ncal.c revision 189804 
1/*-
2 * Copyright (c) 1997 Wolfgang Helbig
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27#ifndef lint
28static const char rcsid[] =
29  "$FreeBSD: head/usr.bin/ncal/ncal.c 189804 2009-03-14 18:55:51Z das $";
30#endif /* not lint */
31
32#include <calendar.h>
33#include <ctype.h>
34#include <err.h>
35#include <langinfo.h>
36#include <locale.h>
37#include <stdio.h>
38#include <stdlib.h>
39#include <string.h>
40#include <sysexits.h>
41#include <time.h>
42#include <unistd.h>
43#include <wchar.h>
44#include <wctype.h>
45
46/* Width of one month with backward compatibility */
47#define MONTH_WIDTH_B_J 27
48#define MONTH_WIDTH_B 20
49
50#define MONTH_WIDTH_J 24
51#define MONTH_WIDTH 18
52
53#define MAX_WIDTH 28
54
55typedef struct date date;
56
57struct monthlines {
58	wchar_t name[MAX_WIDTH + 1];
59	char lines[7][MAX_WIDTH + 1];
60	char weeks[MAX_WIDTH + 1];
61};
62
63struct weekdays {
64	wchar_t names[7][4];
65};
66
67/* The switches from Julian to Gregorian in some countries */
68static struct djswitch {
69	const char *cc;	/* Country code according to ISO 3166 */
70	const char *nm;	/* Name of country */
71	date dt;	/* Last day of Julian calendar */
72} switches[] = {
73	{"AL", "Albania",       {1912, 11, 30}},
74	{"AT", "Austria",       {1583, 10,  5}},
75	{"AU", "Australia",     {1752,  9,  2}},
76	{"BE", "Belgium",       {1582, 12, 14}},
77	{"BG", "Bulgaria",      {1916,  3, 18}},
78	{"CA", "Canada",        {1752,  9,  2}},
79	{"CH", "Switzerland",   {1655,  2, 28}},
80	{"CN", "China",         {1911, 12, 18}},
81	{"CZ", "Czech Republic",{1584,  1,  6}},
82	{"DE", "Germany",       {1700,  2, 18}},
83	{"DK", "Denmark",       {1700,  2, 18}},
84	{"ES", "Spain",         {1582, 10,  4}},
85	{"FI", "Finland",       {1753,  2, 17}},
86	{"FR", "France",        {1582, 12,  9}},
87	{"GB", "United Kingdom",{1752,  9,  2}},
88	{"GR", "Greece",        {1924,  3,  9}},
89	{"HU", "Hungary",       {1587, 10, 21}},
90	{"IS", "Iceland",       {1700, 11, 16}},
91	{"IT", "Italy",         {1582, 10,  4}},
92	{"JP", "Japan",         {1918, 12, 18}},
93	{"LI", "Lithuania",     {1918,  2,  1}},
94	{"LN", "Latin",         {9999, 05, 31}},
95	{"LU", "Luxembourg",    {1582, 12, 14}},
96	{"LV", "Latvia",        {1918,  2,  1}},
97	{"NL", "Netherlands",   {1582, 12, 14}},
98	{"NO", "Norway",        {1700,  2, 18}},
99	{"PL", "Poland",        {1582, 10,  4}},
100	{"PT", "Portugal",      {1582, 10,  4}},
101	{"RO", "Romania",       {1919,  3, 31}},
102	{"RU", "Russia",        {1918,  1, 31}},
103	{"SI", "Slovenia",      {1919,  3,  4}},
104	{"SW", "Sweden",        {1753,  2, 17}},
105	{"TR", "Turkey",        {1926, 12, 18}},
106	{"US", "United States", {1752,  9,  2}},
107	{"YU", "Yugoslavia",    {1919,  3,  4}}
108};
109
110struct djswitch *dftswitch =
111    switches + sizeof(switches) / sizeof(struct djswitch) - 2;
112    /* default switch (should be "US") */
113
114/* Table used to print day of month and week numbers */
115char daystr[] = "     1  2  3  4  5  6  7  8  9 10 11 12 13 14 15"
116		" 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31"
117		" 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47"
118		" 48 49 50 51 52 53";
119
120/* Table used to print day of year and week numbers */
121char jdaystr[] = "       1   2   3   4   5   6   7   8   9"
122		 "  10  11  12  13  14  15  16  17  18  19"
123		 "  20  21  22  23  24  25  26  27  28  29"
124		 "  30  31  32  33  34  35  36  37  38  39"
125		 "  40  41  42  43  44  45  46  47  48  49"
126		 "  50  51  52  53  54  55  56  57  58  59"
127		 "  60  61  62  63  64  65  66  67  68  69"
128		 "  70  71  72  73  74  75  76  77  78  79"
129		 "  80  81  82  83  84  85  86  87  88  89"
130		 "  90  91  92  93  94  95  96  97  98  99"
131		 " 100 101 102 103 104 105 106 107 108 109"
132		 " 110 111 112 113 114 115 116 117 118 119"
133		 " 120 121 122 123 124 125 126 127 128 129"
134		 " 130 131 132 133 134 135 136 137 138 139"
135		 " 140 141 142 143 144 145 146 147 148 149"
136		 " 150 151 152 153 154 155 156 157 158 159"
137		 " 160 161 162 163 164 165 166 167 168 169"
138		 " 170 171 172 173 174 175 176 177 178 179"
139		 " 180 181 182 183 184 185 186 187 188 189"
140		 " 190 191 192 193 194 195 196 197 198 199"
141		 " 200 201 202 203 204 205 206 207 208 209"
142		 " 210 211 212 213 214 215 216 217 218 219"
143		 " 220 221 222 223 224 225 226 227 228 229"
144		 " 230 231 232 233 234 235 236 237 238 239"
145		 " 240 241 242 243 244 245 246 247 248 249"
146		 " 250 251 252 253 254 255 256 257 258 259"
147		 " 260 261 262 263 264 265 266 267 268 269"
148		 " 270 271 272 273 274 275 276 277 278 279"
149		 " 280 281 282 283 284 285 286 287 288 289"
150		 " 290 291 292 293 294 295 296 297 298 299"
151		 " 300 301 302 303 304 305 306 307 308 309"
152		 " 310 311 312 313 314 315 316 317 318 319"
153		 " 320 321 322 323 324 325 326 327 328 329"
154		 " 330 331 332 333 334 335 336 337 338 339"
155		 " 340 341 342 343 344 345 346 347 348 349"
156		 " 350 351 352 353 354 355 356 357 358 359"
157		 " 360 361 362 363 364 365 366";
158
159int     flag_weeks;		/* user wants number of week */
160int     nswitch;		/* user defined switch date */
161int	nswitchb;		/* switch date for backward compatibility */
162
163char   *center(char *s, char *t, int w);
164wchar_t *wcenter(wchar_t *s, wchar_t *t, int w);
165void	mkmonth(int year, int month, int jd_flag, struct monthlines * monthl);
166void    mkmonthb(int year, int month, int jd_flag, struct monthlines * monthl);
167void    mkweekdays(struct weekdays * wds);
168int     parsemonth(const char *s, int *m, int *y);
169void    printcc(void);
170void    printeaster(int year, int julian, int orthodox);
171void    printmonth(int year, int month, int jd_flag);
172void    printmonthb(int year, int month, int jd_flag);
173void    printyear(int year, int jd_flag);
174void    printyearb(int year, int jd_flag);
175int	firstday(int y, int m);
176date   *sdate(int ndays, struct date * d);
177date   *sdateb(int ndays, struct date * d);
178int     sndays(struct date * d);
179int     sndaysb(struct date * d);
180static void usage(void);
181int     weekdayb(int nd);
182
183int
184main(int argc, char *argv[])
185{
186	struct  djswitch *p, *q;	/* to search user defined switch date */
187	date	never = {10000, 1, 1};	/* outside valid range of dates */
188	date	ukswitch = {1752, 9, 2};/* switch date for Great Britain */
189	int     ch;			/* holds the option character */
190	int     m = 0;			/* month */
191	int	y = 0;			/* year */
192	int     flag_backward = 0;	/* user called cal--backward compat. */
193	int     flag_hole_year = 0;	/* user wants the whole year */
194	int	flag_julian_cal = 0;	/* user wants Julian Calendar */
195	int     flag_julian_day = 0;	/* user wants the Julian day
196					 * numbers */
197	int	flag_orthodox = 0;	/* use wants Orthodox easter */
198	int	flag_easter = 0;	/* use wants easter date */
199	char	*cp;			/* character pointer */
200	char	*flag_month = NULL;	/* requested month as string */
201	const char    *locale;		/* locale to get country code */
202
203	/*
204	 * Use locale to determine the country code,
205	 * and use the country code to determine the default
206	 * switchdate and date format from the switches table.
207	 */
208	if (setlocale(LC_ALL, "") == NULL)
209		warn("setlocale");
210	locale = setlocale(LC_TIME, NULL);
211	if (locale == NULL ||
212	    strcmp(locale, "C") == 0 ||
213	    strcmp(locale, "POSIX") == 0 ||
214	    strcmp(locale, "ASCII") == 0 ||
215	    strcmp(locale, "US-ASCII") == 0)
216		locale = "_US";
217	q = switches + sizeof(switches) / sizeof(struct djswitch);
218	for (p = switches; p != q; p++)
219		if ((cp = strstr(locale, p->cc)) != NULL && *(cp - 1) == '_')
220			break;
221	if (p == q) {
222		nswitch = ndaysj(&dftswitch->dt);
223	} else {
224		nswitch = ndaysj(&p->dt);
225		dftswitch = p;
226	}
227
228
229	/*
230	 * Get the filename portion of argv[0] and set flag_backward if
231	 * this program is called "cal".
232	 */
233	cp = strrchr(argv[0], '/');
234	cp = (cp == NULL) ? argv[0] : cp + 1;
235	if (strcmp("cal", cp) == 0)
236		flag_backward = 1;
237
238	/* Set the switch date to United Kingdom if backwards compatible */
239	if (flag_backward)
240		nswitchb = ndaysj(&ukswitch);
241
242	while ((ch = getopt(argc, argv, "Jejm:ops:wy")) != -1)
243		switch (ch) {
244		case 'J':
245			if (flag_backward)
246				usage();
247			nswitch = ndaysj(&never);
248			flag_julian_cal = 1;
249			break;
250		case 'e':
251			if (flag_backward)
252				usage();
253			flag_easter = 1;
254			break;
255		case 'j':
256			flag_julian_day = 1;
257			break;
258		case 'm':
259			flag_month = optarg;
260			break;
261		case 'o':
262			if (flag_backward)
263				usage();
264			flag_orthodox = 1;
265			flag_easter = 1;
266			break;
267		case 'p':
268			if (flag_backward)
269				usage();
270			printcc();
271			return (0);
272			break;
273		case 's':
274			if (flag_backward)
275				usage();
276			q = switches +
277			    sizeof(switches) / sizeof(struct djswitch);
278			for (p = switches;
279			     p != q && strcmp(p->cc, optarg) != 0; p++)
280				;
281			if (p == q)
282				errx(EX_USAGE,
283				    "%s: invalid country code", optarg);
284			nswitch = ndaysj(&(p->dt));
285			break;
286		case 'w':
287			if (flag_backward)
288				usage();
289			flag_weeks = 1;
290			break;
291		case 'y':
292			flag_hole_year = 1;
293			break;
294		default:
295			usage();
296		}
297
298	argc -= optind;
299	argv += optind;
300
301	switch (argc) {
302	case 2:
303		if (flag_easter)
304			usage();
305		flag_month = *argv++;
306		/* FALLTHROUGH */
307	case 1:
308		y = atoi(*argv++);
309		if (y < 1 || y > 9999)
310			errx(EX_USAGE, "year %d not in range 1..9999", y);
311		break;
312	case 0:
313		{
314			time_t t;
315			struct tm *tm;
316
317			t = time(NULL);
318			tm = localtime(&t);
319			y = tm->tm_year + 1900;
320			m = tm->tm_mon + 1;
321		}
322		break;
323	default:
324		usage();
325	}
326
327	if (flag_month != NULL) {
328		if (parsemonth(flag_month, &m, &y)) {
329			errx(EX_USAGE,
330			    "%s is neither a month number (1..12) nor a name",
331			    flag_month);
332		}
333	}
334
335	if (flag_easter)
336		printeaster(y, flag_julian_cal, flag_orthodox);
337	else if (argc == 1 || flag_hole_year)
338		if (flag_backward)
339			printyearb(y, flag_julian_day);
340		else
341			printyear(y, flag_julian_day);
342	else
343		if (flag_backward)
344			printmonthb(y, m, flag_julian_day);
345		else
346			printmonth(y, m, flag_julian_day);
347
348	return (0);
349}
350
351static void
352usage(void)
353{
354
355	fputs(
356	    "usage: cal [-jy] [[month] year]\n"
357	    "       cal [-j] [-m month] [year]\n"
358	    "       ncal [-Jjpwy] [-s country_code] [[month] year]\n"
359	    "       ncal [-Jeo] [year]\n", stderr);
360	exit(EX_USAGE);
361}
362
363/* print the assumed switches for all countries */
364void
365printcc(void)
366{
367	struct djswitch *p;
368	int n;	/* number of lines to print */
369	int m;	/* offset from left to right table entry on the same line */
370
371#define FSTR "%c%s %-15s%4d-%02d-%02d"
372#define DFLT(p) ((p) == dftswitch ? '*' : ' ')
373#define FSTRARG(p) DFLT(p), (p)->cc, (p)->nm, (p)->dt.y, (p)->dt.m, (p)->dt.d
374
375	n = sizeof(switches) / sizeof(struct djswitch);
376	m = (n + 1) / 2;
377	n /= 2;
378	for (p = switches; p != switches + n; p++)
379		printf(FSTR"     "FSTR"\n", FSTRARG(p), FSTRARG(p+m));
380	if (m != n)
381		printf(FSTR"\n", FSTRARG(p));
382}
383
384/* print the date of easter sunday */
385void
386printeaster(int y, int julian, int orthodox)
387{
388	date    dt;
389	struct tm tm;
390	char    buf[80];
391	static int d_first = -1;
392
393	if (d_first < 0)
394		d_first = (*nl_langinfo(D_MD_ORDER) == 'd');
395	/* force orthodox easter for years before 1583 */
396	if (y < 1583)
397		orthodox = 1;
398
399	if (orthodox)
400		if (julian)
401			easteroj(y, &dt);
402		else
403			easterog(y, &dt);
404	else
405		easterg(y, &dt);
406
407	memset(&tm, 0, sizeof(tm));
408	tm.tm_year = dt.y - 1900;
409	tm.tm_mon  = dt.m - 1;
410	tm.tm_mday = dt.d;
411	strftime(buf, sizeof(buf), d_first ? "%e %B %Y" : "%B %e %Y",  &tm);
412	printf("%s\n", buf);
413}
414
415void
416printmonth(int y, int m, int jd_flag)
417{
418	struct monthlines month;
419	struct weekdays wds;
420	int i;
421
422	mkmonth(y, m - 1, jd_flag, &month);
423	mkweekdays(&wds);
424	printf("    %ls %d\n", month.name, y);
425	for (i = 0; i != 7; i++)
426		printf("%.2ls%s\n", wds.names[i], month.lines[i]);
427	if (flag_weeks)
428		printf("  %s\n", month.weeks);
429}
430
431void
432printmonthb(int y, int m, int jd_flag)
433{
434	struct monthlines month;
435	struct weekdays wds;
436	wchar_t s[MAX_WIDTH], t[MAX_WIDTH];
437	int i;
438	int mw;
439
440	mkmonthb(y, m - 1, jd_flag, &month);
441	mkweekdays(&wds);
442
443	mw = jd_flag ? MONTH_WIDTH_B_J : MONTH_WIDTH_B;
444
445	swprintf(s, MAX_WIDTH, L"%ls %d", month.name, y);
446	wprintf(L"%ls\n", wcenter(t, s, mw));
447
448	if (jd_flag)
449		wprintf(L" %ls %ls %ls %ls %ls %ls %.2ls\n",
450			wds.names[6], wds.names[0],
451			wds.names[1], wds.names[2], wds.names[3],
452			wds.names[4], wds.names[5]);
453	else
454		wprintf(L"%ls%ls%ls%ls%ls%ls%.2ls\n", wds.names[6],
455			wds.names[0], wds.names[1], wds.names[2], wds.names[3],
456			wds.names[4], wds.names[5]);
457
458	for (i = 0; i != 6; i++)
459		printf("%s\n", month.lines[i]+1);
460}
461
462void
463printyear(int y, int jd_flag)
464{
465	struct monthlines year[12];
466	struct weekdays wds;
467	char    s[80], t[80];
468	int     i, j;
469	int     mpl;
470	int     mw;
471
472	for (i = 0; i != 12; i++)
473		mkmonth(y, i, jd_flag, year + i);
474	mkweekdays(&wds);
475	mpl = jd_flag ? 3 : 4;
476	mw = jd_flag ? MONTH_WIDTH_J : MONTH_WIDTH;
477
478	sprintf(s, "%d", y);
479	printf("%s\n", center(t, s, mpl * mw));
480
481	for (j = 0; j != 12; j += mpl) {
482		printf("    %-*ls%-*ls",
483		    mw, year[j].name,
484		    mw, year[j + 1].name);
485		if (mpl == 3)
486			printf("%ls\n", year[j + 2].name);
487		else
488			printf("%-*ls%ls\n",
489		    	    mw, year[j + 2].name,
490		    	    year[j + 3].name);
491		for (i = 0; i != 7; i++) {
492			printf("%.2ls%-*s%-*s",
493			    wds.names[i],
494			    mw, year[j].lines[i],
495			    mw, year[j + 1].lines[i]);
496			if (mpl == 3)
497				printf("%s\n", year[j + 2].lines[i]);
498			else
499				printf("%-*s%s\n",
500			    	    mw, year[j + 2].lines[i],
501			    	    year[j + 3].lines[i]);
502		}
503		if (flag_weeks) {
504			if (mpl == 3)
505				printf("  %-*s%-*s%-s\n",
506				    mw, year[j].weeks,
507				    mw, year[j + 1].weeks,
508				    year[j + 2].weeks);
509			else
510				printf("  %-*s%-*s%-*s%-s\n",
511				    mw, year[j].weeks,
512				    mw, year[j + 1].weeks,
513				    mw, year[j + 2].weeks,
514				    year[j + 3].weeks);
515		}
516	}
517}
518
519void
520printyearb(int y, int jd_flag)
521{
522	struct monthlines year[12];
523	struct weekdays wds;
524	char	s[80], t[80];
525	wchar_t	ws[80], wt[80];
526	int     i, j;
527	int     mpl;
528	int     mw;
529
530	for (i = 0; i != 12; i++)
531		mkmonthb(y, i, jd_flag, year + i);
532	mkweekdays(&wds);
533	mpl = jd_flag ? 2 : 3;
534	mw = jd_flag ? MONTH_WIDTH_B_J : MONTH_WIDTH_B;
535
536	sprintf(s, "%d", y);
537	printf("%s\n\n", center(t, s, mw * mpl + mpl));
538
539	for (j = 0; j != 12; j += mpl) {
540		printf("%-*ls  ", mw, wcenter(ws, year[j].name, mw));
541		if (mpl == 2)
542			printf("%ls\n", wcenter(ws, year[j + 1].name, mw));
543		else
544			printf("%-*ls  %ls\n", mw,
545			    wcenter(ws, year[j + 1].name, mw),
546			    wcenter(wt, year[j + 2].name, mw));
547
548		if (mpl == 2)
549			wprintf(L" %ls %ls %ls %ls %ls %ls %ls "
550				" %ls %ls %ls %ls %ls %ls %.2ls\n",
551				wds.names[6], wds.names[0], wds.names[1],
552				wds.names[2], wds.names[3], wds.names[4],
553				wds.names[5],
554				wds.names[6], wds.names[0], wds.names[1],
555				wds.names[2], wds.names[3], wds.names[4],
556				wds.names[5]);
557		else
558			wprintf(L"%ls%ls%ls%ls%ls%ls%ls "
559				"%ls%ls%ls%ls%ls%ls%ls "
560				"%ls%ls%ls%ls%ls%ls%.2ls\n",
561				wds.names[6], wds.names[0], wds.names[1],
562				wds.names[2], wds.names[3], wds.names[4],
563				wds.names[5],
564				wds.names[6], wds.names[0], wds.names[1],
565				wds.names[2], wds.names[3], wds.names[4],
566				wds.names[5],
567				wds.names[6], wds.names[0], wds.names[1],
568				wds.names[2], wds.names[3], wds.names[4],
569				wds.names[5]);
570		for (i = 0; i != 6; i++) {
571			if (mpl == 2)
572				printf("%-*s  %s\n",
573			    mw, year[j].lines[i]+1,
574			    year[j + 1].lines[i]+1);
575			else
576				printf("%-*s  %-*s  %s\n",
577			    mw, year[j].lines[i]+1,
578			    mw, year[j + 1].lines[i]+1,
579			    year[j + 2].lines[i]+1);
580
581		}
582	}
583}
584
585void
586mkmonth(int y, int m, int jd_flag, struct monthlines *mlines)
587{
588
589	struct tm tm;		/* for strftime printing local names of
590				 * months */
591	date    dt;		/* handy date */
592	int     dw;		/* width of numbers */
593	int     first;		/* first day of month */
594	int     firstm;		/* first day of first week of month */
595	int     i, j, k;	/* just indices */
596	int     last;		/* the first day of next month */
597	int     jan1 = 0;	/* the first day of this year */
598	char   *ds;		/* pointer to day strings (daystr or
599				 * jdaystr) */
600
601	/* Set name of month. */
602	memset(&tm, 0, sizeof(tm));
603	tm.tm_mon = m;
604	wcsftime(mlines->name, sizeof(mlines->name) / sizeof(mlines->name[0]),
605		 L"%OB", &tm);
606	mlines->name[0] = towupper(mlines->name[0]);
607
608	/*
609	 * Set first and last to the day number of the first day of this
610	 * month and the first day of next month respectively. Set jan1 to
611	 * the day number of the first day of this year.
612	 */
613	first = firstday(y, m + 1);
614	if (m == 11)
615		last = firstday(y + 1, 1);
616	else
617		last = firstday(y, m + 2);
618
619	if (jd_flag)
620		jan1 = firstday(y, 1);
621
622	/*
623	 * Set firstm to the day number of monday of the first week of
624	 * this month. (This might be in the last month)
625	 */
626	firstm = first - weekday(first);
627
628	/* Set ds (daystring) and dw (daywidth) according to the jd_flag */
629	if (jd_flag) {
630		ds = jdaystr;
631		dw = 4;
632	} else {
633		ds = daystr;
634		dw = 3;
635	}
636
637	/*
638	 * Fill the lines with day of month or day of year (julian day)
639	 * line index: i, each line is one weekday. column index: j, each
640	 * column is one day number. print column index: k.
641	 */
642	for (i = 0; i != 7; i++) {
643		for (j = firstm + i, k = 0; j < last; j += 7, k += dw)
644			if (j >= first) {
645				if (jd_flag)
646					dt.d = j - jan1 + 1;
647				else
648					sdate(j, &dt);
649				memcpy(mlines->lines[i] + k,
650				       ds + dt.d * dw, dw);
651			} else
652				memcpy(mlines->lines[i] + k, "    ", dw);
653		mlines->lines[i][k] = '\0';
654
655	}
656
657	/* fill the weeknumbers */
658	if (flag_weeks) {
659		for (j = firstm, k = 0; j < last;  k += dw, j += 7)
660			if (j <= nswitch)
661				memset(mlines->weeks + k, ' ', dw);
662			else
663				memcpy(mlines->weeks + k,
664				    ds + week(j, &i)*dw, dw);
665		mlines->weeks[k] = '\0';
666	}
667}
668
669void
670mkmonthb(int y, int m, int jd_flag, struct monthlines *mlines)
671{
672
673	struct tm tm;		/* for strftime printing local names of
674				 * months */
675	date    dt;		/* handy date */
676	int     dw;		/* width of numbers */
677	int     first;		/* first day of month */
678	int     firsts;		/* sunday of first week of month */
679	int     i, j, k;	/* just indices */
680	int     jan1 = 0;	/* the first day of this year */
681	int     last;		/* the first day of next month */
682	char   *ds;		/* pointer to day strings (daystr or
683				 * jdaystr) */
684
685	/* Set ds (daystring) and dw (daywidth) according to the jd_flag */
686	if (jd_flag) {
687		ds = jdaystr;
688		dw = 4;
689	} else {
690		ds = daystr;
691		dw = 3;
692	}
693
694	/* Set name of month centered */
695	memset(&tm, 0, sizeof(tm));
696	tm.tm_mon = m;
697	wcsftime(mlines->name, sizeof(mlines->name) / sizeof(mlines->name[0]),
698		 L"%OB", &tm);
699	mlines->name[0] = towupper(mlines->name[0]);
700
701	/*
702	 * Set first and last to the day number of the first day of this
703	 * month and the first day of next month respectively. Set jan1 to
704	 * the day number of Jan 1st of this year.
705	 */
706	dt.y = y;
707	dt.m = m + 1;
708	dt.d = 1;
709	first = sndaysb(&dt);
710	if (m == 11) {
711		dt.y = y + 1;
712		dt.m = 1;
713		dt.d = 1;
714	} else {
715		dt.y = y;
716		dt.m = m + 2;
717		dt.d = 1;
718	}
719	last = sndaysb(&dt);
720
721	if (jd_flag) {
722		dt.y = y;
723		dt.m = 1;
724		dt.d = 1;
725		jan1 = sndaysb(&dt);
726	}
727
728	/*
729	 * Set firsts to the day number of sunday of the first week of
730	 * this month. (This might be in the last month)
731	 */
732	firsts = first - (weekday(first)+1) % 7;
733
734	/*
735	 * Fill the lines with day of month or day of year (Julian day)
736	 * line index: i, each line is one week. column index: j, each
737	 * column is one day number. print column index: k.
738	 */
739	for (i = 0; i != 6; i++) {
740		for (j = firsts + 7 * i, k = 0; j < last && k != dw * 7;
741		     j++, k += dw)
742			if (j >= first) {
743				if (jd_flag)
744					dt.d = j - jan1 + 1;
745				else
746					sdateb(j, &dt);
747				memcpy(mlines->lines[i] + k,
748				       ds + dt.d * dw, dw);
749			} else
750				memcpy(mlines->lines[i] + k, "    ", dw);
751		if (k == 0)
752			mlines->lines[i][1] = '\0';
753		else
754			mlines->lines[i][k] = '\0';
755	}
756}
757
758/* Put the local names of weekdays into the wds */
759void
760mkweekdays(struct weekdays *wds)
761{
762	int i, len;
763	struct tm tm;
764	wchar_t buf[20];
765
766	memset(&tm, 0, sizeof(tm));
767
768	for (i = 0; i != 7; i++) {
769		tm.tm_wday = (i+1) % 7;
770		wcsftime(buf, sizeof(buf), L"%a", &tm);
771		len = wcslen(buf);
772		if (len > 2)
773			len = 2;
774		wcscpy(wds->names[i], L"   ");
775		wcsncpy(wds->names[i] + 2 - len, buf, len);
776	}
777}
778
779/*
780 * Compute the day number of the first
781 * existing date after the first day in month.
782 * (the first day in month and even the month might not exist!)
783 */
784int
785firstday(int y, int m)
786{
787	date dt;
788	int nd;
789
790	dt.y = y;
791	dt.m = m;
792	dt.d = 1;
793	nd = sndays(&dt);
794	for (;;) {
795		sdate(nd, &dt);
796		if ((dt.m >= m && dt.y == y) || dt.y > y)
797			return (nd);
798		else
799			nd++;
800	}
801	/* NEVER REACHED */
802}
803
804/*
805 * Compute the number of days from date, obey the local switch from
806 * Julian to Gregorian if specified by the user.
807 */
808int
809sndays(struct date *d)
810{
811
812	if (nswitch != 0)
813		if (nswitch < ndaysj(d))
814			return (ndaysg(d));
815		else
816			return (ndaysj(d));
817	else
818		return ndaysg(d);
819}
820
821/*
822 * Compute the number of days from date, obey the switch from
823 * Julian to Gregorian as used by UK and her colonies.
824 */
825int
826sndaysb(struct date *d)
827{
828
829	if (nswitchb < ndaysj(d))
830		return (ndaysg(d));
831	else
832		return (ndaysj(d));
833}
834
835/* Inverse of sndays */
836struct date *
837sdate(int nd, struct date *d)
838{
839
840	if (nswitch < nd)
841		return (gdate(nd, d));
842	else
843		return (jdate(nd, d));
844}
845
846/* Inverse of sndaysb */
847struct date *
848sdateb(int nd, struct date *d)
849{
850
851	if (nswitchb < nd)
852		return (gdate(nd, d));
853	else
854		return (jdate(nd, d));
855}
856
857/* Center string t in string s of length w by putting enough leading blanks */
858char *
859center(char *s, char *t, int w)
860{
861	char blanks[80];
862
863	memset(blanks, ' ', sizeof(blanks));
864	sprintf(s, "%.*s%s", (int)(w - strlen(t)) / 2, blanks, t);
865	return (s);
866}
867
868/* Center string t in string s of length w by putting enough leading blanks */
869wchar_t *
870wcenter(wchar_t *s, wchar_t *t, int w)
871{
872	char blanks[80];
873
874	memset(blanks, ' ', sizeof(blanks));
875	swprintf(s, MAX_WIDTH, L"%.*s%ls", (int)(w - wcslen(t)) / 2, blanks, t);
876	return (s);
877}
878
879int
880parsemonth(const char *s, int *m, int *y)
881{
882	int nm, ny;
883	char *cp;
884	struct tm tm;
885
886	nm = (int)strtol(s, &cp, 10);
887	if (cp != s) {
888		ny = *y;
889		if (*cp == '\0') {
890			;	/* no special action */
891		} else if (*cp == 'f' || *cp == 'F') {
892			if (nm <= *m)
893				ny++;
894		} else if (*cp == 'p' || *cp == 'P') {
895			if (nm >= *m)
896				ny--;
897		} else
898			return (1);
899		if (nm < 1 || nm > 12)
900			return 1;
901		*m = nm;
902		*y = ny;
903		return (0);
904	}
905	if (strptime(s, "%B", &tm) != NULL || strptime(s, "%b", &tm) != NULL) {
906		*m = tm.tm_mon + 1;
907		return (0);
908	}
909	return (1);
910}
911