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[] = "@(#)cal.c 5.2 (Berkeley) 4/19/91";
45 #endif /* not lint */
46
47 #include <sys/types.h>
48 #include <sys/time.h>
49 #include <stdio.h>
50 #include <ctype.h>
51
52 #define THURSDAY 4 /* for reformation */
53 #define SATURDAY 6 /* 1 Jan 1 was a Saturday */
54
55 #define FIRST_MISSING_DAY 639787 /* 3 Sep 1752 */
56 #define NUMBER_MISSING_DAYS 11 /* 11 day correction */
57
58 #define MAXDAYS 42 /* max slots in a month array */
59 #define SPACE -1 /* used in day array */
60
61 static int days_in_month[2][13] = {
62 {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
63 {0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31},
64 };
65
66 int sep1752[MAXDAYS] = {
67 SPACE, SPACE, 1, 2, 14, 15, 16,
68 17, 18, 19, 20, 21, 22, 23,
69 24, 25, 26, 27, 28, 29, 30,
70 SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
71 SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
72 SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
73 }, j_sep1752[MAXDAYS] = {
74 SPACE, SPACE, 245, 246, 258, 259, 260,
75 261, 262, 263, 264, 265, 266, 267,
76 268, 269, 270, 271, 272, 273, 274,
77 SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
78 SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
79 SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
80 }, empty[MAXDAYS] = {
81 SPACE, SPACE, SPACE, SPACE, SPACE, SPACE, SPACE,
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 };
88
89 char *month_names[12] = {
90 "January", "February", "March", "April", "May", "June",
91 "July", "August", "September", "October", "November", "December",
92 };
93
94 char *day_headings = " S M Tu W Th F S";
95 char *j_day_headings = " S M Tu W Th F S";
96
97 /* leap year -- account for gregorian reformation in 1752 */
98 #define leap_year(yr) \
99 ((yr) <= 1752 ? !((yr) % 4) : \
100 !((yr) % 4) && ((yr) % 100) || !((yr) % 400))
101
102 /* number of centuries since 1700, not inclusive */
103 #define centuries_since_1700(yr) \
104 ((yr) > 1700 ? (yr) / 100 - 17 : 0)
105
106 /* number of centuries since 1700 whose modulo of 400 is 0 */
107 #define quad_centuries_since_1700(yr) \
108 ((yr) > 1600 ? ((yr) - 1600) / 400 : 0)
109
110 /* number of leap years between year 1 and this year, not inclusive */
111 #define leap_years_since_year_1(yr) \
112 ((yr) / 4 - centuries_since_1700(yr) + quad_centuries_since_1700(yr))
113
114 int julian;
115
main(argc,argv)116 main(argc, argv)
117 int argc;
118 char **argv;
119 {
120 extern char *optarg;
121 extern int optind;
122 struct tm *local_time;
123 time_t now, time();
124 int ch, month, year, yflag;
125
126 yflag = 0;
127 while ((ch = getopt(argc, argv, "jy")) != EOF)
128 switch(ch) {
129 case 'j':
130 julian = 1;
131 break;
132 case 'y':
133 yflag = 1;
134 break;
135 case '?':
136 default:
137 usage();
138 }
139 argc -= optind;
140 argv += optind;
141
142 month = 0;
143 switch(argc) {
144 case 2:
145 if ((month = atoi(*argv++)) <= 0 || month > 12) {
146 (void)fprintf(stderr,
147 "cal: illegal month value: use 0-12\n");
148 exit(1);
149 }
150 /* FALLTHROUGH */
151 case 1:
152 if ((year = atoi(*argv)) <= 0 || year > 9999) {
153 (void)fprintf(stderr,
154 "cal: illegal year value: use 0-9999\n");
155 exit(1);
156 }
157 break;
158 case 0:
159 (void)time(&now);
160 local_time = localtime(&now);
161 year = local_time->tm_year + 1900;
162 if (!yflag)
163 month = local_time->tm_mon + 1;
164 break;
165 default:
166 usage();
167 }
168
169 if (month)
170 monthly(month, year);
171 else if (julian)
172 j_yearly(year);
173 else
174 yearly(year);
175 exit(0);
176 }
177
178 #define DAY_LEN 3 /* 3 spaces per day */
179 #define J_DAY_LEN 4 /* 4 spaces per day */
180 #define WEEK_LEN 20 /* 7 * 3 - one space at the end */
181 #define J_WEEK_LEN 27 /* 7 * 4 - one space at the end */
182 #define HEAD_SEP 2 /* spaces between day headings */
183 #define J_HEAD_SEP 2
184
monthly(month,year)185 monthly(month, year)
186 int month, year;
187 {
188 register int col, row;
189 register char *p;
190 int len, days[MAXDAYS];
191 char lineout[30];
192
193 day_array(month, year, days);
194 len = sprintf(lineout, "%s %d", month_names[month - 1], year);
195 (void)printf("%*s%s\n%s\n",
196 ((julian ? J_WEEK_LEN : WEEK_LEN) - len) / 2, "",
197 lineout, julian ? j_day_headings : day_headings);
198 for (row = 0; row < 6; row++) {
199 for (col = 0, p = lineout; col < 7; col++,
200 p += julian ? J_DAY_LEN : DAY_LEN)
201 ascii_day(p, days[row * 7 + col]);
202 trim_trailing_spaces(lineout);
203 (void)printf("%s\n", lineout);
204 }
205 }
206
j_yearly(year)207 j_yearly(year)
208 int year;
209 {
210 register int col, *dp, i, month, row, which_cal;
211 register char *p;
212 int days[12][MAXDAYS];
213 char lineout[80];
214
215 (void)sprintf(lineout, "%d", year);
216 center(lineout, J_WEEK_LEN * 2 + J_HEAD_SEP, 0);
217 (void)printf("\n\n");
218 for (i = 0; i < 12; i++)
219 day_array(i + 1, year, days[i]);
220 (void)memset(lineout, ' ', sizeof(lineout) - 1);
221 lineout[sizeof(lineout) - 1] = '\0';
222 for (month = 0; month < 12; month += 2) {
223 center(month_names[month], J_WEEK_LEN, J_HEAD_SEP);
224 center(month_names[month + 1], J_WEEK_LEN, 0);
225 (void)printf("\n%s%*s%s\n", j_day_headings, J_HEAD_SEP, "",
226 j_day_headings);
227 for (row = 0; row < 6; row++) {
228 for (which_cal = 0; which_cal < 2; which_cal++) {
229 p = lineout + which_cal * (J_WEEK_LEN + 2);
230 dp = &days[month + which_cal][row * 7];
231 for (col = 0; col < 7; col++, p += J_DAY_LEN)
232 ascii_day(p, *dp++);
233 }
234 trim_trailing_spaces(lineout);
235 (void)printf("%s\n", lineout);
236 }
237 }
238 (void)printf("\n");
239 }
240
yearly(year)241 yearly(year)
242 int year;
243 {
244 register int col, *dp, i, month, row, which_cal;
245 register char *p;
246 int days[12][MAXDAYS];
247 char lineout[80];
248
249 (void)sprintf(lineout, "%d", year);
250 center(lineout, WEEK_LEN * 3 + HEAD_SEP * 2, 0);
251 (void)printf("\n\n");
252 for (i = 0; i < 12; i++)
253 day_array(i + 1, year, days[i]);
254 (void)memset(lineout, ' ', sizeof(lineout) - 1);
255 lineout[sizeof(lineout) - 1] = '\0';
256 for (month = 0; month < 12; month += 3) {
257 center(month_names[month], WEEK_LEN, HEAD_SEP);
258 center(month_names[month + 1], WEEK_LEN, HEAD_SEP);
259 center(month_names[month + 2], WEEK_LEN, 0);
260 (void)printf("\n%s%*s%s%*s%s\n", day_headings, HEAD_SEP,
261 "", day_headings, HEAD_SEP, "", day_headings);
262 for (row = 0; row < 6; row++) {
263 for (which_cal = 0; which_cal < 3; which_cal++) {
264 p = lineout + which_cal * (WEEK_LEN + 2);
265 dp = &days[month + which_cal][row * 7];
266 for (col = 0; col < 7; col++, p += DAY_LEN)
267 ascii_day(p, *dp++);
268 }
269 trim_trailing_spaces(lineout);
270 (void)printf("%s\n", lineout);
271 }
272 }
273 (void)printf("\n");
274 }
275
276 /*
277 * day_array --
278 * Fill in an array of 42 integers with a calendar. Assume for a moment
279 * that you took the (maximum) 6 rows in a calendar and stretched them
280 * out end to end. You would have 42 numbers or spaces. This routine
281 * builds that array for any month from Jan. 1 through Dec. 9999.
282 */
day_array(month,year,days)283 day_array(month, year, days)
284 register int *days;
285 int month, year;
286 {
287 register int i, day, dw, dm;
288
289 if (month == 9 && year == 1752) {
290 bcopy(julian ? j_sep1752 : sep1752,
291 days, MAXDAYS * sizeof(int));
292 return;
293 }
294 bcopy(empty, days, MAXDAYS * sizeof(int));
295 dm = days_in_month[leap_year(year)][month];
296 dw = day_in_week(1, month, year);
297 day = julian ? day_in_year(1, month, year) : 1;
298 while (dm--)
299 days[dw++] = day++;
300 }
301
302 /*
303 * day_in_year --
304 * return the 1 based day number within the year
305 */
day_in_year(day,month,year)306 day_in_year(day, month, year)
307 register int day, month;
308 int year;
309 {
310 register int i, leap;
311
312 leap = leap_year(year);
313 for (i = 1; i < month; i++)
314 day += days_in_month[leap][i];
315 return(day);
316 }
317
318 /*
319 * day_in_week
320 * return the 0 based day number for any date from 1 Jan. 1 to
321 * 31 Dec. 9999. Assumes the Gregorian reformation eliminates
322 * 3 Sep. 1752 through 13 Sep. 1752. Returns Thursday for all
323 * missing days.
324 */
day_in_week(day,month,year)325 day_in_week(day, month, year)
326 int day, month, year;
327 {
328 long temp;
329
330 temp = (long)(year - 1) * 365 + leap_years_since_year_1(year - 1)
331 + day_in_year(day, month, year);
332 if (temp < FIRST_MISSING_DAY)
333 return((temp - 1 + SATURDAY) % 7);
334 if (temp >= (FIRST_MISSING_DAY + NUMBER_MISSING_DAYS))
335 return(((temp - 1 + SATURDAY) - NUMBER_MISSING_DAYS) % 7);
336 return(THURSDAY);
337 }
338
ascii_day(p,day)339 ascii_day(p, day)
340 register char *p;
341 register int day;
342 {
343 register int display, val;
344 static char *aday[] = {
345 "",
346 " 1", " 2", " 3", " 4", " 5", " 6", " 7",
347 " 8", " 9", "10", "11", "12", "13", "14",
348 "15", "16", "17", "18", "19", "20", "21",
349 "22", "23", "24", "25", "26", "27", "28",
350 "29", "30", "31",
351 };
352
353 if (day == SPACE) {
354 memset(p, ' ', julian ? J_DAY_LEN : DAY_LEN);
355 return;
356 }
357 if (julian) {
358 if (val = day / 100) {
359 day %= 100;
360 *p++ = val + '0';
361 display = 1;
362 } else {
363 *p++ = ' ';
364 display = 0;
365 }
366 val = day / 10;
367 if (val || display)
368 *p++ = val + '0';
369 else
370 *p++ = ' ';
371 *p++ = day % 10 + '0';
372 } else {
373 *p++ = aday[day][0];
374 *p++ = aday[day][1];
375 }
376 *p = ' ';
377 }
378
trim_trailing_spaces(s)379 trim_trailing_spaces(s)
380 register char *s;
381 {
382 register char *p;
383
384 for (p = s; *p; ++p);
385 while (p > s && isspace(*--p));
386 if (p > s)
387 ++p;
388 *p = '\0';
389 }
390
center(str,len,separate)391 center(str, len, separate)
392 char *str;
393 register int len;
394 int separate;
395 {
396 len -= strlen(str);
397 (void)printf("%*s%s%*s", len / 2, "", str, len / 2 + len % 2, "");
398 if (separate)
399 (void)printf("%*s", separate, "");
400 }
401
usage()402 usage()
403 {
404 (void)fprintf(stderr, "usage: cal [-jy] [[month] year]\n");
405 exit(1);
406 }
407