xref: /freebsd/usr.bin/ncal/ncal.c (revision 6580f5c38dd5b01aeeaed16b370f1a12423437f0)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 1997 Wolfgang Helbig
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 
29 #include <sys/cdefs.h>
30 #include <calendar.h>
31 #include <ctype.h>
32 #include <err.h>
33 #include <langinfo.h>
34 #include <libgen.h>
35 #include <locale.h>
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <string.h>
39 #include <sysexits.h>
40 #include <time.h>
41 #include <unistd.h>
42 #include <wchar.h>
43 #include <wctype.h>
44 #include <term.h>
45 #undef lines			/* term.h defines this */
46 
47 /* Width of one month with backward compatibility and in regular mode*/
48 #define MONTH_WIDTH_B_J 27
49 #define MONTH_WIDTH_B 20
50 
51 #define MONTH_WIDTH_R_J 24
52 #define MONTH_WIDTH_R 18
53 
54 #define MAX_WIDTH 64
55 
56 typedef struct date date;
57 
58 struct monthlines {
59 	wchar_t name[MAX_WIDTH + 1];
60 	char lines[7][MAX_WIDTH + 1];
61 	char weeks[MAX_WIDTH + 1];
62 	unsigned int extralen[7];
63 };
64 
65 struct weekdays {
66 	wchar_t names[7][4];
67 };
68 
69 /* The switches from Julian to Gregorian in some countries */
70 static struct djswitch {
71 	const char *cc;	/* Country code according to ISO 3166 */
72 	const char *nm;	/* Name of country */
73 	date dt;	/* Last day of Julian calendar */
74 } switches[] = {
75 	{"AL", "Albania",       {1912, 11, 30}},
76 	{"AT", "Austria",       {1583, 10,  5}},
77 	{"AU", "Australia",     {1752,  9,  2}},
78 	{"BE", "Belgium",       {1582, 12, 14}},
79 	{"BG", "Bulgaria",      {1916,  3, 31}},
80 	{"CA", "Canada",        {1752,  9,  2}},
81 	{"CH", "Switzerland",   {1655,  2, 28}},
82 	{"CN", "China",         {1911, 12, 18}},
83 	{"CZ", "Czech Republic",{1584,  1,  6}},
84 	{"DE", "Germany",       {1700,  2, 18}},
85 	{"DK", "Denmark",       {1700,  2, 18}},
86 	{"ES", "Spain",         {1582, 10,  4}},
87 	{"FI", "Finland",       {1753,  2, 17}},
88 	{"FR", "France",        {1582, 12,  9}},
89 	{"GB", "United Kingdom",{1752,  9,  2}},
90 	{"GR", "Greece",        {1924,  3,  9}},
91 	{"HU", "Hungary",       {1587, 10, 21}},
92 	{"IS", "Iceland",       {1700, 11, 16}},
93 	{"IT", "Italy",         {1582, 10,  4}},
94 	{"JP", "Japan",         {1918, 12, 18}},
95 	{"LT", "Lithuania",     {1918,  2,  1}},
96 	{"LU", "Luxembourg",    {1582, 12, 14}},
97 	{"LV", "Latvia",        {1918,  2,  1}},
98 	{"NL", "Netherlands",   {1582, 12, 14}},
99 	{"NO", "Norway",        {1700,  2, 18}},
100 	{"PL", "Poland",        {1582, 10,  4}},
101 	{"PT", "Portugal",      {1582, 10,  4}},
102 	{"RO", "Romania",       {1919,  3, 31}},
103 	{"RU", "Russia",        {1918,  1, 31}},
104 	{"SI", "Slovenia",      {1919,  3,  4}},
105 	{"SE", "Sweden",        {1753,  2, 17}},
106 	{"TR", "Turkey",        {1926, 12, 18}},
107 	{"US", "United States", {1752,  9,  2}},
108 	{"YU", "Yugoslavia",    {1919,  3,  4}}
109 };
110 
111 static struct djswitch *dftswitch =
112     switches + sizeof(switches) / sizeof(struct djswitch) - 2;
113     /* default switch (should be "US") */
114 
115 /* Table used to print day of month and week numbers */
116 static char daystr[] = "     1  2  3  4  5  6  7  8  9 10 11 12 13 14 15"
117 		       " 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31"
118 		       " 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47"
119 		       " 48 49 50 51 52 53";
120 
121 /* Table used to print day of year and week numbers */
122 static char jdaystr[] = "       1   2   3   4   5   6   7   8   9"
123 			"  10  11  12  13  14  15  16  17  18  19"
124 			"  20  21  22  23  24  25  26  27  28  29"
125 			"  30  31  32  33  34  35  36  37  38  39"
126 			"  40  41  42  43  44  45  46  47  48  49"
127 			"  50  51  52  53  54  55  56  57  58  59"
128 			"  60  61  62  63  64  65  66  67  68  69"
129 			"  70  71  72  73  74  75  76  77  78  79"
130 			"  80  81  82  83  84  85  86  87  88  89"
131 			"  90  91  92  93  94  95  96  97  98  99"
132 			" 100 101 102 103 104 105 106 107 108 109"
133 			" 110 111 112 113 114 115 116 117 118 119"
134 			" 120 121 122 123 124 125 126 127 128 129"
135 			" 130 131 132 133 134 135 136 137 138 139"
136 			" 140 141 142 143 144 145 146 147 148 149"
137 			" 150 151 152 153 154 155 156 157 158 159"
138 			" 160 161 162 163 164 165 166 167 168 169"
139 			" 170 171 172 173 174 175 176 177 178 179"
140 			" 180 181 182 183 184 185 186 187 188 189"
141 			" 190 191 192 193 194 195 196 197 198 199"
142 			" 200 201 202 203 204 205 206 207 208 209"
143 			" 210 211 212 213 214 215 216 217 218 219"
144 			" 220 221 222 223 224 225 226 227 228 229"
145 			" 230 231 232 233 234 235 236 237 238 239"
146 			" 240 241 242 243 244 245 246 247 248 249"
147 			" 250 251 252 253 254 255 256 257 258 259"
148 			" 260 261 262 263 264 265 266 267 268 269"
149 			" 270 271 272 273 274 275 276 277 278 279"
150 			" 280 281 282 283 284 285 286 287 288 289"
151 			" 290 291 292 293 294 295 296 297 298 299"
152 			" 300 301 302 303 304 305 306 307 308 309"
153 			" 310 311 312 313 314 315 316 317 318 319"
154 			" 320 321 322 323 324 325 326 327 328 329"
155 			" 330 331 332 333 334 335 336 337 338 339"
156 			" 340 341 342 343 344 345 346 347 348 349"
157 			" 350 351 352 353 354 355 356 357 358 359"
158 			" 360 361 362 363 364 365 366";
159 
160 static int flag_nohighlight;	/* user doesn't want a highlighted today */
161 static int flag_weeks;		/* user wants number of week */
162 static int nswitch;		/* user defined switch date */
163 static int nswitchb;		/* switch date for backward compatibility */
164 static int highlightdate;
165 
166 static char	*center(char *s, char *t, int w);
167 static wchar_t *wcenter(wchar_t *s, wchar_t *t, int w);
168 static int	firstday(int y, int m);
169 static void	highlight(char *dst, char *src, int len, int *extraletters);
170 static void	mkmonthr(int year, int month, int jd_flag,
171     struct monthlines * monthl);
172 static void	mkmonthb(int year, int month, int jd_flag,
173     struct monthlines * monthl);
174 static void	mkweekdays(struct weekdays * wds);
175 static void	monthranger(int year, int m, int jd_flag,
176     int before, int after);
177 static void	monthrangeb(int year, int m, int jd_flag,
178     int before, int after);
179 static int	parsemonth(const char *s, int *m, int *y);
180 static void	printcc(void);
181 static void	printeaster(int year, int julian, int orthodox);
182 static date	*sdater(int ndays, struct date * d);
183 static date	*sdateb(int ndays, struct date * d);
184 static int	sndaysr(struct date * d);
185 static int	sndaysb(struct date * d);
186 static void	usage(void);
187 
188 int
189 main(int argc, char *argv[])
190 {
191 	struct  djswitch *p, *q;	/* to search user defined switch date */
192 	date	never = {10000, 1, 1};	/* outside valid range of dates */
193 	date	ukswitch = {1752, 9, 2};/* switch date for Great Britain */
194 	date	dt;
195 	int     ch;			/* holds the option character */
196 	int     m = 0;			/* month */
197 	int	y = 0;			/* year */
198 	int     flag_backward = 0;	/* user called cal--backward compat. */
199 	int     flag_wholeyear = 0;	/* user wants the whole year */
200 	int	flag_julian_cal = 0;	/* user wants Julian Calendar */
201 	int     flag_julian_day = 0;	/* user wants the Julian day numbers */
202 	int	flag_orthodox = 0;	/* user wants Orthodox easter */
203 	int	flag_easter = 0;	/* user wants easter date */
204 	int	flag_3months = 0;	/* user wants 3 month display (-3) */
205 	int	flag_after = 0;		/* user wants to see months after */
206 	int	flag_before = 0;	/* user wants to see months before */
207 	int	flag_specifiedmonth = 0;/* user wants to see this month (-m) */
208 	int	flag_givenmonth = 0;	/* user has specified month [n] */
209 	int	flag_givenyear = 0;	/* user has specified year [n] */
210 	char	*cp;			/* character pointer */
211 	char	*flag_today = NULL;	/* debug: use date as being today */
212 	char	*flag_month = NULL;	/* requested month as string */
213 	char	*flag_highlightdate = NULL; /* debug: date to highlight */
214 	int	before, after;
215 	const char    *locale;		/* locale to get country code */
216 
217 	flag_nohighlight = 0;
218 	flag_weeks = 0;
219 
220 	/*
221 	 * Use locale to determine the country code,
222 	 * and use the country code to determine the default
223 	 * switchdate and date format from the switches table.
224 	 */
225 	if (setlocale(LC_ALL, "") == NULL)
226 		warn("setlocale");
227 	locale = setlocale(LC_TIME, NULL);
228 	if (locale == NULL ||
229 	    strcmp(locale, "C") == 0 ||
230 	    strcmp(locale, "POSIX") == 0 ||
231 	    strcmp(locale, "ASCII") == 0 ||
232 	    strcmp(locale, "US-ASCII") == 0)
233 		locale = "_US";
234 	q = switches + sizeof(switches) / sizeof(struct djswitch);
235 	for (p = switches; p != q; p++)
236 		if ((cp = strstr(locale, p->cc)) != NULL && *(cp - 1) == '_')
237 			break;
238 	if (p == q) {
239 		nswitch = ndaysj(&dftswitch->dt);
240 	} else {
241 		nswitch = ndaysj(&p->dt);
242 		dftswitch = p;
243 	}
244 
245 
246 	/*
247 	 * Get the filename portion of argv[0] and set flag_backward if
248 	 * this program is called "cal".
249 	 */
250 	if (strncmp(basename(argv[0]), "cal", strlen("cal")) == 0)
251 		flag_backward = 1;
252 
253 	/* Set the switch date to United Kingdom if backwards compatible */
254 	if (flag_backward)
255 		nswitchb = ndaysj(&ukswitch);
256 
257 	before = after = -1;
258 
259 	while ((ch = getopt(argc, argv, "3A:B:Cd:eH:hjJm:Nops:wy")) != -1)
260 		switch (ch) {
261 		case '3':
262 			flag_3months = 1;
263 			break;
264 		case 'A':
265 			if (flag_after > 0)
266 				errx(EX_USAGE, "Double -A specified");
267 			flag_after = strtol(optarg, NULL, 10);
268 			if (flag_after <= 0)
269 				errx(EX_USAGE,
270 				    "Argument to -A must be positive");
271 			break;
272 		case 'B':
273 			if (flag_before > 0)
274 				errx(EX_USAGE, "Double -B specified");
275 			flag_before = strtol(optarg, NULL, 10);
276 			if (flag_before <= 0)
277 				errx(EX_USAGE,
278 				    "Argument to -B must be positive");
279 			break;
280 		case 'J':
281 			if (flag_backward)
282 				usage();
283 			nswitch = ndaysj(&never);
284 			flag_julian_cal = 1;
285 			break;
286 		case 'C':
287 			flag_backward = 1;
288 			break;
289 		case 'N':
290 			flag_backward = 0;
291 			break;
292 		case 'd':
293 			flag_today = optarg;
294 			break;
295 		case 'H':
296 			flag_highlightdate = optarg;
297 			break;
298 		case 'h':
299 			flag_nohighlight = 1;
300 			break;
301 		case 'e':
302 			if (flag_backward)
303 				usage();
304 			flag_easter = 1;
305 			break;
306 		case 'j':
307 			flag_julian_day = 1;
308 			break;
309 		case 'm':
310 			if (flag_specifiedmonth)
311 				errx(EX_USAGE, "Double -m specified");
312 			flag_month = optarg;
313 			flag_specifiedmonth = 1;
314 			break;
315 		case 'o':
316 			if (flag_backward)
317 				usage();
318 			flag_orthodox = 1;
319 			flag_easter = 1;
320 			break;
321 		case 'p':
322 			if (flag_backward)
323 				usage();
324 			printcc();
325 			return (0);
326 			break;
327 		case 's':
328 			if (flag_backward)
329 				usage();
330 			q = switches +
331 			    sizeof(switches) / sizeof(struct djswitch);
332 			for (p = switches;
333 			     p != q && strcmp(p->cc, optarg) != 0; p++)
334 				;
335 			if (p == q)
336 				errx(EX_USAGE,
337 				    "%s: invalid country code", optarg);
338 			nswitch = ndaysj(&(p->dt));
339 			break;
340 		case 'w':
341 			if (flag_backward)
342 				usage();
343 			flag_weeks = 1;
344 			break;
345 		case 'y':
346 			flag_wholeyear = 1;
347 			break;
348 		default:
349 			usage();
350 		}
351 
352 	argc -= optind;
353 	argv += optind;
354 
355 	switch (argc) {
356 	case 2:
357 		if (flag_easter)
358 			usage();
359 		flag_month = *argv++;
360 		flag_givenmonth = 1;
361 		m = strtol(flag_month, NULL, 10);
362 		/* FALLTHROUGH */
363 	case 1:
364 		y = atoi(*argv);
365 		if (y < 1 || y > 9999)
366 			errx(EX_USAGE, "year `%s' not in range 1..9999", *argv);
367 		argv++;
368 		flag_givenyear = 1;
369 		break;
370 	case 0:
371 		if (flag_today != NULL) {
372 			y = strtol(flag_today, NULL, 10);
373 			m = strtol(flag_today + 5, NULL, 10);
374 		} else {
375 			time_t t;
376 			struct tm *tm;
377 
378 			t = time(NULL);
379 			tm = localtime(&t);
380 			y = tm->tm_year + 1900;
381 			m = tm->tm_mon + 1;
382 		}
383 		break;
384 	default:
385 		usage();
386 	}
387 
388 	if (flag_month != NULL) {
389 		if (parsemonth(flag_month, &m, &y)) {
390 			errx(EX_USAGE,
391 			    "%s is neither a month number (1..12) nor a name",
392 			    flag_month);
393 		}
394 	}
395 
396 	/*
397 	 * What is not supported:
398 	 * -3 with -A or -B
399 	 *	-3 displays 3 months, -A and -B change that behaviour.
400 	 * -3 with -y
401 	 *	-3 displays 3 months, -y says display a whole year.
402 	 * -3 with a given year but no given month or without -m
403 	 *	-3 displays 3 months, no month specified doesn't make clear
404 	 *      which three months.
405 	 * -m with a given month
406 	 *	conflicting arguments, both specify the same field.
407 	 * -y with -m
408 	 *	-y displays the whole year, -m displays a single month.
409 	 * -y with a given month
410 	 *	-y displays the whole year, the given month displays a single
411 	 *	month.
412 	 * -y with -A or -B
413 	 *	-y displays the whole year, -A and -B display extra months.
414 	 */
415 
416 	/* -3 together with -A or -B. */
417 	if (flag_3months && (flag_after || flag_before))
418 		errx(EX_USAGE, "-3 together with -A and -B is not supported.");
419 	/* -3 together with -y. */
420 	if (flag_3months && flag_wholeyear)
421 		errx(EX_USAGE, "-3 together with -y is not supported.");
422 	/* -3 together with givenyear but no givenmonth. */
423 	if (flag_3months && flag_givenyear &&
424 	    !(flag_givenmonth || flag_specifiedmonth))
425 		errx(EX_USAGE,
426 		    "-3 together with a given year but no given month is "
427 		    "not supported.");
428 	/* -m together with xx xxxx. */
429 	if (flag_specifiedmonth && flag_givenmonth)
430 		errx(EX_USAGE,
431 		    "-m together with a given month is not supported.");
432 	/* -y together with -m. */
433 	if (flag_wholeyear && flag_specifiedmonth)
434 		errx(EX_USAGE, "-y together with -m is not supported.");
435 	/* -y together with xx xxxx. */
436 	if (flag_wholeyear && flag_givenmonth)
437 		errx(EX_USAGE, "-y together a given month is not supported.");
438 	/* -y together with -A or -B. */
439 	if (flag_wholeyear && (flag_before > 0 || flag_after > 0))
440 		errx(EX_USAGE, "-y together a -A or -B is not supported.");
441 	/* The rest should be fine. */
442 
443 	/* Select the period to display, in order of increasing priority .*/
444 	if (flag_wholeyear ||
445 	    (flag_givenyear && !(flag_givenmonth || flag_specifiedmonth))) {
446 		m = 1;
447 		before = 0;
448 		after = 11;
449 	}
450 	if (flag_givenyear && flag_givenmonth) {
451 		before = 0;
452 		after = 0;
453 	}
454 	if (flag_specifiedmonth) {
455 		before = 0;
456 		after = 0;
457 	}
458 	if (flag_before) {
459 		before = flag_before;
460 	}
461 	if (flag_after) {
462 		after = flag_after;
463 	}
464 	if (flag_3months) {
465 		before = 1;
466 		after = 1;
467 	}
468 	if (after == -1)
469 		after = 0;
470 	if (before == -1)
471 		before = 0;
472 
473 	/* Highlight a specified day or today .*/
474 	if (flag_highlightdate != NULL) {
475 		dt.y = strtol(flag_highlightdate, NULL, 10);
476 		dt.m = strtol(flag_highlightdate + 5, NULL, 10);
477 		dt.d = strtol(flag_highlightdate + 8, NULL, 10);
478 	} else {
479 		time_t t;
480 		struct tm *tm1;
481 
482 		t = time(NULL);
483 		tm1 = localtime(&t);
484 		dt.y = tm1->tm_year + 1900;
485 		dt.m = tm1->tm_mon + 1;
486 		dt.d = tm1->tm_mday;
487 	}
488 	highlightdate = sndaysb(&dt);
489 
490 	/* And now we finally start to calculate and output calendars. */
491 	if (flag_easter)
492 		printeaster(y, flag_julian_cal, flag_orthodox);
493 	else
494 		if (flag_backward)
495 			monthrangeb(y, m, flag_julian_day, before, after);
496 		else
497 			monthranger(y, m, flag_julian_day, before, after);
498 	if (ferror(stdout) != 0 || fflush(stdout) != 0)
499 		err(1, "stdout");
500 	return (0);
501 }
502 
503 static void
504 usage(void)
505 {
506 
507 	fputs(
508 "Usage: cal [general options] [-hjy] [[month] year]\n"
509 "       cal [general options] [-hj] [-m month] [year]\n"
510 "       ncal [general options] [-hJjpwy] [-s country_code] [[month] year]\n"
511 "       ncal [general options] [-hJeo] [year]\n"
512 "General options: [-NC3] [-A months] [-B months]\n"
513 "For debug the highlighting: [-H yyyy-mm-dd] [-d yyyy-mm]\n",
514 	    stderr);
515 	exit(EX_USAGE);
516 }
517 
518 /* Print the assumed switches for all countries. */
519 static void
520 printcc(void)
521 {
522 	struct djswitch *p;
523 	int n;	/* number of lines to print */
524 	int m;	/* offset from left to right table entry on the same line */
525 
526 #define FSTR "%c%s %-15s%4d-%02d-%02d"
527 #define DFLT(p) ((p) == dftswitch ? '*' : ' ')
528 #define FSTRARG(p) DFLT(p), (p)->cc, (p)->nm, (p)->dt.y, (p)->dt.m, (p)->dt.d
529 
530 	n = sizeof(switches) / sizeof(struct djswitch);
531 	m = (n + 1) / 2;
532 	n /= 2;
533 	for (p = switches; p != switches + n; p++)
534 		printf(FSTR"     "FSTR"\n", FSTRARG(p), FSTRARG(p+m));
535 	if (m != n)
536 		printf(FSTR"\n", FSTRARG(p));
537 }
538 
539 /* Print the date of easter sunday. */
540 static void
541 printeaster(int y, int julian, int orthodox)
542 {
543 	date    dt;
544 	struct tm tm;
545 	char    buf[MAX_WIDTH];
546 	static int d_first = -1;
547 
548 	if (d_first < 0)
549 		d_first = (*nl_langinfo(D_MD_ORDER) == 'd');
550 	/* force orthodox easter for years before 1583 */
551 	if (y < 1583)
552 		orthodox = 1;
553 
554 	if (orthodox)
555 		if (julian)
556 			easteroj(y, &dt);
557 		else
558 			easterog(y, &dt);
559 	else
560 		easterg(y, &dt);
561 
562 	memset(&tm, 0, sizeof(tm));
563 	tm.tm_year = dt.y - 1900;
564 	tm.tm_mon  = dt.m - 1;
565 	tm.tm_mday = dt.d;
566 	strftime(buf, sizeof(buf), d_first ? "%e %B %Y" : "%B %e %Y",  &tm);
567 	printf("%s\n", buf);
568 }
569 
570 #define MW(mw, me)		((mw) + me)
571 #define	DECREASEMONTH(m, y) 		\
572 		if (--m == 0) {		\
573 			m = 12;		\
574 			y--;		\
575 		}
576 #define	INCREASEMONTH(m, y)		\
577 		if (++(m) == 13) {	\
578 			(m) = 1;	\
579 			(y)++;		\
580 		}
581 #define	M2Y(m)	((m) / 12)
582 #define	M2M(m)	(1 + (m) % 12)
583 
584 /* Print all months for the period in the range [ before .. y-m .. after ]. */
585 static void
586 monthrangeb(int y, int m, int jd_flag, int before, int after)
587 {
588 	struct monthlines year[12];
589 	struct weekdays wds;
590 	char	s[MAX_WIDTH], t[MAX_WIDTH];
591 	wchar_t	ws[MAX_WIDTH], ws1[MAX_WIDTH];
592 	const char	*wdss;
593 	int     i, j;
594 	int     mpl;
595 	int     mw;
596 	int	m1, m2;
597 	int	printyearheader;
598 	int	prevyear = -1;
599 
600 	mpl = jd_flag ? 2 : 3;
601 	mw = jd_flag ? MONTH_WIDTH_B_J : MONTH_WIDTH_B;
602 	wdss = (mpl == 2) ? " " : "";
603 
604 	while (before != 0) {
605 		DECREASEMONTH(m, y);
606 		before--;
607 		after++;
608 	}
609 	m1 = y * 12 + m - 1;
610 	m2 = m1 + after;
611 
612 	mkweekdays(&wds);
613 
614 	/*
615 	 * The year header is printed when there are more than 'mpl' months
616 	 * and if the first month is a multitude of 'mpl'.
617 	 * If not, it will print the year behind every month.
618 	 */
619 	printyearheader = (after >= mpl - 1) && (M2M(m1) - 1) % mpl == 0;
620 
621 	m = m1;
622 	while (m <= m2) {
623 		int count = 0;
624 		for (i = 0; i != mpl && m + i <= m2; i++) {
625 			mkmonthb(M2Y(m + i), M2M(m + i) - 1, jd_flag, year + i);
626 			count++;
627 		}
628 
629 		/* Empty line between two rows of months */
630 		if (m != m1)
631 			printf("\n");
632 
633 		/* Year at the top. */
634 		if (printyearheader && M2Y(m) != prevyear) {
635 			sprintf(s, "%d", M2Y(m));
636 			printf("%s\n", center(t, s, mpl * mw));
637 			prevyear = M2Y(m);
638 		}
639 
640 		/* Month names. */
641 		for (i = 0; i < count; i++)
642 			if (printyearheader)
643 				wprintf(L"%-*ls  ",
644 				    mw, wcenter(ws, year[i].name, mw));
645 			else {
646 				swprintf(ws, sizeof(ws)/sizeof(ws[0]),
647 				    L"%-ls %d", year[i].name, M2Y(m + i));
648 				wprintf(L"%-*ls  ", mw, wcenter(ws1, ws, mw));
649 			}
650 		printf("\n");
651 
652 		/* Day of the week names. */
653 		for (i = 0; i < count; i++) {
654 			wprintf(L"%s%ls%s%ls%s%ls%s%ls%s%ls%s%ls%s%ls ",
655 				wdss, wds.names[6], wdss, wds.names[0],
656 				wdss, wds.names[1], wdss, wds.names[2],
657 				wdss, wds.names[3], wdss, wds.names[4],
658 				wdss, wds.names[5]);
659 		}
660 		printf("\n");
661 
662 		/* And the days of the month. */
663 		for (i = 0; i != 6; i++) {
664 			for (j = 0; j < count; j++)
665 				printf("%-*s  ",
666 				    MW(mw, year[j].extralen[i]),
667 					year[j].lines[i]+1);
668 			printf("\n");
669 		}
670 
671 		m += mpl;
672 	}
673 }
674 
675 static void
676 monthranger(int y, int m, int jd_flag, int before, int after)
677 {
678 	struct monthlines year[12];
679 	struct weekdays wds;
680 	char    s[MAX_WIDTH], t[MAX_WIDTH];
681 	int     i, j;
682 	int     mpl;
683 	int     mw;
684 	int	m1, m2;
685 	int	prevyear = -1;
686 	int	printyearheader;
687 
688 	mpl = jd_flag ? 3 : 4;
689 	mw = jd_flag ? MONTH_WIDTH_R_J : MONTH_WIDTH_R;
690 
691 	while (before != 0) {
692 		DECREASEMONTH(m, y);
693 		before--;
694 		after++;
695 	}
696 	m1 = y * 12 + m - 1;
697 	m2 = m1 + after;
698 
699 	mkweekdays(&wds);
700 
701 	/*
702 	 * The year header is printed when there are more than 'mpl' months
703 	 * and if the first month is a multitude of 'mpl'.
704 	 * If not, it will print the year behind every month.
705 	 */
706 	printyearheader = (after >= mpl - 1) && (M2M(m1) - 1) % mpl == 0;
707 
708 	m = m1;
709 	while (m <= m2) {
710 		int count = 0;
711 		for (i = 0; i != mpl && m + i <= m2; i++) {
712 			mkmonthr(M2Y(m + i), M2M(m + i) - 1, jd_flag, year + i);
713 			count++;
714 		}
715 
716 		/* Empty line between two rows of months. */
717 		if (m != m1)
718 			printf("\n");
719 
720 		/* Year at the top. */
721 		if (printyearheader && M2Y(m) != prevyear) {
722 			sprintf(s, "%d", M2Y(m));
723 			printf("%s\n", center(t, s, mpl * mw));
724 			prevyear = M2Y(m);
725 		}
726 
727 		/* Month names. */
728 		wprintf(L"    ");
729 		for (i = 0; i < count; i++)
730 			if (printyearheader)
731 				wprintf(L"%-*ls", mw, year[i].name);
732 			else
733 				wprintf(L"%-ls %-*d", year[i].name,
734 				    mw - wcslen(year[i].name) - 1, M2Y(m + i));
735 		printf("\n");
736 
737 		/* And the days of the month. */
738 		for (i = 0; i != 7; i++) {
739 			/* Week day */
740 			wprintf(L"%.2ls", wds.names[i]);
741 
742 			/* Full months */
743 			for (j = 0; j < count; j++)
744 				printf("%-*s",
745 				    MW(mw, year[j].extralen[i]),
746 					year[j].lines[i]);
747 			printf("\n");
748 		}
749 
750 		/* Week numbers. */
751 		if (flag_weeks) {
752 			printf("  ");
753 			for (i = 0; i < count; i++)
754 				printf("%-*s", mw, year[i].weeks);
755 			printf("\n");
756 		}
757 
758 		m += mpl;
759 	}
760 	return;
761 }
762 
763 static void
764 mkmonthr(int y, int m, int jd_flag, struct monthlines *mlines)
765 {
766 
767 	struct tm tm;		/* for strftime printing local names of
768 				 * months */
769 	date    dt;		/* handy date */
770 	int     dw;		/* width of numbers */
771 	int     first;		/* first day of month */
772 	int     firstm;		/* first day of first week of month */
773 	int     i, j, k, l;	/* just indices */
774 	int     last;		/* the first day of next month */
775 	int     jan1 = 0;	/* the first day of this year */
776 	char   *ds;		/* pointer to day strings (daystr or
777 				 * jdaystr) */
778 
779 	/* Set name of month. */
780 	memset(&tm, 0, sizeof(tm));
781 	tm.tm_mon = m;
782 	wcsftime(mlines->name, sizeof(mlines->name) / sizeof(mlines->name[0]),
783 		 L"%OB", &tm);
784 	mlines->name[0] = towupper(mlines->name[0]);
785 
786 	/*
787 	 * Set first and last to the day number of the first day of this
788 	 * month and the first day of next month respectively. Set jan1 to
789 	 * the day number of the first day of this year.
790 	 */
791 	first = firstday(y, m + 1);
792 	if (m == 11)
793 		last = firstday(y + 1, 1);
794 	else
795 		last = firstday(y, m + 2);
796 
797 	if (jd_flag)
798 		jan1 = firstday(y, 1);
799 
800 	/*
801 	 * Set firstm to the day number of monday of the first week of
802 	 * this month. (This might be in the last month)
803 	 */
804 	firstm = first - weekday(first);
805 
806 	/* Set ds (daystring) and dw (daywidth) according to the jd_flag. */
807 	if (jd_flag) {
808 		ds = jdaystr;
809 		dw = 4;
810 	} else {
811 		ds = daystr;
812 		dw = 3;
813 	}
814 
815 	/*
816 	 * Fill the lines with day of month or day of year (julian day)
817 	 * line index: i, each line is one weekday. column index: j, each
818 	 * column is one day number. print column index: k.
819 	 */
820 	for (i = 0; i != 7; i++) {
821 		l = 0;
822 		for (j = firstm + i, k = 0; j < last; j += 7, k += dw) {
823 			if (j >= first) {
824 				if (jd_flag)
825 					dt.d = j - jan1 + 1;
826 				else
827 					sdater(j, &dt);
828 				if (j == highlightdate && !flag_nohighlight
829 				 && isatty(STDOUT_FILENO))
830 					highlight(mlines->lines[i] + k,
831 					    ds + dt.d * dw, dw, &l);
832 				else
833 					memcpy(mlines->lines[i] + k + l,
834 					       ds + dt.d * dw, dw);
835 			} else
836 				memcpy(mlines->lines[i] + k + l, "    ", dw);
837 		}
838 		mlines->lines[i][k + l] = '\0';
839 		mlines->extralen[i] = l;
840 	}
841 
842 	/* fill the weeknumbers. */
843 	if (flag_weeks) {
844 		for (j = firstm, k = 0; j < last;  k += dw, j += 7)
845 			if (j <= nswitch)
846 				memset(mlines->weeks + k, ' ', dw);
847 			else
848 				memcpy(mlines->weeks + k,
849 				    ds + week(j, &i)*dw, dw);
850 		mlines->weeks[k] = '\0';
851 	}
852 }
853 
854 static void
855 mkmonthb(int y, int m, int jd_flag, struct monthlines *mlines)
856 {
857 
858 	struct tm tm;		/* for strftime printing local names of
859 				 * months */
860 	date    dt;		/* handy date */
861 	int     dw;		/* width of numbers */
862 	int     first;		/* first day of month */
863 	int     firsts;		/* sunday of first week of month */
864 	int     i, j, k, l;	/* just indices */
865 	int     jan1 = 0;	/* the first day of this year */
866 	int     last;		/* the first day of next month */
867 	char   *ds;		/* pointer to day strings (daystr or
868 				 * jdaystr) */
869 
870 	/* Set ds (daystring) and dw (daywidth) according to the jd_flag */
871 	if (jd_flag) {
872 		ds = jdaystr;
873 		dw = 4;
874 	} else {
875 		ds = daystr;
876 		dw = 3;
877 	}
878 
879 	/* Set name of month centered. */
880 	memset(&tm, 0, sizeof(tm));
881 	tm.tm_mon = m;
882 	wcsftime(mlines->name, sizeof(mlines->name) / sizeof(mlines->name[0]),
883 		 L"%OB", &tm);
884 	mlines->name[0] = towupper(mlines->name[0]);
885 
886 	/*
887 	 * Set first and last to the day number of the first day of this
888 	 * month and the first day of next month respectively. Set jan1 to
889 	 * the day number of Jan 1st of this year.
890 	 */
891 	dt.y = y;
892 	dt.m = m + 1;
893 	dt.d = 1;
894 	first = sndaysb(&dt);
895 	if (m == 11) {
896 		dt.y = y + 1;
897 		dt.m = 1;
898 		dt.d = 1;
899 	} else {
900 		dt.y = y;
901 		dt.m = m + 2;
902 		dt.d = 1;
903 	}
904 	last = sndaysb(&dt);
905 
906 	if (jd_flag) {
907 		dt.y = y;
908 		dt.m = 1;
909 		dt.d = 1;
910 		jan1 = sndaysb(&dt);
911 	}
912 
913 	/*
914 	 * Set firsts to the day number of sunday of the first week of
915 	 * this month. (This might be in the last month)
916 	 */
917 	firsts = first - (weekday(first)+1) % 7;
918 
919 	/*
920 	 * Fill the lines with day of month or day of year (Julian day)
921 	 * line index: i, each line is one week. column index: j, each
922 	 * column is one day number. print column index: k.
923 	 */
924 	for (i = 0; i != 6; i++) {
925 		l = 0;
926 		for (j = firsts + 7 * i, k = 0; j < last && k != dw * 7;
927 		    j++, k += dw) {
928 			if (j >= first) {
929 				if (jd_flag)
930 					dt.d = j - jan1 + 1;
931 				else
932 					sdateb(j, &dt);
933 				if (j == highlightdate && !flag_nohighlight
934 				 && isatty(STDOUT_FILENO))
935 					highlight(mlines->lines[i] + k,
936 					    ds + dt.d * dw, dw, &l);
937 				else
938 					memcpy(mlines->lines[i] + k + l,
939 					       ds + dt.d * dw, dw);
940 			} else
941 				memcpy(mlines->lines[i] + k + l, "    ", dw);
942 		}
943 		if (k == 0)
944 			mlines->lines[i][1] = '\0';
945 		else
946 			mlines->lines[i][k + l] = '\0';
947 		mlines->extralen[i] = l;
948 	}
949 }
950 
951 /* Put the local names of weekdays into the wds. */
952 static void
953 mkweekdays(struct weekdays *wds)
954 {
955 	int i, len, width = 0;
956 	struct tm tm;
957 	wchar_t buf[20];
958 
959 	memset(&tm, 0, sizeof(tm));
960 
961 	for (i = 0; i != 7; i++) {
962 		tm.tm_wday = (i+1) % 7;
963 		wcsftime(buf, sizeof(buf)/sizeof(buf[0]), L"%a", &tm);
964 		for (len = 2; len > 0; --len) {
965 			if ((width = wcswidth(buf, len)) <= 2)
966 				break;
967 		}
968 		wmemset(wds->names[i], L'\0', 4);
969 		if (width == 1)
970 			wds->names[i][0] = L' ';
971 		wcsncat(wds->names[i], buf, len);
972 		wcsncat(wds->names[i], L" ", 1);
973 	}
974 }
975 
976 /*
977  * Compute the day number of the first existing date after the first day in
978  * month. (the first day in month and even the month might not exist!)
979  */
980 static int
981 firstday(int y, int m)
982 {
983 	date dt;
984 	int nd;
985 
986 	dt.y = y;
987 	dt.m = m;
988 	dt.d = 1;
989 	nd = sndaysr(&dt);
990 	for (;;) {
991 		sdater(nd, &dt);
992 		if ((dt.m >= m && dt.y == y) || dt.y > y)
993 			return (nd);
994 		else
995 			nd++;
996 	}
997 	/* NEVER REACHED */
998 }
999 
1000 /*
1001  * Compute the number of days from date, obey the local switch from
1002  * Julian to Gregorian if specified by the user.
1003  */
1004 static int
1005 sndaysr(struct date *d)
1006 {
1007 
1008 	if (nswitch != 0)
1009 		if (nswitch < ndaysj(d))
1010 			return (ndaysg(d));
1011 		else
1012 			return (ndaysj(d));
1013 	else
1014 		return ndaysg(d);
1015 }
1016 
1017 /*
1018  * Compute the number of days from date, obey the switch from
1019  * Julian to Gregorian as used by UK and her colonies.
1020  */
1021 static int
1022 sndaysb(struct date *d)
1023 {
1024 
1025 	if (nswitchb < ndaysj(d))
1026 		return (ndaysg(d));
1027 	else
1028 		return (ndaysj(d));
1029 }
1030 
1031 /* Inverse of sndays. */
1032 static struct date *
1033 sdater(int nd, struct date *d)
1034 {
1035 
1036 	if (nswitch < nd)
1037 		return (gdate(nd, d));
1038 	else
1039 		return (jdate(nd, d));
1040 }
1041 
1042 /* Inverse of sndaysb. */
1043 static struct date *
1044 sdateb(int nd, struct date *d)
1045 {
1046 
1047 	if (nswitchb < nd)
1048 		return (gdate(nd, d));
1049 	else
1050 		return (jdate(nd, d));
1051 }
1052 
1053 /* Center string t in string s of length w by putting enough leading blanks. */
1054 static char *
1055 center(char *s, char *t, int w)
1056 {
1057 	char blanks[MAX_WIDTH];
1058 
1059 	memset(blanks, ' ', sizeof(blanks));
1060 	sprintf(s, "%.*s%s", (int)(w - strlen(t)) / 2, blanks, t);
1061 	return (s);
1062 }
1063 
1064 /* Center string t in string s of length w by putting enough leading blanks. */
1065 static wchar_t *
1066 wcenter(wchar_t *s, wchar_t *t, int w)
1067 {
1068 	char blanks[MAX_WIDTH];
1069 
1070 	memset(blanks, ' ', sizeof(blanks));
1071 	swprintf(s, MAX_WIDTH, L"%.*s%ls", (int)(w - wcslen(t)) / 2, blanks, t);
1072 	return (s);
1073 }
1074 
1075 static int
1076 parsemonth(const char *s, int *m, int *y)
1077 {
1078 	int nm, ny;
1079 	char *cp;
1080 	struct tm tm;
1081 
1082 	nm = (int)strtol(s, &cp, 10);
1083 	if (cp != s) {
1084 		ny = *y;
1085 		if (*cp == '\0') {
1086 			;	/* no special action */
1087 		} else if (*cp == 'f' || *cp == 'F') {
1088 			if (nm <= *m)
1089 				ny++;
1090 		} else if (*cp == 'p' || *cp == 'P') {
1091 			if (nm >= *m)
1092 				ny--;
1093 		} else
1094 			return (1);
1095 		if (nm < 1 || nm > 12)
1096 			return 1;
1097 		*m = nm;
1098 		*y = ny;
1099 		return (0);
1100 	}
1101 	if (strptime(s, "%B", &tm) != NULL || strptime(s, "%b", &tm) != NULL) {
1102 		*m = tm.tm_mon + 1;
1103 		return (0);
1104 	}
1105 	return (1);
1106 }
1107 
1108 static void
1109 highlight(char *dst, char *src, int len, int *extralen)
1110 {
1111 	static int first = 1;
1112 	static const char *term_so, *term_se;
1113 
1114 	if (first) {
1115 		static char cbuf[512];
1116 		char tbuf[1024], *b;
1117 
1118 		term_se = term_so = NULL;
1119 
1120 		/* On how to highlight on this type of terminal (if any). */
1121 		if (isatty(STDOUT_FILENO) && tgetent(tbuf, NULL) == 1) {
1122 			b = cbuf;
1123 			term_so = tgetstr("so", &b);
1124 			term_se = tgetstr("se", &b);
1125 		}
1126 
1127 		first = 0;
1128 	}
1129 
1130 	/*
1131 	 * This check is not necessary, should have been handled before calling
1132 	 * this function.
1133 	 */
1134 	if (flag_nohighlight) {
1135 		memcpy(dst, src, len);
1136 		return;
1137 	}
1138 
1139 	/*
1140 	 * If it is a real terminal, use the data from the termcap database.
1141 	 */
1142 	if (term_so != NULL && term_se != NULL) {
1143 		/* separator. */
1144 		dst[0] = ' ';
1145 		dst++;
1146 		/* highlight on. */
1147 		memcpy(dst, term_so, strlen(term_so));
1148 		dst += strlen(term_so);
1149 		/* the actual text. (minus leading space) */
1150 		len--;
1151 		src++;
1152 		memcpy(dst, src, len);
1153 		dst += len;
1154 		/* highlight off. */
1155 		memcpy(dst, term_se, strlen(term_se));
1156 		*extralen = strlen(term_so) + strlen(term_se);
1157 		return;
1158 	}
1159 
1160 	/*
1161 	 * Otherwise, print a _, backspace and the letter.
1162 	 */
1163 	*extralen = 0;
1164 	/* skip leading space. */
1165 	src++;
1166 	len--;
1167 	/* separator. */
1168 	dst[0] = ' ';
1169 	dst++;
1170 	while (len > 0) {
1171 		/* _ and backspace. */
1172 		memcpy(dst, "_\010", 2);
1173 		dst += 2;
1174 		*extralen += 2;
1175 		/* the character. */
1176 		*dst++ = *src++;
1177 		len--;
1178 	}
1179 	return;
1180 }
1181