xref: /minix/usr.bin/cal/cal.c (revision 0a6a1f1d)
1 /*	$NetBSD: cal.c,v 1.29 2015/06/16 22:54:10 christos 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\
38  The Regents of the University of California.  All rights reserved.");
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 1.29 2015/06/16 22:54:10 christos 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 <term.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 static 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 static int shift_days[2][4][MAXDAYS + 1];
85 
86 static const char *month_names[12] = {
87 	"January", "February", "March", "April", "May", "June",
88 	"July", "August", "September", "October", "November", "December",
89 };
90 
91 static const char *day_headings = " S  M Tu  W Th  F  S";
92 static const 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 static 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, 0, 0 },
167 	{ "Italy",		1, 1582, 10,  5, 0, 0 },
168 	{ "Spain",		1, 1582, 10,  5, 0, 0 },
169 	{ "Portugal",		1, 1582, 10,  5, 0, 0 },
170 	{ "Poland",		1, 1582, 10,  5, 0, 0 },
171 	{ "France",		2, 1582, 12, 10, 0, 0 },
172 	{ "Luxembourg",		2, 1582, 12, 22, 0, 0 },
173 	{ "Netherlands",	2, 1582, 12, 22, 0, 0 },
174 	{ "Bavaria",		0, 1583, 10,  6, 0, 0 },
175 	{ "Austria",		2, 1584,  1,  7, 0, 0 },
176 	{ "Switzerland",	2, 1584,  1, 12, 0, 0 },
177 	{ "Hungary",		0, 1587, 10, 22, 0, 0 },
178 	{ "Germany",		0, 1700,  2, 19, 0, 0 },
179 	{ "Norway",		0, 1700,  2, 19, 0, 0 },
180 	{ "Denmark",		0, 1700,  2, 19, 0, 0 },
181 	{ "Great Britain",	0, 1752,  9,  3, 0, 0 },
182 	{ "England",		0, 1752,  9,  3, 0, 0 },
183 	{ "America",		0, 1752,  9,  3, 0, 0 },
184 	{ "Sweden",		0, 1753,  2, 18, 0, 0 },
185 	{ "Finland",		0, 1753,  2, 18, 0, 0 },
186 	{ "Japan",		0, 1872, 12, 20, 0, 0 },
187 	{ "China",		0, 1911, 11,  7, 0, 0 },
188 	{ "Bulgaria",		0, 1916,  4,  1, 0, 0 },
189 	{ "U.S.S.R.",		0, 1918,  2,  1, 0, 0 },
190 	{ "Serbia",		0, 1919,  1, 19, 0, 0 },
191 	{ "Romania",		0, 1919,  1, 19, 0, 0 },
192 	{ "Greece",		0, 1924,  3, 10, 0, 0 },
193 	{ "Turkey",		0, 1925, 12, 19, 0, 0 },
194 	{ "Egypt",		0, 1928,  9, 18, 0, 0 },
195 	{ NULL,			0,    0,  0,  0, 0, 0 },
196 };
197 
198 static int julian;
199 static int dow;
200 static int hilite;
201 static const char *md, *me;
202 
203 static void	init_hilite(void);
204 static int	getnum(const char *);
205 static void	gregorian_reform(const char *);
206 static void	reform_day_array(int, int, int *, int *, int *,int *,int *,int *);
207 static int	ascii_day(char *, int);
208 static void	center(const char *, int, int);
209 static void	day_array(int, int, int *);
210 static int	day_in_week(int, int, int);
211 static int	day_in_year(int, int, int);
212 static void	monthrange(int, int, int, int, int);
213 static void	trim_trailing_spaces(char *);
214 __dead static void	usage(void);
215 
216 int
main(int argc,char ** argv)217 main(int argc, char **argv)
218 {
219 	struct tm *local_time;
220 	time_t now;
221 	int ch, yflag;
222 	long month, year;
223 	int before, after, use_reform;
224 	int yearly = 0;
225 	char *when, *eoi;
226 
227 	before = after = 0;
228 	use_reform = yflag = year = 0;
229 	when = NULL;
230 	while ((ch = getopt(argc, argv, "A:B:C:d:hjR:ry3")) != -1) {
231 		switch (ch) {
232 		case 'A':
233 			after = getnum(optarg);
234 			if (after < 0)
235 				errx(1, "Argument to -A must be positive");
236 			break;
237 		case 'B':
238 			before = getnum(optarg);
239 			if (before < 0)
240 				errx(1, "Argument to -B must be positive");
241 			break;
242 		case 'C':
243 			after = before = getnum(optarg);
244 			if (after < 0)
245 				errx(1, "Argument to -C must be positive");
246 			break;
247 		case 'd':
248 			dow = getnum(optarg);
249 			if (dow < 0 || dow > 6)
250 				errx(1, "illegal day of week value: use 0-6");
251 			break;
252 		case 'h':
253 			init_hilite();
254 			break;
255 		case 'j':
256 			julian = 1;
257 			break;
258 		case 'R':
259 			when = optarg;
260 			break;
261 		case 'r':
262 			use_reform = 1;
263 			break;
264 		case 'y':
265 			yflag = 1;
266 			break;
267 		case '3':
268 			before = after = 1;
269 			break;
270 		case '?':
271 		default:
272 			usage();
273 			/* NOTREACHED */
274 		}
275 	}
276 
277 	argc -= optind;
278 	argv += optind;
279 
280 	if (when != NULL)
281 		gregorian_reform(when);
282 	if (reform == NULL)
283 		gregorian_reform("DEFAULT");
284 
285 	month = 0;
286 	switch (argc) {
287 	case 2:
288 		month = strtol(*argv++, &eoi, 10);
289 		if (month < 1 || month > 12 || *eoi != '\0')
290 			errx(1, "illegal month value: use 1-12");
291 		year = strtol(*argv, &eoi, 10);
292 		if (year < 1 || year > 9999 || *eoi != '\0')
293 			errx(1, "illegal year value: use 1-9999");
294 		break;
295 	case 1:
296 		year = strtol(*argv, &eoi, 10);
297 		if (year < 1 || year > 9999 || (*eoi != '\0' && *eoi != '/' && *eoi != '-'))
298 			errx(1, "illegal year value: use 1-9999");
299 		if (*eoi != '\0') {
300 			month = strtol(eoi + 1, &eoi, 10);
301 			if (month < 1 || month > 12 || *eoi != '\0')
302 				errx(1, "illegal month value: use 1-12");
303 		}
304 		break;
305 	case 0:
306 		(void)time(&now);
307 		local_time = localtime(&now);
308 		if (use_reform)
309 			year = reform->year;
310 		else
311 			year = local_time->tm_year + TM_YEAR_BASE;
312 		if (!yflag) {
313 			if (use_reform)
314 				month = reform->month;
315 			else
316 				month = local_time->tm_mon + 1;
317 		}
318 		break;
319 	default:
320 		usage();
321 	}
322 
323 	if (!month) {
324 		/* yearly */
325 		month = 1;
326 		before = 0;
327 		after = 11;
328 		yearly = 1;
329 	}
330 
331 	monthrange(month, year, before, after, yearly);
332 
333 	exit(0);
334 }
335 
336 #define	DAY_LEN		3		/* 3 spaces per day */
337 #define	J_DAY_LEN	4		/* 4 spaces per day */
338 #define	WEEK_LEN	20		/* 7 * 3 - one space at the end */
339 #define	J_WEEK_LEN	27		/* 7 * 4 - one space at the end */
340 #define	HEAD_SEP	2		/* spaces between day headings */
341 #define	J_HEAD_SEP	2
342 #define	MONTH_PER_ROW	3		/* how many monthes in a row */
343 #define	J_MONTH_PER_ROW	2
344 
345 static void
monthrange(int month,int year,int before,int after,int yearly)346 monthrange(int month, int year, int before, int after, int yearly)
347 {
348 	int startmonth, startyear;
349 	int endmonth, endyear;
350 	int i, row;
351 	int days[3][MAXDAYS];
352 	char lineout[256];
353 	int inayear;
354 	int newyear;
355 	int day_len, week_len, head_sep;
356 	int month_per_row;
357 	int skip, r_off, w_off;
358 
359 	if (julian) {
360 		day_len = J_DAY_LEN;
361 		week_len = J_WEEK_LEN;
362 		head_sep = J_HEAD_SEP;
363 		month_per_row = J_MONTH_PER_ROW;
364 	}
365 	else {
366 		day_len = DAY_LEN;
367 		week_len = WEEK_LEN;
368 		head_sep = HEAD_SEP;
369 		month_per_row = MONTH_PER_ROW;
370 	}
371 
372 	month--;
373 
374 	startyear = year - (before + 12 - 1 - month) / 12;
375 	startmonth = 12 - 1 - ((before + 12 - 1 - month) % 12);
376 	endyear = year + (month + after) / 12;
377 	endmonth = (month + after) % 12;
378 
379 	if (startyear < 0 || endyear > 9999) {
380 		errx(1, "year should be in 1-9999");
381 	}
382 
383 	year = startyear;
384 	month = startmonth;
385 	inayear = newyear = (year != endyear || yearly);
386 	if (inayear) {
387 		skip = month % month_per_row;
388 		month -= skip;
389 	}
390 	else {
391 		skip = 0;
392 	}
393 
394 	do {
395 		if (newyear) {
396 			(void)snprintf(lineout, sizeof(lineout), "%d", year);
397 			center(lineout, week_len * month_per_row +
398 			    head_sep * (month_per_row - 1), 0);
399 			(void)printf("\n\n");
400 			newyear = 0;
401 		}
402 
403 		for (i = 0; i < skip; i++)
404 			center("", week_len, head_sep);
405 
406 		for (; i < month_per_row; i++) {
407 			int sep;
408 
409 			if (year == endyear && month + i > endmonth)
410 				break;
411 
412 			sep = (i == month_per_row - 1) ? 0 : head_sep;
413 			day_array(month + i + 1, year, days[i]);
414 			if (inayear) {
415 				center(month_names[month + i], week_len, sep);
416 			}
417 			else {
418 				snprintf(lineout, sizeof(lineout), "%s %d",
419 				    month_names[month + i], year);
420 				center(lineout, week_len, sep);
421 			}
422 		}
423 		printf("\n");
424 
425 		for (i = 0; i < skip; i++)
426 			center("", week_len, head_sep);
427 
428 		for (; i < month_per_row; i++) {
429 			int sep;
430 
431 			if (year == endyear && month + i > endmonth)
432 				break;
433 
434 			sep = (i == month_per_row - 1) ? 0 : head_sep;
435 			if (dow) {
436 				printf("%s ", (julian) ?
437 				    j_day_headings + 4 * dow :
438 				    day_headings + 3 * dow);
439 				printf("%.*s", dow * (julian ? 4 : 3) - 1,
440 				       (julian) ? j_day_headings : day_headings);
441 			} else
442 				printf("%s", (julian) ? j_day_headings : day_headings);
443 			printf("%*s", sep, "");
444 		}
445 		printf("\n");
446 
447 		for (row = 0; row < 6; row++) {
448 			char *p = NULL;
449 
450 			memset(lineout, ' ', sizeof(lineout));
451 			for (i = 0; i < skip; i++) {
452 				/* nothing */
453 			}
454 			w_off = 0;
455 			for (; i < month_per_row; i++) {
456 				int col, *dp;
457 
458 				if (year == endyear && month + i > endmonth)
459 					break;
460 
461 				p = lineout + i * (week_len + 2) + w_off;
462 				dp = &days[i][row * 7];
463 				for (col = 0; col < 7;
464 				     col++, p += day_len + r_off) {
465 					r_off = ascii_day(p, *dp++);
466 					w_off += r_off;
467 				}
468 			}
469 			*p = '\0';
470 			trim_trailing_spaces(lineout);
471 			(void)printf("%s\n", lineout);
472 		}
473 
474 		skip = 0;
475 		month += month_per_row;
476 		if (month >= 12) {
477 			month -= 12;
478 			year++;
479 			newyear = 1;
480 		}
481 	} while (year < endyear || (year == endyear && month <= endmonth));
482 }
483 
484 /*
485  * day_array --
486  *	Fill in an array of 42 integers with a calendar.  Assume for a moment
487  *	that you took the (maximum) 6 rows in a calendar and stretched them
488  *	out end to end.  You would have 42 numbers or spaces.  This routine
489  *	builds that array for any month from Jan. 1 through Dec. 9999.
490  */
491 static void
day_array(int month,int year,int * days)492 day_array(int month, int year, int *days)
493 {
494 	int day, dw, dm;
495 	time_t t;
496 	struct tm *tm;
497 
498 	t = time(NULL);
499 	tm = localtime(&t);
500 	tm->tm_year += TM_YEAR_BASE;
501 	tm->tm_mon++;
502 	tm->tm_yday++; /* jan 1 is 1 for us, not 0 */
503 
504 	for (dm = month + year * 12, dw = 0; dw < 4; dw++) {
505 		if (dm == shift_days[julian][dw][MAXDAYS]) {
506 			memmove(days, shift_days[julian][dw],
507 				MAXDAYS * sizeof(int));
508 			return;
509 		}
510 	}
511 
512 	memmove(days, empty, MAXDAYS * sizeof(int));
513 	dm = days_in_month[leap_year(year)][month];
514 	dw = day_in_week(1, month, year);
515 	day = julian ? day_in_year(1, month, year) : 1;
516 	while (dm--) {
517 		if (hilite && year == tm->tm_year &&
518 		    (julian ? (day == tm->tm_yday) :
519 		     (month == tm->tm_mon && day == tm->tm_mday)))
520 			days[dw++] = SPACE - day++;
521 		else
522 			days[dw++] = day++;
523 	}
524 }
525 
526 /*
527  * day_in_year --
528  *	return the 1 based day number within the year
529  */
530 static int
day_in_year(int day,int month,int year)531 day_in_year(int day, int month, int year)
532 {
533 	int i, leap;
534 
535 	leap = leap_year(year);
536 	for (i = 1; i < month; i++)
537 		day += days_in_month[leap][i];
538 	return (day);
539 }
540 
541 /*
542  * day_in_week
543  *	return the 0 based day number for any date from 1 Jan. 1 to
544  *	31 Dec. 9999.  Returns the day of the week of the first
545  *	missing day for any given Gregorian shift.
546  */
547 static int
day_in_week(int day,int month,int year)548 day_in_week(int day, int month, int year)
549 {
550 	long temp;
551 
552 	temp = (long)(year - 1) * 365 + leap_years_since_year_1(year - 1)
553 	    + day_in_year(day, month, year);
554 	if (temp < FIRST_MISSING_DAY)
555 		return ((temp - dow + 6 + SATURDAY) % 7);
556 	if (temp >= (FIRST_MISSING_DAY + NUMBER_MISSING_DAYS))
557 		return (((temp - dow + 6 + SATURDAY) - NUMBER_MISSING_DAYS) % 7);
558 	return ((FIRST_MISSING_DAY - dow + 6 + SATURDAY) % 7);
559 }
560 
561 static int
ascii_day(char * p,int day)562 ascii_day(char *p, int day)
563 {
564 	int display, val, rc;
565 	char *b;
566 	static const char *aday[] = {
567 		"",
568 		" 1", " 2", " 3", " 4", " 5", " 6", " 7",
569 		" 8", " 9", "10", "11", "12", "13", "14",
570 		"15", "16", "17", "18", "19", "20", "21",
571 		"22", "23", "24", "25", "26", "27", "28",
572 		"29", "30", "31",
573 	};
574 
575 	if (day == SPACE) {
576 		memset(p, ' ', julian ? J_DAY_LEN : DAY_LEN);
577 		return (0);
578 	}
579 	if (day < SPACE) {
580 		b = p;
581 		day = SPACE - day;
582 	} else
583 		b = NULL;
584 	if (julian) {
585 		if ((val = day / 100) != 0) {
586 			day %= 100;
587 			*p++ = val + '0';
588 			display = 1;
589 		} else {
590 			*p++ = ' ';
591 			display = 0;
592 		}
593 		val = day / 10;
594 		if (val || display)
595 			*p++ = val + '0';
596 		else
597 			*p++ = ' ';
598 		*p++ = day % 10 + '0';
599 	} else {
600 		*p++ = aday[day][0];
601 		*p++ = aday[day][1];
602 	}
603 
604 	rc = 0;
605 	if (b != NULL) {
606 		const char *t;
607 		char h[64];
608 		int l;
609 
610 		l = p - b;
611 		memcpy(h, b, l);
612 		p = b;
613 
614 		if (md != NULL) {
615 			for (t = md; *t; rc++)
616 				*p++ = *t++;
617 			memcpy(p, h, l);
618 			p += l;
619 			for (t = me; *t; rc++)
620 				*p++ = *t++;
621 		} else {
622 			for (t = &h[0]; l--; t++) {
623 				*p++ = *t;
624 				rc++;
625 				*p++ = '\b';
626 				rc++;
627 				*p++ = *t;
628 			}
629 		}
630 	}
631 
632 	*p = ' ';
633 	return (rc);
634 }
635 
636 static void
trim_trailing_spaces(char * s)637 trim_trailing_spaces(char *s)
638 {
639 	char *p;
640 
641 	for (p = s; *p; ++p)
642 		continue;
643 	while (p > s && isspace((unsigned char)*--p))
644 		continue;
645 	if (p > s)
646 		++p;
647 	*p = '\0';
648 }
649 
650 static void
center(const char * str,int len,int separate)651 center(const char *str, int len, int separate)
652 {
653 
654 	len -= strlen(str);
655 	(void)printf("%*s%s%*s", len / 2, "", str, len / 2 + len % 2, "");
656 	if (separate)
657 		(void)printf("%*s", separate, "");
658 }
659 
660 /*
661  * gregorian_reform --
662  *	Given a description of date on which the Gregorian Reform was
663  *	applied.  The argument can be any of the "country" names
664  *	listed in the reforms array (case insensitive) or a date of
665  *	the form YYYY/MM/DD.  The date and month can be omitted if
666  *	doing so would not select more than one different built-in
667  *	reform point.
668  */
669 static void
gregorian_reform(const char * p)670 gregorian_reform(const char *p)
671 {
672 	int year, month, date;
673 	int i, days, diw, diy;
674 	char c;
675 
676 	i = sscanf(p, "%d%*[/,-]%d%*[/,-]%d%c", &year, &month, &date, &c);
677 	switch (i) {
678 	case 4:
679 		/*
680 		 * If the character was sscanf()ed, then there's more
681 		 * stuff than we need.
682 		 */
683 		errx(1, "date specifier %s invalid", p);
684 	case 0:
685 		/*
686 		 * Not a form we can sscanf(), so void these, and we
687 		 * can try matching "country" names later.
688 		 */
689 		year = month = date = -1;
690 		break;
691 	case 1:
692 		month = 0;
693 		/*FALLTHROUGH*/
694 	case 2:
695 		date = 0;
696 		/*FALLTHROUGH*/
697 	    case 3:
698 		/*
699 		 * At last, some sanity checking on the values we were
700 		 * given.
701 		 */
702 		if (year < 1 || year > 9999)
703 			errx(1, "%d: illegal year value: use 1-9999", year);
704 		if (i > 1 && (month < 1 || month > 12))
705 			errx(1, "%d: illegal month value: use 1-12", month);
706 		if ((i == 3 && date < 1) || date < 0 ||
707 		    date > days_in_month[1][month])
708 			/*
709 			 * What about someone specifying a leap day in
710 			 * a non-leap year?  Well...that's a tricky
711 			 * one.  We can't yet *say* whether the year
712 			 * in question is a leap year.  What if the
713 			 * date given was, for example, 1700/2/29?  is
714 			 * that a valid leap day?
715 			 *
716 			 * So...we punt, and hope that saying 29 in
717 			 * the case of February isn't too bad an idea.
718 			 */
719 			errx(1, "%d: illegal date value: use 1-%d", date,
720 			     days_in_month[1][month]);
721 		break;
722 	}
723 
724 	/*
725 	 * A complete date was specified, so use the other pope.
726 	 */
727 	if (date > 0) {
728 		static struct reform Goestheveezl;
729 
730 		reform = &Goestheveezl;
731 		reform->country = "Bompzidaize";
732 		reform->year = year;
733 		reform->month = month;
734 		reform->date = date;
735 	}
736 
737 	/*
738 	 * No date information was specified, so let's try to match on
739 	 * country name.
740 	 */
741 	else if (year == -1) {
742 		for (reform = &reforms[0]; reform->year; reform++) {
743 			if (strcasecmp(p, reform->country) == 0)
744 				break;
745 		}
746 	}
747 
748 	/*
749 	 * We have *some* date information, but not a complete date.
750 	 * Let's see if we have enough to pick a single entry from the
751 	 * list that's not ambiguous.
752 	 */
753 	else {
754 		for (reform = &reforms[0]; reform->year; reform++) {
755 			if ((year == 0 || year == reform->year) &&
756 			    (month == 0 || month == reform->month) &&
757 			    (date == 0 || month == reform->date))
758 				break;
759 		}
760 
761 		if (i <= reform->ambiguity)
762 			errx(1, "%s: ambiguous short reform date specification", p);
763 	}
764 
765 	/*
766 	 * Oops...we reached the end of the list.
767 	 */
768 	if (reform->year == 0)
769 		errx(1, "reform name %s invalid", p);
770 
771 	/*
772 	 *
773 	 */
774 	reform->missing_days =
775 		j_leap_days(reform->year, reform->month, reform->date) -
776 		g_leap_days(reform->year, reform->month, reform->date) -
777 		GREGORIAN_MAGIC;
778 
779 	reform->first_missing_day =
780 		(reform->year - 1) * 365 +
781 		day_in_year(reform->date, reform->month, reform->year) +
782 		date +
783 		j_leap_days(reform->year, reform->month, reform->date);
784 
785 	/*
786 	 * Once we know the day of the week of the first missing day,
787 	 * skip back to the first of the month's day of the week.
788 	 */
789 	diw = day_in_week(reform->date, reform->month, reform->year);
790 	diw = (diw + 8 - (reform->date % 7)) % 7;
791 	diy = day_in_year(1, reform->month, reform->year);
792 
793 	/*
794 	 * We might need all four of these (if you switch from Julian
795 	 * to Gregorian at some point after 9900, you get a gap of 73
796 	 * days, and that can affect four months), and it doesn't hurt
797 	 * all that much to precompute them, so there.
798 	 */
799 	date = 1;
800 	days = 0;
801 	for (i = 0; i < 4; i++)
802 		reform_day_array(reform->month + i, reform->year,
803 				 &days, &date, &diw, &diy,
804 				 shift_days[0][i],
805 				 shift_days[1][i]);
806 }
807 
808 /*
809  * reform_day_array --
810  *	Pre-calculates the given month's calendar (in both "standard"
811  *	and "julian day" representations) with respect for days
812  *	skipped during a reform period.
813  */
814 static void
reform_day_array(int month,int year,int * done,int * date,int * diw,int * diy,int * scal,int * jcal)815 reform_day_array(int month, int year, int *done, int *date, int *diw, int *diy,
816 	int *scal, int *jcal)
817 {
818 	int mdays;
819 
820 	/*
821 	 * If the reform was in the month of october or later, then
822 	 * the month number from the caller could "overflow".
823 	 */
824 	if (month > 12) {
825 		month -= 12;
826 		year++;
827 	}
828 
829 	/*
830 	 * Erase months, and set crib number.  The crib number is used
831 	 * later to determine if the month to be displayed is here or
832 	 * should be built on the fly with the generic routine
833 	 */
834 	memmove(scal, empty, MAXDAYS * sizeof(int));
835 	scal[MAXDAYS] = month + year * 12;
836 	memmove(jcal, empty, MAXDAYS * sizeof(int));
837 	jcal[MAXDAYS] = month + year * 12;
838 
839 	/*
840 	 * It doesn't matter what the actual month is when figuring
841 	 * out if this is a leap year or not, just so long as February
842 	 * gets the right number of days in it.
843 	 */
844 	mdays = days_in_month[g_leap_year(year, 3, 1)][month];
845 
846 	/*
847 	 * Bounce back to the first "row" in the day array, and fill
848 	 * in any days that actually occur.
849 	 */
850 	for (*diw %= 7; (*date - *done) <= mdays; (*date)++, (*diy)++) {
851 		/*
852 		 * "date" doesn't get reset by the caller across calls
853 		 * to this routine, so we can actually tell that we're
854 		 * looking at April the 41st.  Much easier than trying
855 		 * to calculate the absolute julian day for a given
856 		 * date and then checking that.
857 		 */
858 		if (*date < reform->date ||
859 		    *date >= reform->date + reform->missing_days) {
860 			scal[*diw] = *date - *done;
861 			jcal[*diw] = *diy;
862 			(*diw)++;
863 		}
864 	}
865 	*done += mdays;
866 }
867 
868 static int
getnum(const char * p)869 getnum(const char *p)
870 {
871 	unsigned long result;
872 	char *ep;
873 
874 	errno = 0;
875 	result = strtoul(p, &ep, 10);
876 	if (p[0] == '\0' || *ep != '\0')
877 		goto error;
878 	if (errno == ERANGE && result == ULONG_MAX)
879 		goto error;
880 	if (result > INT_MAX)
881 		goto error;
882 
883 	return (int)result;
884 
885 error:
886 	errx(1, "bad number: %s", p);
887 	/*NOTREACHED*/
888 }
889 
890 static void
init_hilite(void)891 init_hilite(void)
892 {
893 	const char *term;
894 	int errret;
895 
896 	hilite++;
897 
898 	if (!isatty(fileno(stdout)))
899 		return;
900 
901 	term = getenv("TERM");
902 	if (term == NULL)
903 		term = "dumb";
904 	if (setupterm(term, fileno(stdout), &errret) != 0 && errret != 1)
905 		return;
906 
907 	if (hilite > 1)
908 		md = enter_reverse_mode;
909 	else
910 		md = enter_bold_mode;
911 	me = exit_attribute_mode;
912 	if (me == NULL || md == NULL)
913 		md = me = NULL;
914 }
915 
916 static void
usage(void)917 usage(void)
918 {
919 
920 	(void)fprintf(stderr,
921 	    "usage: cal [-3hjry] [-A after] [-B before] [-C context] [-d day-of-week] "
922 	    "[-R reform-spec]\n           [[month] year]\n");
923 	exit(1);
924 }
925