cal.c revision 1.10 1 /* $NetBSD: cal.c,v 1.10 1998/07/28 19:26:09 mycroft 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 1.10 1998/07/28 19:26:09 mycroft 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(*--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