cal.c revision 1.3 1 /*
2 * Copyright (c) 1989 The Regents of the University of California.
3 * All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Kim Letkeman.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 * 3. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37 #ifndef lint
38 char copyright[] =
39 "@(#) Copyright (c) 1989 The Regents of the University of California.\n\
40 All rights reserved.\n";
41 #endif /* not lint */
42
43 #ifndef lint
44 /*static char sccsid[] = "from: @(#)cal.c 5.2 (Berkeley) 4/19/91";*/
45 static char rcsid[] = "$Id: cal.c,v 1.3 1994/01/25 00:49:35 cgd Exp $";
46 #endif /* not lint */
47
48 #include <sys/types.h>
49 #include <sys/time.h>
50 #include <stdio.h>
51 #include <ctype.h>
52
53 #define THURSDAY 4 /* for reformation */
54 #define SATURDAY 6 /* 1 Jan 1 was a Saturday */
55
56 #define FIRST_MISSING_DAY 639787 /* 3 Sep 1752 */
57 #define NUMBER_MISSING_DAYS 11 /* 11 day correction */
58
59 #define MAXDAYS 42 /* max slots in a month array */
60 #define SPACE -1 /* used in day array */
61
62 static int days_in_month[2][13] = {
63 {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
64 {0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
65 };
66
67 int sep1752[MAXDAYS] = {
68 SPACE, SPACE, 1, 2, 14, 15, 16,
69 17, 18, 19, 20, 21, 22, 23,
70 24, 25, 26, 27, 28, 29, 30,
71 SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
72 SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
73 SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
74 }, j_sep1752[MAXDAYS] = {
75 SPACE, SPACE, 245, 246, 258, 259, 260,
76 261, 262, 263, 264, 265, 266, 267,
77 268, 269, 270, 271, 272, 273, 274,
78 SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
79 SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
80 SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
81 }, empty[MAXDAYS] = {
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 SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
86 SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
87 SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
88 };
89
90 char *month_names[12] = {
91 "January", "February", "March", "April", "May", "June",
92 "July", "August", "September", "October", "November", "December",
93 };
94
95 char *day_headings = " S M Tu W Th F S";
96 char *j_day_headings = " S M Tu W Th F S";
97
98 /* leap year -- account for gregorian reformation in 1752 */
99 #define leap_year(yr) \
100 ((yr) <= 1752 ? !((yr) % 4) : \
101 !((yr) % 4) && ((yr) % 100) || !((yr) % 400))
102
103 /* number of centuries since 1700, not inclusive */
104 #define centuries_since_1700(yr) \
105 ((yr) > 1700 ? (yr) / 100 - 17 : 0)
106
107 /* number of centuries since 1700 whose modulo of 400 is 0 */
108 #define quad_centuries_since_1700(yr) \
109 ((yr) > 1600 ? ((yr) - 1600) / 400 : 0)
110
111 /* number of leap years between year 1 and this year, not inclusive */
112 #define leap_years_since_year_1(yr) \
113 ((yr) / 4 - centuries_since_1700(yr) + quad_centuries_since_1700(yr))
114
115 int julian;
116
117 main(argc, argv)
118 int argc;
119 char **argv;
120 {
121 extern char *optarg;
122 extern int optind;
123 struct tm *local_time;
124 time_t now, time();
125 int ch, month, year, yflag;
126
127 yflag = 0;
128 while ((ch = getopt(argc, argv, "jy")) != EOF)
129 switch(ch) {
130 case 'j':
131 julian = 1;
132 break;
133 case 'y':
134 yflag = 1;
135 break;
136 case '?':
137 default:
138 usage();
139 }
140 argc -= optind;
141 argv += optind;
142
143 month = 0;
144 switch(argc) {
145 case 2:
146 if ((month = atoi(*argv++)) <= 0 || month > 12) {
147 (void)fprintf(stderr,
148 "cal: illegal month value: use 0-12\n");
149 exit(1);
150 }
151 /* FALLTHROUGH */
152 case 1:
153 if ((year = atoi(*argv)) <= 0 || year > 9999) {
154 (void)fprintf(stderr,
155 "cal: illegal year value: use 0-9999\n");
156 exit(1);
157 }
158 break;
159 case 0:
160 (void)time(&now);
161 local_time = localtime(&now);
162 year = local_time->tm_year + 1900;
163 if (!yflag)
164 month = local_time->tm_mon + 1;
165 break;
166 default:
167 usage();
168 }
169
170 if (month)
171 monthly(month, year);
172 else if (julian)
173 j_yearly(year);
174 else
175 yearly(year);
176 exit(0);
177 }
178
179 #define DAY_LEN 3 /* 3 spaces per day */
180 #define J_DAY_LEN 4 /* 4 spaces per day */
181 #define WEEK_LEN 20 /* 7 * 3 - one space at the end */
182 #define J_WEEK_LEN 27 /* 7 * 4 - one space at the end */
183 #define HEAD_SEP 2 /* spaces between day headings */
184 #define J_HEAD_SEP 2
185
186 monthly(month, year)
187 int month, year;
188 {
189 register int col, row;
190 register char *p;
191 int len, days[MAXDAYS];
192 char lineout[30];
193
194 day_array(month, year, days);
195 len = sprintf(lineout, "%s %d", month_names[month - 1], year);
196 (void)printf("%*s%s\n%s\n",
197 ((julian ? J_WEEK_LEN : WEEK_LEN) - len) / 2, "",
198 lineout, julian ? j_day_headings : day_headings);
199 for (row = 0; row < 6; row++) {
200 for (col = 0, p = lineout; col < 7; col++,
201 p += julian ? J_DAY_LEN : DAY_LEN)
202 ascii_day(p, days[row * 7 + col]);
203 *p = '\0';
204 trim_trailing_spaces(lineout);
205 (void)printf("%s\n", lineout);
206 }
207 }
208
209 j_yearly(year)
210 int year;
211 {
212 register int col, *dp, i, month, row, which_cal;
213 register char *p;
214 int days[12][MAXDAYS];
215 char lineout[80];
216
217 (void)sprintf(lineout, "%d", year);
218 center(lineout, J_WEEK_LEN * 2 + J_HEAD_SEP, 0);
219 (void)printf("\n\n");
220 for (i = 0; i < 12; i++)
221 day_array(i + 1, year, days[i]);
222 (void)memset(lineout, ' ', sizeof(lineout) - 1);
223 lineout[sizeof(lineout) - 1] = '\0';
224 for (month = 0; month < 12; month += 2) {
225 center(month_names[month], J_WEEK_LEN, J_HEAD_SEP);
226 center(month_names[month + 1], J_WEEK_LEN, 0);
227 (void)printf("\n%s%*s%s\n", j_day_headings, J_HEAD_SEP, "",
228 j_day_headings);
229 for (row = 0; row < 6; row++) {
230 for (which_cal = 0; which_cal < 2; which_cal++) {
231 p = lineout + which_cal * (J_WEEK_LEN + 2);
232 dp = &days[month + which_cal][row * 7];
233 for (col = 0; col < 7; col++, p += J_DAY_LEN)
234 ascii_day(p, *dp++);
235 }
236 *p = '\0';
237 trim_trailing_spaces(lineout);
238 (void)printf("%s\n", lineout);
239 }
240 }
241 (void)printf("\n");
242 }
243
244 yearly(year)
245 int year;
246 {
247 register int col, *dp, i, month, row, which_cal;
248 register char *p;
249 int days[12][MAXDAYS];
250 char lineout[80];
251
252 (void)sprintf(lineout, "%d", year);
253 center(lineout, WEEK_LEN * 3 + HEAD_SEP * 2, 0);
254 (void)printf("\n\n");
255 for (i = 0; i < 12; i++)
256 day_array(i + 1, year, days[i]);
257 (void)memset(lineout, ' ', sizeof(lineout) - 1);
258 lineout[sizeof(lineout) - 1] = '\0';
259 for (month = 0; month < 12; month += 3) {
260 center(month_names[month], WEEK_LEN, HEAD_SEP);
261 center(month_names[month + 1], WEEK_LEN, HEAD_SEP);
262 center(month_names[month + 2], WEEK_LEN, 0);
263 (void)printf("\n%s%*s%s%*s%s\n", day_headings, HEAD_SEP,
264 "", day_headings, HEAD_SEP, "", day_headings);
265 for (row = 0; row < 6; row++) {
266 for (which_cal = 0; which_cal < 3; which_cal++) {
267 p = lineout + which_cal * (WEEK_LEN + 2);
268 dp = &days[month + which_cal][row * 7];
269 for (col = 0; col < 7; col++, p += DAY_LEN)
270 ascii_day(p, *dp++);
271 }
272 *p = '\0';
273 trim_trailing_spaces(lineout);
274 (void)printf("%s\n", lineout);
275 }
276 }
277 (void)printf("\n");
278 }
279
280 /*
281 * day_array --
282 * Fill in an array of 42 integers with a calendar. Assume for a moment
283 * that you took the (maximum) 6 rows in a calendar and stretched them
284 * out end to end. You would have 42 numbers or spaces. This routine
285 * builds that array for any month from Jan. 1 through Dec. 9999.
286 */
287 day_array(month, year, days)
288 register int *days;
289 int month, year;
290 {
291 register int i, day, dw, dm;
292
293 if (month == 9 && year == 1752) {
294 bcopy(julian ? j_sep1752 : sep1752,
295 days, MAXDAYS * sizeof(int));
296 return;
297 }
298 bcopy(empty, days, MAXDAYS * sizeof(int));
299 dm = days_in_month[leap_year(year)][month];
300 dw = day_in_week(1, month, year);
301 day = julian ? day_in_year(1, month, year) : 1;
302 while (dm--)
303 days[dw++] = day++;
304 }
305
306 /*
307 * day_in_year --
308 * return the 1 based day number within the year
309 */
310 day_in_year(day, month, year)
311 register int day, month;
312 int year;
313 {
314 register int i, leap;
315
316 leap = leap_year(year);
317 for (i = 1; i < month; i++)
318 day += days_in_month[leap][i];
319 return(day);
320 }
321
322 /*
323 * day_in_week
324 * return the 0 based day number for any date from 1 Jan. 1 to
325 * 31 Dec. 9999. Assumes the Gregorian reformation eliminates
326 * 3 Sep. 1752 through 13 Sep. 1752. Returns Thursday for all
327 * missing days.
328 */
329 day_in_week(day, month, year)
330 int day, month, year;
331 {
332 long temp;
333
334 temp = (long)(year - 1) * 365 + leap_years_since_year_1(year - 1)
335 + day_in_year(day, month, year);
336 if (temp < FIRST_MISSING_DAY)
337 return((temp - 1 + SATURDAY) % 7);
338 if (temp >= (FIRST_MISSING_DAY + NUMBER_MISSING_DAYS))
339 return(((temp - 1 + SATURDAY) - NUMBER_MISSING_DAYS) % 7);
340 return(THURSDAY);
341 }
342
343 ascii_day(p, day)
344 register char *p;
345 register int day;
346 {
347 register int display, val;
348 static char *aday[] = {
349 "",
350 " 1", " 2", " 3", " 4", " 5", " 6", " 7",
351 " 8", " 9", "10", "11", "12", "13", "14",
352 "15", "16", "17", "18", "19", "20", "21",
353 "22", "23", "24", "25", "26", "27", "28",
354 "29", "30", "31",
355 };
356
357 if (day == SPACE) {
358 memset(p, ' ', julian ? J_DAY_LEN : DAY_LEN);
359 return;
360 }
361 if (julian) {
362 if (val = day / 100) {
363 day %= 100;
364 *p++ = val + '0';
365 display = 1;
366 } else {
367 *p++ = ' ';
368 display = 0;
369 }
370 val = day / 10;
371 if (val || display)
372 *p++ = val + '0';
373 else
374 *p++ = ' ';
375 *p++ = day % 10 + '0';
376 } else {
377 *p++ = aday[day][0];
378 *p++ = aday[day][1];
379 }
380 *p = ' ';
381 }
382
383 trim_trailing_spaces(s)
384 register char *s;
385 {
386 register char *p;
387
388 for (p = s; *p; ++p);
389 while (p > s && isspace(*--p));
390 if (p > s)
391 ++p;
392 *p = '\0';
393 }
394
395 center(str, len, separate)
396 char *str;
397 register int len;
398 int separate;
399 {
400 len -= strlen(str);
401 (void)printf("%*s%s%*s", len / 2, "", str, len / 2 + len % 2, "");
402 if (separate)
403 (void)printf("%*s", separate, "");
404 }
405
406 usage()
407 {
408 (void)fprintf(stderr, "usage: cal [-jy] [[month] year]\n");
409 exit(1);
410 }
411