2, 19 },
180 	{ "Denmark",		0, 1700,  2, 19 },
181 	{ "Great Britain",	0, 1752,  9,  3 },
182 	{ "England",		0, 1752,  9,  3 },
183 	{ "America",		0, 1752,  9,  3 },
184 	{ "Sweden",		0, 1753,  2, 18 },
185 	{ "Finland",		0, 1753,  2, 18 },
186 	{ "Japan",		0, 1872, 12, 20 },
187 	{ "China",		0, 1911, 11,  7 },
188 	{ "Bulgaria",		0, 1916,  4,  1 },
189 	{ "U.S.S.R.",		0, 1918,  2,  1 },
190 	{ "Serbia",		0, 1919,  1, 19 },
191 	{ "Romania",		0, 1919,  1, 19 },
192 	{ "Greece",		0, 1924,  3, 10 },
193 	{ "Turkey",		0, 1925, 12, 19 },
194 	{ "Egypt",		0, 1928,  9, 18 },
195 	{ NULL,			0,    0,  0,  0 },
196 };
197 
198 int julian;
199 int dow;
200 int hilite;
201 char *md, *me;
202 
203 void	init_hilite(void);
204 int	getnum(const char *);
205 void	gregorian_reform(const char *);
206 void	reform_day_array(int, int, int *, int *, int *,int *,int *,int *);
207 int	ascii_day(char *, int);
208 void	center(char *, int, int);
209 void	day_array(int, int, int *);
210 int	day_in_week(int, int, int);
211 int	day_in_year(int, int, int);
212 void	monthrange(int, int, int, int, int);
213 int	main(int, char **);
214 void	trim_trailing_spaces(char *);
215 void	usage(void);
216 
217 int
218 main(int argc, char **argv)
219 {
220 	struct tm *local_time;
221 	time_t now;
222 	int ch, month, year, yflag;
223 	int before, after, use_reform;
224 	int yearly = 0;
225 	char *when;
226 
227 	before = after = 0;
228 	use_reform = yflag = year = 0;
229 	when = NULL;
230 	while ((ch = getopt(argc, argv, "A:B:d:hjR:ry3")) != -1) {
231 		switch (ch) {
232 		case 'A':
233 			after = getnum(optarg);
234 			break;
235 		case 'B':
236 			before = getnum(optarg);
237 			break;
238 		case 'd':
239 			dow = getnum(optarg);
240 			if (dow < 0 || dow > 6)
241 				errx(1, "illegal day of week value: use 0-6");
242 			break;
243 		case 'h':
244 			init_hilite();
245 			break;
246 		case 'j':
247 			julian = 1;
248 			break;
249 		case 'R':
250 			when = optarg;
251 			break;
252 		case 'r':
253 			use_reform = 1;
254 			break;
255 		case 'y':
256 			yflag = 1;
257 			break;
258 		case '3':
259 			before = after = 1;
260 			break;
261 		case '?':
262 		default:
263 			usage();
264 			/* NOTREACHED */
265 		}
266 	}
267 
268 	argc -= optind;
269 	argv += optind;
270 
271 	if (when != NULL)
272 		gregorian_reform(when);
273 	if (reform == NULL)
274 		gregorian_reform("DEFAULT");
275 
276 	month = 0;
277 	switch (argc) {
278 	case 2:
279 		if ((month = atoi(*argv++)) < 1 || month > 12)
280 			errx(1, "illegal month value: use 1-12");
281 		/* FALLTHROUGH */
282 	case 1:
283 		if ((year = atoi(*argv)) < 1 || year > 9999)
284 			errx(1, "illegal year value: use 1-9999");
285 		break;
286 	case 0:
287 		(void)time(&now);
288 		local_time = localtime(&now);
289 		if (use_reform)
290 			year = reform->year;
291 		else
292 			year = local_time->tm_year + TM_YEAR_BASE;
293 		if (!yflag) {
294 			if (use_reform)
295 				month = reform->month;
296 			else
297 				month = local_time->tm_mon + 1;
298 		}
299 		break;
300 	default:
301 		usage();
302 	}
303 
304 	if (!month) {
305 		/* yearly */
306 		month = 1;
307 		before = 0;
308 		after = 11;
309 		yearly = 1;
310 	}
311 
312 	monthrange(month, year, before, after, yearly);
313 
314 	exit(0);
315 }
316 
317 #define	DAY_LEN		3		/* 3 spaces per day */
318 #define	J_DAY_LEN	4		/* 4 spaces per day */
319 #define	WEEK_LEN	20		/* 7 * 3 - one space at the end */
320 #define	J_WEEK_LEN	27		/* 7 * 4 - one space at the end */
321 #define	HEAD_SEP	2		/* spaces between day headings */
322 #define	J_HEAD_SEP	2
323 #define	MONTH_PER_ROW	3		/* how many monthes in a row */
324 #define	J_MONTH_PER_ROW	2
325 
326 void
327 monthrange(int month, int year, int before, int after, int yearly)
328 {
329 	int startmonth, startyear;
330 	int endmonth, endyear;
331 	int i, row;
332 	int days[3][MAXDAYS];
333 	char lineout[256];
334 	int inayear;
335 	int newyear;
336 	int day_len, week_len, head_sep;
337 	int month_per_row;
338 	int skip, r_off, w_off;
339 
340 	if (julian) {
341 		day_len = J_DAY_LEN;
342 		week_len = J_WEEK_LEN;
343 		head_sep = J_HEAD_SEP;
344 		month_per_row = J_MONTH_PER_ROW;
345 	}
346 	else {
347 		day_len = DAY_LEN;
348 		week_len = WEEK_LEN;
349 		head_sep = HEAD_SEP;
350 		month_per_row = MONTH_PER_ROW;
351 	}
352 
353 	month--;
354 
355 	startyear = year - (before + 12 - 1 - month) / 12;
356 	startmonth = 12 - 1 - ((before + 12 - 1 - month) % 12);
357 	endyear = year + (month + after) / 12;
358 	endmonth = (month + after) % 12;
359 
360 	if (startyear < 0 || endyear > 9999) {
361 		errx(1, "year should be in 1-9999\n");
362 	}
363 
364 	year = startyear;
365 	month = startmonth;
366 	inayear = newyear = (year != endyear || yearly);
367 	if (inayear) {
368 		skip = month % month_per_row;
369 		month -= skip;
370 	}
371 	else {
372 		skip = 0;
373 	}
374 
375 	do {
376 		if (newyear) {
377 			(void)snprintf(lineout, sizeof(lineout), "%d", year);
378 			center(lineout, week_len * month_per_row +
379 			    head_sep * (month_per_row - 1), 0);
380 			(void)printf("\n\n");
381 			newyear = 0;
382 		}
383 
384 		for (i = 0; i < skip; i++)
385 			center("", week_len, head_sep);
386 
387 		for (; i < month_per_row; i++) {
388 			int sep;
389 
390 			if (year == endyear && month + i > endmonth)
391 				break;
392 
393 			sep = (i == month_per_row - 1) ? 0 : head_sep;
394 			day_array(month + i + 1, year, days[i]);
395 			if (inayear) {
396 				center(month_names[month + i], week_len, sep);
397 			}
398 			else {
399 				snprintf(lineout, sizeof(lineout), "%s %d",
400 				    month_names[month + i], year);
401 				center(lineout, week_len, sep);
402 			}
403 		}
404 		printf("\n");
405 
406 		for (i = 0; i < skip; i++)
407 			center("", week_len, head_sep);
408 
409 		for (; i < month_per_row; i++) {
410 			int sep;
411 
412 			if (year == endyear && month + i > endmonth)
413 				break;
414 
415 			sep = (i == month_per_row - 1) ? 0 : head_sep;
416 			if (dow) {
417 				printf("%s ", (julian) ?
418 				    j_day_headings + 4 * dow :
419 				    day_headings + 3 * dow);
420 				printf("%.*s", dow * (julian ? 4 : 3) - 1,
421 				       (julian) ? j_day_headings : day_headings);
422 			} else
423 				printf("%s", (julian) ? j_day_headings : day_headings);
424 			printf("%*s", sep, "");
425 		}
426 		printf("\n");
427 
428 		for (row = 0; row < 6; row++) {
429 			char *p = NULL;
430 
431 			memset(lineout, ' ', sizeof(lineout));
432 			for (i = 0; i < skip; i++) {
433 				/* nothing */
434 			}
435 			w_off = 0;
436 			for (; i < month_per_row; i++) {
437 				int col, *dp;
438 
439 				if (year == endyear && month + i > endmonth)
440 					break;
441 
442 				p = lineout + i * (week_len + 2) + w_off;
443 				dp = &days[i][row * 7];
444 				for (col = 0; col < 7;
445 				     col++, p += day_len + r_off) {
446 					r_off = ascii_day(p, *dp++);
447 					w_off += r_off;
448 				}
449 			}
450 			*p = '\0';
451 			trim_trailing_spaces(lineout);
452 			(void)printf("%s\n", lineout);
453 		}
454 
455 		skip = 0;
456 		month += month_per_row;
457 		if (month >= 12) {
458 			month -= 12;
459 			year++;
460 			newyear = 1;
461 		}
462 	} while (year < endyear || (year == endyear && month <= endmonth));
463 }
464 
465 /*
466  * day_array --
467  *	Fill in an array of 42 integers with a calendar.  Assume for a moment
468  *	that you took the (maximum) 6 rows in a calendar and stretched them
469  *	out end to end.  You would have 42 numbers or spaces.  This routine
470  *	builds that array for any month from Jan. 1 through Dec. 9999.
471  */
472 void
473 day_array(int month, int year, int *days)
474 {
475 	int day, dw, dm;
476 	time_t t;
477 	struct tm *tm;
478 
479 	t = time(NULL);
480 	tm = localtime(&t);
481 	tm->tm_year += TM_YEAR_BASE;
482 	tm->tm_mon++;
483 	tm->tm_yday++; /* jan 1 is 1 for us, not 0 */
484 
485 	for (dm = month + year * 12, dw = 0; dw < 4; dw++) {
486 		if (dm == shift_days[julian][dw][MAXDAYS]) {
487 			memmove(days, shift_days[julian][dw],
488 				MAXDAYS * sizeof(int));
489 			return;
490 		}
491 	}
492 
493 	memmove(days, empty, MAXDAYS * sizeof(int));
494 	dm = days_in_month[leap_year(year)][month];
495 	dw = day_in_week(1, month, year);
496 	day = julian ? day_in_year(1, month, year) : 1;
497 	while (dm--) {
498 		if (hilite && year == tm->tm_year &&
499 		    (julian ? (day == tm->tm_yday) :
500 		     (month == tm->tm_mon && day == tm->tm_mday)))
501 			days[dw++] = SPACE - day++;
502 		else
503 			days[dw++] = day++;
504 	}
505 }
506 
507 /*
508  * day_in_year --
509  *	return the 1 based day number within the year
510  */
511 int
512 day_in_year(int day, int month, int year)
513 {
514 	int i, leap;
515 
516 	leap = leap_year(year);
517 	for (i = 1; i < month; i++)
518 		day += days_in_month[leap][i];
519 	return (day);
520 }
521 
522 /*
523  * day_in_week
524  *	return the 0 based day number for any date from 1 Jan. 1 to
525  *	31 Dec. 9999.  Returns the day of the week of the first
526  *	missing day for any given Gregorian shift.
527  */
528 int
529 day_in_week(int day, int month, int year)
530 {
531 	long temp;
532 
533 	temp = (long)(year - 1) * 365 + leap_years_since_year_1(year - 1)
534 	    + day_in_year(day, month, year);
535 	if (temp < FIRST_MISSING_DAY)
536 		return ((temp - dow + 6 + SATURDAY) % 7);
537 	if (temp >= (FIRST_MISSING_DAY + NUMBER_MISSING_DAYS))
538 		return (((temp - dow + 6 + SATURDAY) - NUMBER_MISSING_DAYS) % 7);
539 	return ((FIRST_MISSING_DAY - dow + 6 + SATURDAY) % 7);
540 }
541 
542 int
543 ascii_day(char *p, int day)
544 {
545 	int display, val, rc;
546 	char *b;
547 	static char *aday[] = {
548 		"",
549 		" 1", " 2", " 3", " 4", " 5", " 6", " 7",
550 		" 8", " 9", "10", "11", "12", "13", "14",
551 		"15", "16", "17", "18", "19", "20", "21",
552 		"22", "23", "24", "25", "26", "27", "28",
553 		"29", "30", "31",
554 	};
555 
556 	if (day == SPACE) {
557 		memset(p, ' ', julian ? J_DAY_LEN : DAY_LEN);
558 		return (0);
559 	}
560 	if (day < SPACE) {
561 		b = p;
562 		day = SPACE - day;
563 	} else
564 		b = NULL;
565 	if (julian) {
566 		if ((val = day / 100) != 0) {
567 			day %= 100;
568 			*p++ = val + '0';
569 			display = 1;
570 		} else {
571 			*p++ = ' ';
572 			display = 0;
573 		}
574 		val = day / 10;
575 		if (val || display)
576 			*p++ = val + '0';
577 		else
578 			*p++ = ' ';
579 		*p++ = day % 10 + '0';
580 	} else {
581 		*p++ = aday[day][0];
582 		*p++ = aday[day][1];
583 	}
584 
585 	rc = 0;
586 	if (b != NULL) {
587 		char *t, h[64];
588 		int l;
589 
590 		l = p - b;
591 		memcpy(h, b, l);
592 		p = b;
593 
594 		if (md != NULL) {
595 			for (t = md; *t; rc++)
596 				*p++ = *t++;
597 			memcpy(p, h, l);
598 			p += l;
599 			for (t = me; *t; rc++)
600 				*p++ = *t++;
601 		} else {
602 			for (t = &h[0]; l--; t++) {
603 				*p++ = *t;
604 				rc++;
605 				*p++ = '\b';
606 				rc++;
607 				*p++ = *t;
608 			}
609 		}
610 	}
611 
612 	*p = ' ';
613 	return (rc);
614 }
615 
616 void
617 trim_trailing_spaces(char *s)
618 {
619 	char *p;
620 
621 	for (p = s; *p; ++p)
622 		continue;
623 	while (p > s && isspace((unsigned char)*--p))
624 		continue;
625 	if (p > s)
626 		++p;
627 	*p = '\0';
628 }
629 
630 void
631 center(char *str, int len, int separate)
632 {
633 
634 	len -= strlen(str);
635 	(void)printf("%*s%s%*s", len / 2, "", str, len / 2 + len % 2, "");
636 	if (separate)
637 		(void)printf("%*s", separate, "");
638 }
639 
640 /*
641  * gregorian_reform --
642  *	Given a description of date on which the Gregorian Reform was
643  *	applied.  The argument can be any of the "country" names
644  *	listed in the reforms array (case insensitive) or a date of
645  *	the form YYYY/MM/DD.  The date and month can be omitted if
646  *	doing so would not select more than one different built-in
647  *	reform point.
648  */
649 void
650 gregorian_reform(const char *p)
651 {
652 	int year, month, date;
653 	int i, days, diw, diy;
654 	char c;
655 
656 	i = sscanf(p, "%d%*[/,-]%d%*[/,-]%d%c", &year, &month, &date, &c);
657 	switch (i) {
658 	case 4:
659 		/*
660 		 * If the character was sscanf()ed, then there's more
661 		 * stuff than we need.
662 		 */
663 		errx(1, "date specifier %s invalid", p);
664 	case 0:
665 		/*
666 		 * Not a form we can sscanf(), so void these, and we
667 		 * can try matching "country" names later.
668 		 */
669 		year = month = date = -1;
670 		break;
671 	case 1:
672 		month = 0;
673 		/*FALLTHROUGH*/
674 	case 2:
675 		date = 0;
676 		/*FALLTHROUGH*/
677 	    case 3:
678 		/*
679 		 * At last, some sanity checking on the values we were
680 		 * given.
681 		 */
682 		if (year < 1 || year > 9999)
683 			errx(1, "%d: illegal year value: use 1-9999", year);
684 		if (i > 1 && (month < 1 || month > 12))
685 			errx(1, "%d: illegal month value: use 1-12", month);
686 		if ((i == 3 && date < 1) || date < 0 ||
687 		    date > days_in_month[1][month])
688 			/*
689 			 * What about someone specifying a leap day in
690 			 * a non-leap year?  Well...that's a tricky
691 			 * one.  We can't yet *say* whether the year
692 			 * in question is a leap year.  What if the
693 			 * date given was, for example, 1700/2/29?  is
694 			 * that a valid leap day?
695 			 *
696 			 * So...we punt, and hope that saying 29 in
697 			 * the case of February isn't too bad an idea.
698 			 */
699 			errx(1, "%d: illegal date value: use 1-%d", date,
700 			     days_in_month[1][month]);
701 		break;
702 	}
703 
704 	/*
705 	 * A complete date was specified, so use the other pope.
706 	 */
707 	if (date > 0) {
708 		static struct reform Goestheveezl;
709 
710 		reform = &Goestheveezl;
711 		reform->country = "Bompzidaize";
712 		reform->year = year;
713 		reform->month = month;
714 		reform->date = date;
715 	}
716 
717 	/*
718 	 * No date information was specified, so let's try to match on
719 	 * country name.
720 	 */
721 	else if (year == -1) {
722 		for (reform = &reforms[0]; reform->year; reform++) {
723 			if (strcasecmp(p, reform->country) == 0)
724 				break;
725 		}
726 	}
727 
728 	/*
729 	 * We have *some* date information, but not a complete date.
730 	 * Let's see if we have enough to pick a single entry from the
731 	 * list that's not ambiguous.
732 	 */
733 	else {
734 		for (reform = &reforms[0]; reform->year; reform++) {
735 			if ((year == 0 || year == reform->year) &&
736 			    (month == 0 || month == reform->month) &&
737 			    (date == 0 || month == reform->date))
738 				break;
739 		}
740 
741 		if (i <= reform->ambiguity)
742 			errx(1, "%s: ambiguous short reform date specification", p);
743 	}
744 
745 	/*
746 	 * Oops...we reached the end of the list.
747 	 */
748 	if (reform->year == 0)
749 		errx(1, "reform name %s invalid", p);
750 
751 	/*
752 	 *
753 	 */
754 	reform->missing_days =
755 		j_leap_days(reform->year, reform->month, reform->date) -
756 		g_leap_days(reform->year, reform->month, reform->date) -
757 		GREGORIAN_MAGIC;
758 
759 	reform->first_missing_day =
760 		(reform->year - 1) * 365 +
761 		day_in_year(reform->date, reform->month, reform->year) +
762 		date +
763 		j_leap_days(reform->year, reform->month, reform->date);
764 
765 	/*
766 	 * Once we know the day of the week of the first missing day,
767 	 * skip back to the first of the month's day of the week.
768 	 */
769 	diw = day_in_week(reform->date, reform->month, reform->year);
770 	diw = (diw + 8 - (reform->date % 7)) % 7;
771 	diy = day_in_year(1, reform->month, reform->year);
772 
773 	/*
774 	 * We might need all four of these (if you switch from Julian
775 	 * to Gregorian at some point after 9900, you get a gap of 73
776 	 * days, and that can affect four months), and it doesn't hurt
777 	 * all that much to precompute them, so there.
778 	 */
779 	date = 1;
780 	days = 0;
781 	for (i = 0; i < 4; i++)
782 		reform_day_array(reform->month + i, reform->year,
783 				 &days, &date, &diw, &diy,
784 				 shift_days[0][i],
785 				 shift_days[1][i]);
786 }
787 
788 /*
789  * reform_day_array --
790  *	Pre-calculates the given month's calendar (in both "standard"
791  *	and "julian day" representations) with respect for days
792  *	skipped during a reform period.
793  */
794 void
795 reform_day_array(int month, int year, int *done, int *date, int *diw, int *diy,
796 	int *scal, int *jcal)
797 {
798 	int mdays;
799 
800 	/*
801 	 * If the reform was in the month of october or later, then
802 	 * the month number from the caller could "overflow".
803 	 */
804 	if (month > 12) {
805 		month -= 12;
806 		year++;
807 	}
808 
809 	/*
810 	 * Erase months, and set crib number.  The crib number is used
811 	 * later to determine if the month to be displayed is here or
812 	 * should be built on the fly with the generic routine
813 	 */
814 	memmove(scal, empty, MAXDAYS * sizeof(int));
815 	scal[MAXDAYS] = month + year * 12;
816 	memmove(jcal, empty, MAXDAYS * sizeof(int));
817 	jcal[MAXDAYS] = month + year * 12;
818 
819 	/*
820 	 * It doesn't matter what the actual month is when figuring
821 	 * out if this is a leap year or not, just so long as February
822 	 * gets the right number of days in it.
823 	 */
824 	mdays = days_in_month[g_leap_year(year, 3, 1)][month];
825 
826 	/*
827 	 * Bounce back to the first "row" in the day array, and fill
828 	 * in any days that actually occur.
829 	 */
830 	for (*diw %= 7; (*date - *done) <= mdays; (*date)++, (*diy)++) {
831 		/*
832 		 * "date" doesn't get reset by the caller across calls
833 		 * to this routine, so we can actually tell that we're
834 		 * looking at April the 41st.  Much easier than trying
835 		 * to calculate the absolute julian day for a given
836 		 * date and then checking that.
837 		 */
838 		if (*date < reform->date ||
839 		    *date >= reform->date + reform->missing_days) {
840 			scal[*diw] = *date - *done;
841 			jcal[*diw] = *diy;
842 			(*diw)++;
843 		}
844 	}
845 	*done += mdays;
846 }
847 
848 int
849 getnum(const char *p)
850 {
851 	long result;
852 	char *ep;
853 
854 	errno = 0;
855 	result = strtoul(p, &ep, 10);
856 	if (p[0] == '\0' || *ep != '\0')
857 		goto error;
858 	if (errno == ERANGE && result == ULONG_MAX)
859 		goto error;
860 	if (result > INT_MAX)
861 		goto error;
862 
863 	return (int)result;
864 
865 error:
866 	errx(1, "bad number: %s", p);
867 	/*NOTREACHED*/
868 }
869 
870 void
871 init_hilite(void)
872 {
873 	static char control[128];
874 	char cap[1024];
875 	char *tc;
876 
877 	hilite++;
878 
879 	if (!isatty(fileno(stdout)))
880 		return;
881 
882 	tc = getenv("TERM");
883 	if (tc == NULL)
884 		tc = "dumb";
885 	if (tgetent(&cap[0], tc) != 1)
886 		return;
887 
888 	tc = &control[0];
889 	if ((md = tgetstr(hilite > 1 ? "mr" : "md", &tc)))
890 		*tc++ = '\0';
891 	if ((me = tgetstr("me", &tc)))
892 		*tc++ = '\0';
893 	if (me == NULL || md == NULL)
894 		md = me = NULL;
895 }
896 
897 void
898 usage(void)
899 {
900 
901 	(void)fprintf(stderr,
902 	    "usage: cal [-hjry3] [-d day-of-week] [-B before] [-A after] "
903 	    "[-R reform-spec]\n           [[month] year]\n");
904 	exit(1);
905 }
906