1/*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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__FBSDID("$FreeBSD$");
31
32#include <calendar.h>
33#include <ctype.h>
34#include <err.h>
35#include <langinfo.h>
36#include <libgen.h>
37#include <locale.h>
38#include <stdio.h>
39#include <stdlib.h>
40#include <string.h>
41#include <sysexits.h>
42#include <time.h>
43#include <unistd.h>
44#include <wchar.h>
45#include <wctype.h>
46#include <term.h>
47#undef lines			/* term.h defines this */
48
49/* Width of one month with backward compatibility and in regular mode*/
50#define MONTH_WIDTH_B_J 27
51#define MONTH_WIDTH_B 20
52
53#define MONTH_WIDTH_R_J 24
54#define MONTH_WIDTH_R 18
55
56#define MAX_WIDTH 64
57
58typedef struct date date;
59
60struct monthlines {
61	wchar_t name[MAX_WIDTH + 1];
62	char lines[7][MAX_WIDTH + 1];
63	char weeks[MAX_WIDTH + 1];
64	unsigned int extralen[7];
65};
66
67struct weekdays {
68	wchar_t names[7][4];
69};
70
71/* The switches from Julian to Gregorian in some countries */
72static struct djswitch {
73	const char *cc;	/* Country code according to ISO 3166 */
74	const char *nm;	/* Name of country */
75	date dt;	/* Last day of Julian calendar */
76} switches[] = {
77	{"AL", "Albania",       {1912, 11, 30}},
78	{"AT", "Austria",       {1583, 10,  5}},
79	{"AU", "Australia",     {1752,  9,  2}},
80	{"BE", "Belgium",       {1582, 12, 14}},
81	{"BG", "Bulgaria",      {1916,  3, 31}},
82	{"CA", "Canada",        {1752,  9,  2}},
83	{"CH", "Switzerland",   {1655,  2, 28}},
84	{"CN", "China",         {1911, 12, 18}},
85	{"CZ", "Czech Republic",{1584,  1,  6}},
86	{"DE", "Germany",       {1700,  2, 18}},
87	{"DK", "Denmark",       {1700,  2, 18}},
88	{"ES", "Spain",         {1582, 10,  4}},
89	{"FI", "Finland",       {1753,  2, 17}},
90	{"FR", "France",        {1582, 12,  9}},
91	{"GB", "United Kingdom",{1752,  9,  2}},
92	{"GR", "Greece",        {1924,  3,  9}},
93	{"HU", "Hungary",       {1587, 10, 21}},
94	{"IS", "Iceland",       {1700, 11, 16}},
95	{"IT", "Italy",         {1582, 10,  4}},
96	{"JP", "Japan",         {1918, 12, 18}},
97	{"LI", "Lithuania",     {1918,  2,  1}},
98	{"LN", "Latin",         {9999, 05, 31}},
99	{"LU", "Luxembourg",    {1582, 12, 14}},
100	{"LV", "Latvia",        {1918,  2,  1}},
101	{"NL", "Netherlands",   {1582, 12, 14}},
102	{"NO", "Norway",        {1700,  2, 18}},
103	{"PL", "Poland",        {1582, 10,  4}},
104	{"PT", "Portugal",      {1582, 10,  4}},
105	{"RO", "Romania",       {1919,  3, 31}},
106	{"RU", "Russia",        {1918,  1, 31}},
107	{"SI", "Slovenia",      {1919,  3,  4}},
108	{"SE", "Sweden",        {1753,  2, 17}},
109	{"TR", "Turkey",        {1926, 12, 18}},
110	{"US", "United States", {1752,  9,  2}},
111	{"YU", "Yugoslavia",    {1919,  3,  4}}
112};
113
114static struct djswitch *dftswitch =
115    switches + sizeof(switches) / sizeof(struct djswitch) - 2;
116    /* default switch (should be "US") */
117
118/* Table used to print day of month and week numbers */
119static char daystr[] = "     1  2  3  4  5  6  7  8  9 10 11 12 13 14 15"
120		       " 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31"
121		       " 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47"
122		       " 48 49 50 51 52 53";
123
124/* Table used to print day of year and week numbers */
125static char jdaystr[] = "       1   2   3   4   5   6   7   8   9"
126			"  10  11  12  13  14  15  16  17  18  19"
127			"  20  21  22  23  24  25  26  27  28  29"
128			"  30  31  32  33  34  35  36  37  38  39"
129			"  40  41  42  43  44  45  46  47  48  49"
130			"  50  51  52  53  54  55  56  57  58  59"
131			"  60  61  62  63  64  65  66  67  68  69"
132			"  70  71  72  73  74  75  76  77  78  79"
133			"  80  81  82  83  84  85  86  87  88  89"
134			"  90  91  92  93  94  95  96  97  98  99"
135			" 100 101 102 103 104 105 106 107 108 109"
136			" 110 111 112 113 114 115 116 117 118 119"
137			" 120 121 122 123 124 125 126 127 128 129"
138			" 130 131 132 133 134 135 136 137 138 139"
139			" 140 141 142 143 144 145 146 147 148 149"
140			" 150 151 152 153 154 155 156 157 158 159"
141			" 160 161 162 163 164 165 166 167 168 169"
142			" 170 171 172 173 174 175 176 177 178 179"
143			" 180 181 182 183 184 185 186 187 188 189"
144			" 190 191 192 193 194 195 196 197 198 199"
145			" 200 201 202 203 204 205 206 207 208 209"
146			" 210 211 212 213 214 215 216 217 218 219"
147			" 220 221 222 223 224 225 226 227 228 229"
148			" 230 231 232 233 234 235 236 237 238 239"
149			" 240 241 242 243 244 245 246 247 248 249"
150			" 250 251 252 253 254 255 256 257 258 259"
151			" 260 261 262 263 264 265 266 267 268 269"
152			" 270 271 272 273 274 275 276 277 278 279"
153			" 280 281 282 283 284 285 286 287 288 289"
154			" 290 291 292 293 294 295 296 297 298 299"
155			" 300 301 302 303 304 305 306 307 308 309"
156			" 310 311 312 313 314 315 316 317 318 319"
157			" 320 321 322 323 324 325 326 327 328 329"
158			" 330 331 332 333 334 335 336 337 338 339"
159			" 340 341 342 343 344 345 346 347 348 349"
160			" 350 351 352 353 354 355 356 357 358 359"
161			" 360 361 362 363 364 365 366";
162
163static int flag_nohighlight;	/* user doesn't want a highlighted today */
164static int flag_weeks;		/* user wants number of week */
165static int nswitch;		/* user defined switch date */
166static int nswitchb;		/* switch date for backward compatibility */
167static int highlightdate;
168
169static char	*center(char *s, char *t, int w);
170static wchar_t *wcenter(wchar_t *s, wchar_t *t, int w);
171static int	firstday(int y, int m);
172static void	highlight(char *dst, char *src, int len, int *extraletters);
173static void	mkmonthr(int year, int month, int jd_flag,
174    struct monthlines * monthl);
175static void	mkmonthb(int year, int month, int jd_flag,
176    struct monthlines * monthl);
177static void	mkweekdays(struct weekdays * wds);
178static void	monthranger(int year, int m, int jd_flag,
179    int before, int after);
180static void	monthrangeb(int year, int m, int jd_flag,
181    int before, int after);
182static int	parsemonth(const char *s, int *m, int *y);
183static void	printcc(void);
184static void	printeaster(int year, int julian, int orthodox);
185static date	*sdater(int ndays, struct date * d);
186static date	*sdateb(int ndays, struct date * d);
187static int	sndaysr(struct date * d);
188static int	sndaysb(struct date * d);
189static void	usage(void);
190
191int
192main(int argc, char *argv[])
193{
194	struct  djswitch *p, *q;	/* to search user defined switch date */
195	date	never = {10000, 1, 1};	/* outside valid range of dates */
196	date	ukswitch = {1752, 9, 2};/* switch date for Great Britain */
197	date	dt;
198	int     ch;			/* holds the option character */
199	int     m = 0;			/* month */
200	int	y = 0;			/* year */
201	int     flag_backward = 0;	/* user called cal--backward compat. */
202	int     flag_wholeyear = 0;	/* user wants the whole year */
203	int	flag_julian_cal = 0;	/* user wants Julian Calendar */
204	int     flag_julian_day = 0;	/* user wants the Julian day numbers */
205	int	flag_orthodox = 0;	/* user wants Orthodox easter */
206	int	flag_easter = 0;	/* user wants easter date */
207	int	flag_3months = 0;	/* user wants 3 month display (-3) */
208	int	flag_after = 0;		/* user wants to see months after */
209	int	flag_before = 0;	/* user wants to see months before */
210	int	flag_specifiedmonth = 0;/* user wants to see this month (-m) */
211	int	flag_givenmonth = 0;	/* user has specified month [n] */
212	int	flag_givenyear = 0;	/* user has specified year [n] */
213	char	*cp;			/* character pointer */
214	char	*flag_today = NULL;	/* debug: use date as being today */
215	char	*flag_month = NULL;	/* requested month as string */
216	char	*flag_highlightdate = NULL; /* debug: date to highlight */
217	int	before, after;
218	const char    *locale;		/* locale to get country code */
219
220	flag_nohighlight = 0;
221	flag_weeks = 0;
222
223	/*
224	 * Use locale to determine the country code,
225	 * and use the country code to determine the default
226	 * switchdate and date format from the switches table.
227	 */
228	if (setlocale(LC_ALL, "") == NULL)
229		warn("setlocale");
230	locale = setlocale(LC_TIME, NULL);
231	if (locale == NULL ||
232	    strcmp(locale, "C") == 0 ||
233	    strcmp(locale, "POSIX") == 0 ||
234	    strcmp(locale, "ASCII") == 0 ||
235	    strcmp(locale, "US-ASCII") == 0)
236		locale = "_US";
237	q = switches + sizeof(switches) / sizeof(struct djswitch);
238	for (p = switches; p != q; p++)
239		if ((cp = strstr(locale, p->cc)) != NULL && *(cp - 1) == '_')
240			break;
241	if (p == q) {
242		nswitch = ndaysj(&dftswitch->dt);
243	} else {
244		nswitch = ndaysj(&p->dt);
245		dftswitch = p;
246	}
247
248
249	/*
250	 * Get the filename portion of argv[0] and set flag_backward if
251	 * this program is called "cal".
252	 */
253	if (strncmp(basename(argv[0]), "cal", strlen("cal")) == 0)
254		flag_backward = 1;
255
256	/* Set the switch date to United Kingdom if backwards compatible */
257	if (flag_backward)
258		nswitchb = ndaysj(&ukswitch);
259
260	before = after = -1;
261
262	while ((ch = getopt(argc, argv, "3A:B:Cd:eH:hjJm:Nops:wy")) != -1)
263		switch (ch) {
264		case '3':
265			flag_3months = 1;
266			break;
267		case 'A':
268			if (flag_after > 0)
269				errx(EX_USAGE, "Double -A specified");
270			flag_after = strtol(optarg, NULL, 10);
271			if (flag_after <= 0)
272				errx(EX_USAGE,
273				    "Argument to -A must be positive");
274			break;
275		case 'B':
276			if (flag_before > 0)
277				errx(EX_USAGE, "Double -A specified");
278			flag_before = strtol(optarg, NULL, 10);
279			if (flag_before <= 0)
280				errx(EX_USAGE,
281				    "Argument to -B must be positive");
282			break;
283		case 'J':
284			if (flag_backward)
285				usage();
286			nswitch = ndaysj(&never);
287			flag_julian_cal = 1;
288			break;
289		case 'C':
290			flag_backward = 1;
291			break;
292		case 'N':
293			flag_backward = 0;
294			break;
295		case 'd':
296			flag_today = optarg;
297			break;
298		case 'H':
299			flag_highlightdate = optarg;
300			break;
301		case 'h':
302			flag_nohighlight = 1;
303			break;
304		case 'e':
305			if (flag_backward)
306				usage();
307			flag_easter = 1;
308			break;
309		case 'j':
310			flag_julian_day = 1;
311			break;
312		case 'm':
313			if (flag_specifiedmonth)
314				errx(EX_USAGE, "Double -m specified");
315			flag_month = optarg;
316			flag_specifiedmonth = 1;
317			break;
318		case 'o':
319			if (flag_backward)
320				usage();
321			flag_orthodox = 1;
322			flag_easter = 1;
323			break;
324		case 'p':
325			if (flag_backward)
326				usage();
327			printcc();
328			return (0);
329			break;
330		case 's':
331			if (flag_backward)
332				usage();
333			q = switches +
334			    sizeof(switches) / sizeof(struct djswitch);
335			for (p = switches;
336			     p != q && strcmp(p->cc, optarg) != 0; p++)
337				;
338			if (p == q)
339				errx(EX_USAGE,
340				    "%s: invalid country code", optarg);
341			nswitch = ndaysj(&(p->dt));
342			break;
343		case 'w':
344			if (flag_backward)
345				usage();
346			flag_weeks = 1;
347			break;
348		case 'y':
349			flag_wholeyear = 1;
350			break;
351		default:
352			usage();
353		}
354
355	argc -= optind;
356	argv += optind;
357
358	switch (argc) {
359	case 2:
360		if (flag_easter)
361			usage();
362		flag_month = *argv++;
363		flag_givenmonth = 1;
364		m = strtol(flag_month, NULL, 10);
365		/* FALLTHROUGH */
366	case 1:
367		y = atoi(*argv);
368		if (y < 1 || y > 9999)
369			errx(EX_USAGE, "year `%s' not in range 1..9999", *argv);
370		argv++;
371		flag_givenyear = 1;
372		break;
373	case 0:
374		if (flag_today != NULL) {
375			y = strtol(flag_today, NULL, 10);
376			m = strtol(flag_today + 5, NULL, 10);
377		} else {
378			time_t t;
379			struct tm *tm;
380
381			t = time(NULL);
382			tm = localtime(&t);
383			y = tm->tm_year + 1900;
384			m = tm->tm_mon + 1;
385		}
386		break;
387	default:
388		usage();
389	}
390
391	if (flag_month != NULL) {
392		if (parsemonth(flag_month, &m, &y)) {
393			errx(EX_USAGE,
394			    "%s is neither a month number (1..12) nor a name",
395			    flag_month);
396		}
397	}
398
399	/*
400	 * What is not supported:
401	 * -3 with -A or -B
402	 *	-3 displays 3 months, -A and -B change that behaviour.
403	 * -3 with -y
404	 *	-3 displays 3 months, -y says display a whole year.
405	 * -3 with a given year but no given month or without -m
406	 *	-3 displays 3 months, no month specified doesn't make clear
407	 *      which three months.
408	 * -m with a given month
409	 *	conflicting arguments, both specify the same field.
410	 * -y with -m
411	 *	-y displays the whole year, -m displays a single month.
412	 * -y with a given month
413	 *	-y displays the whole year, the given month displays a single
414	 *	month.
415	 * -y with -A or -B
416	 *	-y displays the whole year, -A and -B display extra months.
417	 */
418
419	/* -3 together with -A or -B. */
420	if (flag_3months && (flag_after || flag_before))
421		errx(EX_USAGE, "-3 together with -A and -B is not supported.");
422	/* -3 together with -y. */
423	if (flag_3months && flag_wholeyear)
424		errx(EX_USAGE, "-3 together with -y is not supported.");
425	/* -3 together with givenyear but no givenmonth. */
426	if (flag_3months && flag_givenyear &&
427	    !(flag_givenmonth || flag_specifiedmonth))
428		errx(EX_USAGE,
429		    "-3 together with a given year but no given month is "
430		    "not supported.");
431	/* -m together with xx xxxx. */
432	if (flag_specifiedmonth && flag_givenmonth)
433		errx(EX_USAGE,
434		    "-m together with a given month is not supported.");
435	/* -y together with -m. */
436	if (flag_wholeyear && flag_specifiedmonth)
437		errx(EX_USAGE, "-y together with -m is not supported.");
438	/* -y together with xx xxxx. */
439	if (flag_wholeyear && flag_givenmonth)
440		errx(EX_USAGE, "-y together a given month is not supported.");
441	/* -y together with -A or -B. */
442	if (flag_wholeyear && (flag_before > 0 || flag_after > 0))
443		errx(EX_USAGE, "-y together a -A or -B is not supported.");
444	/* The rest should be fine. */
445
446	/* Select the period to display, in order of increasing priority .*/
447	if (flag_wholeyear ||
448	    (flag_givenyear && !(flag_givenmonth || flag_specifiedmonth))) {
449		m = 1;
450		before = 0;
451		after = 11;
452	}
453	if (flag_givenyear && flag_givenmonth) {
454		before = 0;
455		after = 0;
456	}
457	if (flag_specifiedmonth) {
458		before = 0;
459		after = 0;
460	}
461	if (flag_before) {
462		before = flag_before;
463	}
464	if (flag_after) {
465		after = flag_after;
466	}
467	if (flag_3months) {
468		before = 1;
469		after = 1;
470	}
471	if (after == -1)
472		after = 0;
473	if (before == -1)
474		before = 0;
475
476	/* Highlight a specified day or today .*/
477	if (flag_highlightdate != NULL) {
478		dt.y = strtol(flag_highlightdate, NULL, 10);
479		dt.m = strtol(flag_highlightdate + 5, NULL, 10);
480		dt.d = strtol(flag_highlightdate + 8, NULL, 10);
481	} else {
482		time_t t;
483		struct tm *tm1;
484
485		t = time(NULL);
486		tm1 = localtime(&t);
487		dt.y = tm1->tm_year + 1900;
488		dt.m = tm1->tm_mon + 1;
489		dt.d = tm1->tm_mday;
490	}
491	highlightdate = sndaysb(&dt);
492
493	/* And now we finally start to calculate and output calendars. */
494	if (flag_easter)
495		printeaster(y, flag_julian_cal, flag_orthodox);
496	else
497		if (flag_backward)
498			monthrangeb(y, m, flag_julian_day, before, after);
499		else
500			monthranger(y, m, flag_julian_day, before, after);
501	return (0);
502}
503
504static void
505usage(void)
506{
507
508	fputs(
509"Usage: cal [general options] [-hjy] [[month] year]\n"
510"       cal [general options] [-hj] [-m month] [year]\n"
511"       ncal [general options] [-hJjpwy] [-s country_code] [[month] year]\n"
512"       ncal [general options] [-hJeo] [year]\n"
513"General options: [-NC3] [-A months] [-B months]\n"
514"For debug the highlighting: [-H yyyy-mm-dd] [-d yyyy-mm]\n",
515	    stderr);
516	exit(EX_USAGE);
517}
518
519/* Print the assumed switches for all countries. */
520static void
521printcc(void)
522{
523	struct djswitch *p;
524	int n;	/* number of lines to print */
525	int m;	/* offset from left to right table entry on the same line */
526
527#define FSTR "%c%s %-15s%4d-%02d-%02d"
528#define DFLT(p) ((p) == dftswitch ? '*' : ' ')
529#define FSTRARG(p) DFLT(p), (p)->cc, (p)->nm, (p)->dt.y, (p)->dt.m, (p)->dt.d
530
531	n = sizeof(switches) / sizeof(struct djswitch);
532	m = (n + 1) / 2;
533	n /= 2;
534	for (p = switches; p != switches + n; p++)
535		printf(FSTR"     "FSTR"\n", FSTRARG(p), FSTRARG(p+m));
536	if (m != n)
537		printf(FSTR"\n", FSTRARG(p));
538}
539
540/* Print the date of easter sunday. */
541static void
542printeaster(int y, int julian, int orthodox)
543{
544	date    dt;
545	struct tm tm;
546	char    buf[MAX_WIDTH];
547	static int d_first = -1;
548
549	if (d_first < 0)
550		d_first = (*nl_langinfo(D_MD_ORDER) == 'd');
551	/* force orthodox easter for years before 1583 */
552	if (y < 1583)
553		orthodox = 1;
554
555	if (orthodox)
556		if (julian)
557			easteroj(y, &dt);
558		else
559			easterog(y, &dt);
560	else
561		easterg(y, &dt);
562
563	memset(&tm, 0, sizeof(tm));
564	tm.tm_year = dt.y - 1900;
565	tm.tm_mon  = dt.m - 1;
566	tm.tm_mday = dt.d;
567	strftime(buf, sizeof(buf), d_first ? "%e %B %Y" : "%B %e %Y",  &tm);
568	printf("%s\n", buf);
569}
570
571#define MW(mw, me)		((mw) + me)
572#define	DECREASEMONTH(m, y) 		\
573		if (--m == 0) {		\
574			m = 12;		\
575			y--;		\
576		}
577#define	INCREASEMONTH(m, y)		\
578		if (++(m) == 13) {	\
579			(m) = 1;	\
580			(y)++;		\
581		}
582#define	M2Y(m)	((m) / 12)
583#define	M2M(m)	(1 + (m) % 12)
584
585/* Print all months for the period in the range [ before .. y-m .. after ]. */
586static void
587monthrangeb(int y, int m, int jd_flag, int before, int after)
588{
589	struct monthlines year[12];
590	struct weekdays wds;
591	char	s[MAX_WIDTH], t[MAX_WIDTH];
592	wchar_t	ws[MAX_WIDTH], ws1[MAX_WIDTH];
593	const char	*wdss;
594	int     i, j;
595	int     mpl;
596	int     mw;
597	int	m1, m2;
598	int	printyearheader;
599	int	prevyear = -1;
600
601	mpl = jd_flag ? 2 : 3;
602	mw = jd_flag ? MONTH_WIDTH_B_J : MONTH_WIDTH_B;
603	wdss = (mpl == 2) ? " " : "";
604
605	while (before != 0) {
606		DECREASEMONTH(m, y);
607		before--;
608		after++;
609	}
610	m1 = y * 12 + m - 1;
611	m2 = m1 + after;
612
613	mkweekdays(&wds);
614
615	/*
616	 * The year header is printed when there are more than 'mpl' months
617	 * and if the first month is a multitude of 'mpl'.
618	 * If not, it will print the year behind every month.
619	 */
620	printyearheader = (after >= mpl - 1) && (M2M(m1) - 1) % mpl == 0;
621
622	m = m1;
623	while (m <= m2) {
624		int count = 0;
625		for (i = 0; i != mpl && m + i <= m2; i++) {
626			mkmonthb(M2Y(m + i), M2M(m + i) - 1, jd_flag, year + i);
627			count++;
628		}
629
630		/* Empty line between two rows of months */
631		if (m != m1)
632			printf("\n");
633
634		/* Year at the top. */
635		if (printyearheader && M2Y(m) != prevyear) {
636			sprintf(s, "%d", M2Y(m));
637			printf("%s\n", center(t, s, mpl * mw));
638			prevyear = M2Y(m);
639		}
640
641		/* Month names. */
642		for (i = 0; i < count; i++)
643			if (printyearheader)
644				wprintf(L"%-*ls  ",
645				    mw, wcenter(ws, year[i].name, mw));
646			else {
647				swprintf(ws, sizeof(ws)/sizeof(ws[0]),
648				    L"%-ls %d", year[i].name, M2Y(m + i));
649				wprintf(L"%-*ls  ", mw, wcenter(ws1, ws, mw));
650			}
651		printf("\n");
652
653		/* Day of the week names. */
654		for (i = 0; i < count; i++) {
655			wprintf(L"%s%ls%s%ls%s%ls%s%ls%s%ls%s%ls%s%ls ",
656				wdss, wds.names[6], wdss, wds.names[0],
657				wdss, wds.names[1], wdss, wds.names[2],
658				wdss, wds.names[3], wdss, wds.names[4],
659				wdss, wds.names[5]);
660		}
661		printf("\n");
662
663		/* And the days of the month. */
664		for (i = 0; i != 6; i++) {
665			for (j = 0; j < count; j++)
666				printf("%-*s  ",
667				    MW(mw, year[j].extralen[i]),
668					year[j].lines[i]+1);
669			printf("\n");
670		}
671
672		m += mpl;
673	}
674}
675
676static void
677monthranger(int y, int m, int jd_flag, int before, int after)
678{
679	struct monthlines year[12];
680	struct weekdays wds;
681	char    s[MAX_WIDTH], t[MAX_WIDTH];
682	int     i, j;
683	int     mpl;
684	int     mw;
685	int	m1, m2;
686	int	prevyear = -1;
687	int	printyearheader;
688
689	mpl = jd_flag ? 3 : 4;
690	mw = jd_flag ? MONTH_WIDTH_R_J : MONTH_WIDTH_R;
691
692	while (before != 0) {
693		DECREASEMONTH(m, y);
694		before--;
695		after++;
696	}
697	m1 = y * 12 + m - 1;
698	m2 = m1 + after;
699
700	mkweekdays(&wds);
701
702	/*
703	 * The year header is printed when there are more than 'mpl' months
704	 * and if the first month is a multitude of 'mpl'.
705	 * If not, it will print the year behind every month.
706	 */
707	printyearheader = (after >= mpl - 1) && (M2M(m1) - 1) % mpl == 0;
708
709	m = m1;
710	while (m <= m2) {
711		int count = 0;
712		for (i = 0; i != mpl && m + i <= m2; i++) {
713			mkmonthr(M2Y(m + i), M2M(m + i) - 1, jd_flag, year + i);
714			count++;
715		}
716
717		/* Empty line between two rows of months. */
718		if (m != m1)
719			printf("\n");
720
721		/* Year at the top. */
722		if (printyearheader && M2Y(m) != prevyear) {
723			sprintf(s, "%d", M2Y(m));
724			printf("%s\n", center(t, s, mpl * mw));
725			prevyear = M2Y(m);
726		}
727
728		/* Month names. */
729		wprintf(L"    ");
730		for (i = 0; i < count; i++)
731			if (printyearheader)
732				wprintf(L"%-*ls", mw, year[i].name);
733			else
734				wprintf(L"%-ls %-*d", year[i].name,
735				    mw - wcslen(year[i].name) - 1, M2Y(m + i));
736		printf("\n");
737
738		/* And the days of the month. */
739		for (i = 0; i != 7; i++) {
740			/* Week day */
741			wprintf(L"%.2ls", wds.names[i]);
742
743			/* Full months */
744			for (j = 0; j < count; j++)
745				printf("%-*s",
746				    MW(mw, year[j].extralen[i]),
747					year[j].lines[i]);
748			printf("\n");
749		}
750
751		/* Week numbers. */
752		if (flag_weeks) {
753			printf("  ");
754			for (i = 0; i < count; i++)
755				printf("%-*s", mw, year[i].weeks);
756			printf("\n");
757		}
758
759		m += mpl;
760	}
761	return;
762}
763
764static void
765mkmonthr(int y, int m, int jd_flag, struct monthlines *mlines)
766{
767
768	struct tm tm;		/* for strftime printing local names of
769				 * months */
770	date    dt;		/* handy date */
771	int     dw;		/* width of numbers */
772	int     first;		/* first day of month */
773	int     firstm;		/* first day of first week of month */
774	int     i, j, k, l;	/* just indices */
775	int     last;		/* the first day of next month */
776	int     jan1 = 0;	/* the first day of this year */
777	char   *ds;		/* pointer to day strings (daystr or
778				 * jdaystr) */
779
780	/* Set name of month. */
781	memset(&tm, 0, sizeof(tm));
782	tm.tm_mon = m;
783	wcsftime(mlines->name, sizeof(mlines->name) / sizeof(mlines->name[0]),
784		 L"%OB", &tm);
785	mlines->name[0] = towupper(mlines->name[0]);
786
787	/*
788	 * Set first and last to the day number of the first day of this
789	 * month and the first day of next month respectively. Set jan1 to
790	 * the day number of the first day of this year.
791	 */
792	first = firstday(y, m + 1);
793	if (m == 11)
794		last = firstday(y + 1, 1);
795	else
796		last = firstday(y, m + 2);
797
798	if (jd_flag)
799		jan1 = firstday(y, 1);
800
801	/*
802	 * Set firstm to the day number of monday of the first week of
803	 * this month. (This might be in the last month)
804	 */
805	firstm = first - weekday(first);
806
807	/* Set ds (daystring) and dw (daywidth) according to the jd_flag. */
808	if (jd_flag) {
809		ds = jdaystr;
810		dw = 4;
811	} else {
812		ds = daystr;
813		dw = 3;
814	}
815
816	/*
817	 * Fill the lines with day of month or day of year (julian day)
818	 * line index: i, each line is one weekday. column index: j, each
819	 * column is one day number. print column index: k.
820	 */
821	for (i = 0; i != 7; i++) {
822		l = 0;
823		for (j = firstm + i, k = 0; j < last; j += 7, k += dw) {
824			if (j >= first) {
825				if (jd_flag)
826					dt.d = j - jan1 + 1;
827				else
828					sdater(j, &dt);
829				if (j == highlightdate && !flag_nohighlight
830				 && isatty(STDOUT_FILENO))
831					highlight(mlines->lines[i] + k,
832					    ds + dt.d * dw, dw, &l);
833				else
834					memcpy(mlines->lines[i] + k + l,
835					       ds + dt.d * dw, dw);
836			} else
837				memcpy(mlines->lines[i] + k + l, "    ", dw);
838		}
839		mlines->lines[i][k + l] = '\0';
840		mlines->extralen[i] = l;
841	}
842
843	/* fill the weeknumbers. */
844	if (flag_weeks) {
845		for (j = firstm, k = 0; j < last;  k += dw, j += 7)
846			if (j <= nswitch)
847				memset(mlines->weeks + k, ' ', dw);
848			else
849				memcpy(mlines->weeks + k,
850				    ds + week(j, &i)*dw, dw);
851		mlines->weeks[k] = '\0';
852	}
853}
854
855static void
856mkmonthb(int y, int m, int jd_flag, struct monthlines *mlines)
857{
858
859	struct tm tm;		/* for strftime printing local names of
860				 * months */
861	date    dt;		/* handy date */
862	int     dw;		/* width of numbers */
863	int     first;		/* first day of month */
864	int     firsts;		/* sunday of first week of month */
865	int     i, j, k, l;	/* just indices */
866	int     jan1 = 0;	/* the first day of this year */
867	int     last;		/* the first day of next month */
868	char   *ds;		/* pointer to day strings (daystr or
869				 * jdaystr) */
870
871	/* Set ds (daystring) and dw (daywidth) according to the jd_flag */
872	if (jd_flag) {
873		ds = jdaystr;
874		dw = 4;
875	} else {
876		ds = daystr;
877		dw = 3;
878	}
879
880	/* Set name of month centered. */
881	memset(&tm, 0, sizeof(tm));
882	tm.tm_mon = m;
883	wcsftime(mlines->name, sizeof(mlines->name) / sizeof(mlines->name[0]),
884		 L"%OB", &tm);
885	mlines->name[0] = towupper(mlines->name[0]);
886
887	/*
888	 * Set first and last to the day number of the first day of this
889	 * month and the first day of next month respectively. Set jan1 to
890	 * the day number of Jan 1st of this year.
891	 */
892	dt.y = y;
893	dt.m = m + 1;
894	dt.d = 1;
895	first = sndaysb(&dt);
896	if (m == 11) {
897		dt.y = y + 1;
898		dt.m = 1;
899		dt.d = 1;
900	} else {
901		dt.y = y;
902		dt.m = m + 2;
903		dt.d = 1;
904	}
905	last = sndaysb(&dt);
906
907	if (jd_flag) {
908		dt.y = y;
909		dt.m = 1;
910		dt.d = 1;
911		jan1 = sndaysb(&dt);
912	}
913
914	/*
915	 * Set firsts to the day number of sunday of the first week of
916	 * this month. (This might be in the last month)
917	 */
918	firsts = first - (weekday(first)+1) % 7;
919
920	/*
921	 * Fill the lines with day of month or day of year (Julian day)
922	 * line index: i, each line is one week. column index: j, each
923	 * column is one day number. print column index: k.
924	 */
925	for (i = 0; i != 6; i++) {
926		l = 0;
927		for (j = firsts + 7 * i, k = 0; j < last && k != dw * 7;
928		    j++, k += dw) {
929			if (j >= first) {
930				if (jd_flag)
931					dt.d = j - jan1 + 1;
932				else
933					sdateb(j, &dt);
934				if (j == highlightdate && !flag_nohighlight)
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. */
952static void
953mkweekdays(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 */
980static int
981firstday(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 */
1004static int
1005sndaysr(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 */
1021static int
1022sndaysb(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. */
1032static struct date *
1033sdater(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. */
1043static struct date *
1044sdateb(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. */
1054static char *
1055center(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. */
1065static wchar_t *
1066wcenter(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
1075static int
1076parsemonth(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
1108static void
1109highlight(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