xref: /netbsd/usr.bin/cal/cal.c (revision bf9ec67e)
1 /*	$NetBSD: cal.c,v 1.11 1998/11/06 22:52:18 christos Exp $	*/
2 
3 /*
4  * Copyright (c) 1989, 1993, 1994
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Kim Letkeman.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the University of
21  *	California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  */
38 
39 #include <sys/cdefs.h>
40 #ifndef lint
41 __COPYRIGHT("@(#) Copyright (c) 1989, 1993, 1994\n\
42 	The Regents of the University of California.  All rights reserved.\n");
43 #endif /* not lint */
44 
45 #ifndef lint
46 #if 0
47 static char sccsid[] = "@(#)cal.c	8.4 (Berkeley) 4/2/94";
48 #else
49 __RCSID("$NetBSD: cal.c,v 1.11 1998/11/06 22:52:18 christos Exp $");
50 #endif
51 #endif /* not lint */
52 
53 #include <sys/types.h>
54 
55 #include <ctype.h>
56 #include <err.h>
57 #include <stdio.h>
58 #include <stdlib.h>
59 #include <string.h>
60 #include <time.h>
61 #include <tzfile.h>
62 #include <unistd.h>
63 
64 #define	THURSDAY		4		/* for reformation */
65 #define	SATURDAY 		6		/* 1 Jan 1 was a Saturday */
66 
67 #define	FIRST_MISSING_DAY 	639799		/* 3 Sep 1752 */
68 #define	NUMBER_MISSING_DAYS 	11		/* 11 day correction */
69 
70 #define	MAXDAYS			42		/* max slots in a month array */
71 #define	SPACE			-1		/* used in day array */
72 
73 static int days_in_month[2][13] = {
74 	{0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
75 	{0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
76 };
77 
78 int sep1752[MAXDAYS] = {
79 	SPACE,	SPACE,	1,	2,	14,	15,	16,
80 	17,	18,	19,	20,	21,	22,	23,
81 	24,	25,	26,	27,	28,	29,	30,
82 	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
83 	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
84 	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
85 }, j_sep1752[MAXDAYS] = {
86 	SPACE,	SPACE,	245,	246,	258,	259,	260,
87 	261,	262,	263,	264,	265,	266,	267,
88 	268,	269,	270,	271,	272,	273,	274,
89 	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
90 	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
91 	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
92 }, empty[MAXDAYS] = {
93 	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
94 	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
95 	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
96 	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
97 	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
98 	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,	SPACE,
99 };
100 
101 char *month_names[12] = {
102 	"January", "February", "March", "April", "May", "June",
103 	"July", "August", "September", "October", "November", "December",
104 };
105 
106 char *day_headings = " S  M Tu  W Th  F  S";
107 char *j_day_headings = "  S   M  Tu   W  Th   F   S";
108 
109 /* leap year -- account for gregorian reformation in 1752 */
110 #define	leap_year(yr) \
111 	((yr) <= 1752 ? !((yr) % 4) : \
112 	(!((yr) % 4) && ((yr) % 100)) || !((yr) % 400))
113 
114 /* number of centuries since 1700, not inclusive */
115 #define	centuries_since_1700(yr) \
116 	((yr) > 1700 ? (yr) / 100 - 17 : 0)
117 
118 /* number of centuries since 1700 whose modulo of 400 is 0 */
119 #define	quad_centuries_since_1700(yr) \
120 	((yr) > 1600 ? ((yr) - 1600) / 400 : 0)
121 
122 /* number of leap years between year 1 and this year, not inclusive */
123 #define	leap_years_since_year_1(yr) \
124 	((yr) / 4 - centuries_since_1700(yr) + quad_centuries_since_1700(yr))
125 
126 int julian;
127 
128 void	ascii_day __P((char *, int));
129 void	center __P((char *, int, int));
130 void	day_array __P((int, int, int *));
131 int	day_in_week __P((int, int, int));
132 int	day_in_year __P((int, int, int));
133 void	j_yearly __P((int));
134 void	monthly __P((int, int));
135 int	main __P((int, char **));
136 void	trim_trailing_spaces __P((char *));
137 void	usage __P((void));
138 void	yearly __P((int));
139 
140 int
141 main(argc, argv)
142 	int argc;
143 	char **argv;
144 {
145 	struct tm *local_time;
146 	time_t now;
147 	int ch, month, year, yflag;
148 
149 	yflag = year = 0;
150 	while ((ch = getopt(argc, argv, "jy")) != -1)
151 		switch(ch) {
152 		case 'j':
153 			julian = 1;
154 			break;
155 		case 'y':
156 			yflag = 1;
157 			break;
158 		case '?':
159 		default:
160 			usage();
161 		}
162 	argc -= optind;
163 	argv += optind;
164 
165 	month = 0;
166 	switch(argc) {
167 	case 2:
168 		if ((month = atoi(*argv++)) < 1 || month > 12)
169 			errx(1, "illegal month value: use 1-12");
170 		/* FALLTHROUGH */
171 	case 1:
172 		if ((year = atoi(*argv)) < 1 || year > 9999)
173 			errx(1, "illegal year value: use 1-9999");
174 		break;
175 	case 0:
176 		(void)time(&now);
177 		local_time = localtime(&now);
178 		year = local_time->tm_year + TM_YEAR_BASE;
179 		if (!yflag)
180 			month = local_time->tm_mon + 1;
181 		break;
182 	default:
183 		usage();
184 	}
185 
186 	if (month)
187 		monthly(month, year);
188 	else if (julian)
189 		j_yearly(year);
190 	else
191 		yearly(year);
192 	exit(0);
193 }
194 
195 #define	DAY_LEN		3		/* 3 spaces per day */
196 #define	J_DAY_LEN	4		/* 4 spaces per day */
197 #define	WEEK_LEN	20		/* 7 * 3 - one space at the end */
198 #define	J_WEEK_LEN	27		/* 7 * 4 - one space at the end */
199 #define	HEAD_SEP	2		/* spaces between day headings */
200 #define	J_HEAD_SEP	2
201 
202 void
203 monthly(month, year)
204 	int month, year;
205 {
206 	int col, row, len, days[MAXDAYS];
207 	char *p, lineout[30];
208 
209 	day_array(month, year, days);
210 	len = snprintf(lineout, sizeof(lineout), "%s %d",
211 	    month_names[month - 1], year);
212 	(void)printf("%*s%s\n%s\n",
213 	    ((julian ? J_WEEK_LEN : WEEK_LEN) - len) / 2, "",
214 	    lineout, julian ? j_day_headings : day_headings);
215 	for (row = 0; row < 6; row++) {
216 		for (col = 0, p = lineout; col < 7; col++,
217 		    p += julian ? J_DAY_LEN : DAY_LEN)
218 			ascii_day(p, days[row * 7 + col]);
219 		*p = '\0';
220 		trim_trailing_spaces(lineout);
221 		(void)printf("%s\n", lineout);
222 	}
223 }
224 
225 void
226 j_yearly(year)
227 	int year;
228 {
229 	int col, *dp, i, month, row, which_cal;
230 	int days[12][MAXDAYS];
231 	char *p, lineout[80];
232 
233 	(void)snprintf(lineout, sizeof(lineout), "%d", year);
234 	center(lineout, J_WEEK_LEN * 2 + J_HEAD_SEP, 0);
235 	(void)printf("\n\n");
236 	for (i = 0; i < 12; i++)
237 		day_array(i + 1, year, days[i]);
238 	(void)memset(lineout, ' ', sizeof(lineout) - 1);
239 	lineout[sizeof(lineout) - 1] = '\0';
240 	for (month = 0; month < 12; month += 2) {
241 		center(month_names[month], J_WEEK_LEN, J_HEAD_SEP);
242 		center(month_names[month + 1], J_WEEK_LEN, 0);
243 		(void)printf("\n%s%*s%s\n", j_day_headings, J_HEAD_SEP, "",
244 		    j_day_headings);
245 		for (row = 0; row < 6; row++) {
246 			for (which_cal = 0; which_cal < 2; which_cal++) {
247 				p = lineout + which_cal * (J_WEEK_LEN + 2);
248 				dp = &days[month + which_cal][row * 7];
249 				for (col = 0; col < 7; col++, p += J_DAY_LEN)
250 					ascii_day(p, *dp++);
251 			}
252 			*p = '\0';
253 			trim_trailing_spaces(lineout);
254 			(void)printf("%s\n", lineout);
255 		}
256 	}
257 	(void)printf("\n");
258 }
259 
260 void
261 yearly(year)
262 	int year;
263 {
264 	int col, *dp, i, month, row, which_cal;
265 	int days[12][MAXDAYS];
266 	char *p, lineout[80];
267 
268 	(void)snprintf(lineout, sizeof(lineout), "%d", year);
269 	center(lineout, WEEK_LEN * 3 + HEAD_SEP * 2, 0);
270 	(void)printf("\n\n");
271 	for (i = 0; i < 12; i++)
272 		day_array(i + 1, year, days[i]);
273 	(void)memset(lineout, ' ', sizeof(lineout) - 1);
274 	lineout[sizeof(lineout) - 1] = '\0';
275 	for (month = 0; month < 12; month += 3) {
276 		center(month_names[month], WEEK_LEN, HEAD_SEP);
277 		center(month_names[month + 1], WEEK_LEN, HEAD_SEP);
278 		center(month_names[month + 2], WEEK_LEN, 0);
279 		(void)printf("\n%s%*s%s%*s%s\n", day_headings, HEAD_SEP,
280 		    "", day_headings, HEAD_SEP, "", day_headings);
281 		for (row = 0; row < 6; row++) {
282 			for (which_cal = 0; which_cal < 3; which_cal++) {
283 				p = lineout + which_cal * (WEEK_LEN + 2);
284 				dp = &days[month + which_cal][row * 7];
285 				for (col = 0; col < 7; col++, p += DAY_LEN)
286 					ascii_day(p, *dp++);
287 			}
288 			*p = '\0';
289 			trim_trailing_spaces(lineout);
290 			(void)printf("%s\n", lineout);
291 		}
292 	}
293 	(void)printf("\n");
294 }
295 
296 /*
297  * day_array --
298  *	Fill in an array of 42 integers with a calendar.  Assume for a moment
299  *	that you took the (maximum) 6 rows in a calendar and stretched them
300  *	out end to end.  You would have 42 numbers or spaces.  This routine
301  *	builds that array for any month from Jan. 1 through Dec. 9999.
302  */
303 void
304 day_array(month, year, days)
305 	int month, year;
306 	int *days;
307 {
308 	int day, dw, dm;
309 
310 	if (month == 9 && year == 1752) {
311 		memmove(days,
312 			julian ? j_sep1752 : sep1752, MAXDAYS * sizeof(int));
313 		return;
314 	}
315 	memmove(days, empty, MAXDAYS * sizeof(int));
316 	dm = days_in_month[leap_year(year)][month];
317 	dw = day_in_week(1, month, year);
318 	day = julian ? day_in_year(1, month, year) : 1;
319 	while (dm--)
320 		days[dw++] = day++;
321 }
322 
323 /*
324  * day_in_year --
325  *	return the 1 based day number within the year
326  */
327 int
328 day_in_year(day, month, year)
329 	int day, month, year;
330 {
331 	int i, leap;
332 
333 	leap = leap_year(year);
334 	for (i = 1; i < month; i++)
335 		day += days_in_month[leap][i];
336 	return (day);
337 }
338 
339 /*
340  * day_in_week
341  *	return the 0 based day number for any date from 1 Jan. 1 to
342  *	31 Dec. 9999.  Assumes the Gregorian reformation eliminates
343  *	3 Sep. 1752 through 13 Sep. 1752.  Returns Thursday for all
344  *	missing days.
345  */
346 int
347 day_in_week(day, month, year)
348 	int day, month, year;
349 {
350 	long temp;
351 
352 	temp = (long)(year - 1) * 365 + leap_years_since_year_1(year - 1)
353 	    + day_in_year(day, month, year);
354 	if (temp < FIRST_MISSING_DAY)
355 		return ((temp - 1 + SATURDAY) % 7);
356 	if (temp >= (FIRST_MISSING_DAY + NUMBER_MISSING_DAYS))
357 		return (((temp - 1 + SATURDAY) - NUMBER_MISSING_DAYS) % 7);
358 	return (THURSDAY);
359 }
360 
361 void
362 ascii_day(p, day)
363 	char *p;
364 	int day;
365 {
366 	int display, val;
367 	static char *aday[] = {
368 		"",
369 		" 1", " 2", " 3", " 4", " 5", " 6", " 7",
370 		" 8", " 9", "10", "11", "12", "13", "14",
371 		"15", "16", "17", "18", "19", "20", "21",
372 		"22", "23", "24", "25", "26", "27", "28",
373 		"29", "30", "31",
374 	};
375 
376 	if (day == SPACE) {
377 		memset(p, ' ', julian ? J_DAY_LEN : DAY_LEN);
378 		return;
379 	}
380 	if (julian) {
381 		if ((val = day / 100) != 0) {
382 			day %= 100;
383 			*p++ = val + '0';
384 			display = 1;
385 		} else {
386 			*p++ = ' ';
387 			display = 0;
388 		}
389 		val = day / 10;
390 		if (val || display)
391 			*p++ = val + '0';
392 		else
393 			*p++ = ' ';
394 		*p++ = day % 10 + '0';
395 	} else {
396 		*p++ = aday[day][0];
397 		*p++ = aday[day][1];
398 	}
399 	*p = ' ';
400 }
401 
402 void
403 trim_trailing_spaces(s)
404 	char *s;
405 {
406 	char *p;
407 
408 	for (p = s; *p; ++p)
409 		continue;
410 	while (p > s && isspace((unsigned char)*--p))
411 		continue;
412 	if (p > s)
413 		++p;
414 	*p = '\0';
415 }
416 
417 void
418 center(str, len, separate)
419 	char *str;
420 	int len;
421 	int separate;
422 {
423 
424 	len -= strlen(str);
425 	(void)printf("%*s%s%*s", len / 2, "", str, len / 2 + len % 2, "");
426 	if (separate)
427 		(void)printf("%*s", separate, "");
428 }
429 
430 void
431 usage()
432 {
433 
434 	(void)fprintf(stderr, "usage: cal [-jy] [[month] year]\n");
435 	exit(1);
436 }
437