xref: /freebsd/usr.bin/calendar/day.c (revision 39beb93c3f8bdbf72a61fda42300b5ebed7390c8)
1 /*
2  * Copyright (c) 1989, 1993, 1994
3  *	The Regents of the University of California.  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  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
36 
37 #include <sys/types.h>
38 #include <sys/uio.h>
39 #include <ctype.h>
40 #include <err.h>
41 #include <locale.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <time.h>
46 
47 #include "pathnames.h"
48 #include "calendar.h"
49 
50 struct tm		*tp;
51 static const struct tm	tm0;
52 int			*cumdays, yrdays;
53 char			dayname[10];
54 
55 
56 /* 1-based month, 0-based days, cumulative */
57 int	daytab[][14] = {
58 	{0, -1, 30, 58, 89, 119, 150, 180, 211, 242, 272, 303, 333, 364},
59 	{0, -1, 30, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365},
60 };
61 
62 static char const *days[] = {
63 	"sun", "mon", "tue", "wed", "thu", "fri", "sat", NULL,
64 };
65 
66 static const char *months[] = {
67 	"jan", "feb", "mar", "apr", "may", "jun",
68 	"jul", "aug", "sep", "oct", "nov", "dec", NULL,
69 };
70 
71 static struct fixs fndays[8];		/* full national days names */
72 static struct fixs ndays[8];		/* short national days names */
73 
74 static struct fixs fnmonths[13];	/* full national months names */
75 static struct fixs nmonths[13];		/* short national month names */
76 
77 
78 void
79 setnnames(void)
80 {
81 	char buf[80];
82 	int i, l;
83 	struct tm tm;
84 
85 	for (i = 0; i < 7; i++) {
86 		tm.tm_wday = i;
87 		strftime(buf, sizeof(buf), "%a", &tm);
88 		for (l = strlen(buf);
89 		     l > 0 && isspace((unsigned char)buf[l - 1]);
90 		     l--)
91 			;
92 		buf[l] = '\0';
93 		if (ndays[i].name != NULL)
94 			free(ndays[i].name);
95 		if ((ndays[i].name = strdup(buf)) == NULL)
96 			errx(1, "cannot allocate memory");
97 		ndays[i].len = strlen(buf);
98 
99 		strftime(buf, sizeof(buf), "%A", &tm);
100 		for (l = strlen(buf);
101 		     l > 0 && isspace((unsigned char)buf[l - 1]);
102 		     l--)
103 			;
104 		buf[l] = '\0';
105 		if (fndays[i].name != NULL)
106 			free(fndays[i].name);
107 		if ((fndays[i].name = strdup(buf)) == NULL)
108 			errx(1, "cannot allocate memory");
109 		fndays[i].len = strlen(buf);
110 	}
111 
112 	for (i = 0; i < 12; i++) {
113 		tm.tm_mon = i;
114 		strftime(buf, sizeof(buf), "%b", &tm);
115 		for (l = strlen(buf);
116 		     l > 0 && isspace((unsigned char)buf[l - 1]);
117 		     l--)
118 			;
119 		buf[l] = '\0';
120 		if (nmonths[i].name != NULL)
121 			free(nmonths[i].name);
122 		if ((nmonths[i].name = strdup(buf)) == NULL)
123 			errx(1, "cannot allocate memory");
124 		nmonths[i].len = strlen(buf);
125 
126 		strftime(buf, sizeof(buf), "%B", &tm);
127 		for (l = strlen(buf);
128 		     l > 0 && isspace((unsigned char)buf[l - 1]);
129 		     l--)
130 			;
131 		buf[l] = '\0';
132 		if (fnmonths[i].name != NULL)
133 			free(fnmonths[i].name);
134 		if ((fnmonths[i].name = strdup(buf)) == NULL)
135 			errx(1, "cannot allocate memory");
136 		fnmonths[i].len = strlen(buf);
137 	}
138 }
139 
140 void
141 settime(time_t now)
142 {
143 	char *oldl, *lbufp;
144 
145 	tp = localtime(&now);
146 	if (isleap(tp->tm_year + 1900)) {
147 		yrdays = 366;
148 		cumdays = daytab[1];
149 	} else {
150 		yrdays = 365;
151 		cumdays = daytab[0];
152 	}
153 	/* Friday displays Monday's events */
154 	if (f_dayAfter == 0 && f_dayBefore == 0 && Friday != -1)
155 		f_dayAfter = tp->tm_wday == Friday ? 3 : 1;
156 	header[5].iov_base = dayname;
157 
158 	oldl = NULL;
159 	lbufp = setlocale(LC_TIME, NULL);
160 	if (lbufp != NULL && (oldl = strdup(lbufp)) == NULL)
161 		errx(1, "cannot allocate memory");
162 	(void)setlocale(LC_TIME, "C");
163 	header[5].iov_len = strftime(dayname, sizeof(dayname), "%A", tp);
164 	(void)setlocale(LC_TIME, (oldl != NULL ? oldl : ""));
165 	if (oldl != NULL)
166 		free(oldl);
167 
168 	setnnames();
169 }
170 
171 /* convert Day[/Month][/Year] into unix time (since 1970)
172  * Day: two digits, Month: two digits, Year: digits
173  */
174 time_t
175 Mktime(char *dp)
176 {
177 	time_t t;
178 	int d, m, y;
179 	struct tm tm;
180 
181 	(void)time(&t);
182 	tp = localtime(&t);
183 
184 	tm = tm0;
185 	tm.tm_mday = tp->tm_mday;
186 	tm.tm_mon = tp->tm_mon;
187 	tm.tm_year = tp->tm_year;
188 
189 	switch (sscanf(dp, "%d.%d.%d", &d, &m, &y)) {
190 	case 3:
191 		if (y > 1900)
192 			y -= 1900;
193 		tm.tm_year = y;
194 		/* FALLTHROUGH */
195 	case 2:
196 		tm.tm_mon = m - 1;
197 		/* FALLTHROUGH */
198 	case 1:
199 		tm.tm_mday = d;
200 	}
201 
202 #ifdef DEBUG
203 	fprintf(stderr, "Mktime: %d %d %s\n",
204 	    (int)mktime(&tm), (int)t, asctime(&tm));
205 #endif
206 	return (mktime(&tm));
207 }
208 
209 /*
210  * Possible date formats include any combination of:
211  *	3-charmonth			(January, Jan, Jan)
212  *	3-charweekday			(Friday, Monday, mon.)
213  *	numeric month or day		(1, 2, 04)
214  *
215  * Any character may separate them, or they may not be separated.  Any line,
216  * following a line that is matched, that starts with "whitespace", is shown
217  * along with the matched line.
218  */
219 int
220 isnow(char *endp, int *monthp, int *dayp, int *varp)
221 {
222 	int day, flags, month = 0, v1, v2;
223 
224 	/*
225 	 * CONVENTION
226 	 *
227 	 * Month:     1-12
228 	 * Monthname: Jan .. Dec
229 	 * Day:       1-31
230 	 * Weekday:   Mon-Sun
231 	 *
232 	 */
233 
234 	flags = 0;
235 
236 	/* read first field */
237 	/* didn't recognize anything, skip it */
238 	if (!(v1 = getfield(endp, &endp, &flags)))
239 		return (0);
240 
241 	/* Easter or Easter depending days */
242 	if (flags & F_EASTER)
243 		day = v1 - 1; /* days since January 1 [0-365] */
244 
245 	 /*
246 	  * 1. {Weekday,Day} XYZ ...
247 	  *
248 	  *    where Day is > 12
249 	  */
250 	else if (flags & F_ISDAY || v1 > 12) {
251 
252 		/* found a day; day: 1-31 or weekday: 1-7 */
253 		day = v1;
254 
255 		/* {Day,Weekday} {Month,Monthname} ... */
256 		/* if no recognizable month, assume just a day alone
257 		 * in other words, find month or use current month */
258 		if (!(month = getfield(endp, &endp, &flags)))
259 			month = tp->tm_mon + 1;
260 	}
261 
262 	/* 2. {Monthname} XYZ ... */
263 	else if (flags & F_ISMONTH) {
264 		month = v1;
265 
266 		/* Monthname {day,weekday} */
267 		/* if no recognizable day, assume the first day in month */
268 		if (!(day = getfield(endp, &endp, &flags)))
269 			day = 1;
270 	}
271 
272 	/* Hm ... */
273 	else {
274 		v2 = getfield(endp, &endp, &flags);
275 
276 		/*
277 		 * {Day} {Monthname} ...
278 		 * where Day <= 12
279 		 */
280 		if (flags & F_ISMONTH) {
281 			day = v1;
282 			month = v2;
283 			*varp = 0;
284 		}
285 
286 		/* {Month} {Weekday,Day} ...  */
287 		else {
288 			/* F_ISDAY set, v2 > 12, or no way to tell */
289 			month = v1;
290 			/* if no recognizable day, assume the first */
291 			day = v2 ? v2 : 1;
292 			*varp = 0;
293 		}
294 	}
295 
296 	/* convert Weekday into *next*  Day,
297 	 * e.g.: 'Sunday' -> 22
298 	 *       'SundayLast' -> ??
299 	 */
300 	if (flags & F_ISDAY) {
301 #ifdef DEBUG
302 		fprintf(stderr, "\nday: %d %s month %d\n", day, endp, month);
303 #endif
304 
305 		*varp = 1;
306 		/* variable weekday, SundayLast, MondayFirst ... */
307 		if (day < 0 || day >= 10) {
308 
309 			/* negative offset; last, -4 .. -1 */
310 			if (day < 0) {
311 				v1 = day / 10 - 1;	/* offset -4 ... -1 */
312 				day = 10 + (day % 10);	/* day 1 ... 7 */
313 
314 				/* day, eg '22nd' */
315 				v2 = tp->tm_mday +
316 				    (((day - 1) - tp->tm_wday + 7) % 7);
317 
318 				/* (month length - day)	/ 7 + 1 */
319 				if (cumdays[month + 1] - cumdays[month] >= v2
320 				    && ((int)((cumdays[month + 1] -
321 				    cumdays[month] - v2) / 7) + 1) == -v1)
322 					day = v2;	/* bingo ! */
323 
324 				/* set to yesterday */
325 				else {
326 					day = tp->tm_mday - 1;
327 					if (day == 0)
328 						return (0);
329 				}
330 			}
331 
332 			/* first, second ... +1 ... +5 */
333 			else {
334 				/* offset: +1 (first Sunday) ... */
335 				v1 = day / 10;
336 				day = day % 10;
337 
338 				/* day, eg '22th' */
339 				v2 = tp->tm_mday +
340 				    (((day - 1) - tp->tm_wday + 7) % 7);
341 
342 				/* Hurrah! matched */
343 				if (((v2 - 1 + 7) / 7) == v1 )
344 					day = v2;
345 
346 				else {
347 					/* set to yesterday */
348 					day = tp->tm_mday - 1;
349 					if (day == 0)
350 						return (0);
351 				}
352 			}
353 		} else {
354 			/* wired */
355 			day = tp->tm_mday + (((day - 1) - tp->tm_wday + 7) % 7);
356 			*varp = 1;
357 		}
358 	}
359 
360 	if (!(flags & F_EASTER)) {
361 		if (day + cumdays[month] > cumdays[month + 1]) {
362 			/* off end of month, adjust */
363 			day -= (cumdays[month + 1] - cumdays[month]);
364 			/* next year */
365 			if (++month > 12)
366 				month = 1;
367 		}
368 		*monthp = month;
369 		*dayp = day;
370 		day = cumdays[month] + day;
371 	} else {
372 		for (v1 = 0; day > cumdays[v1]; v1++)
373 			;
374 		*monthp = v1 - 1;
375 		*dayp = day - cumdays[v1 - 1];
376 		*varp = 1;
377 	}
378 
379 #ifdef DEBUG
380 	fprintf(stderr, "day2: day %d(%d-%d) yday %d\n",
381 	    *dayp, day, cumdays[month], tp->tm_yday);
382 #endif
383 
384 	/* When days before or days after is specified */
385 	/* no year rollover */
386 	if (day >= tp->tm_yday - f_dayBefore &&
387 	    day <= tp->tm_yday + f_dayAfter)
388 		return (1);
389 
390 	/* next year */
391 	if (tp->tm_yday + f_dayAfter >= yrdays) {
392 		int end = tp->tm_yday + f_dayAfter - yrdays;
393 		if (day <= end)
394 			return (1);
395 	}
396 
397 	/* previous year */
398 	if (tp->tm_yday - f_dayBefore < 0) {
399 		int before = yrdays + (tp->tm_yday - f_dayBefore);
400 		if (day >= before)
401 			return (1);
402 	}
403 
404 	return (0);
405 }
406 
407 
408 int
409 getmonth(char *s)
410 {
411 	const char **p;
412 	struct fixs *n;
413 
414 	for (n = fnmonths; n->name; ++n)
415 		if (!strncasecmp(s, n->name, n->len))
416 			return ((n - fnmonths) + 1);
417 	for (n = nmonths; n->name; ++n)
418 		if (!strncasecmp(s, n->name, n->len))
419 			return ((n - nmonths) + 1);
420 	for (p = months; *p; ++p)
421 		if (!strncasecmp(s, *p, 3))
422 			return ((p - months) + 1);
423 	return (0);
424 }
425 
426 
427 int
428 getday(char *s)
429 {
430 	const char **p;
431 	struct fixs *n;
432 
433 	for (n = fndays; n->name; ++n)
434 		if (!strncasecmp(s, n->name, n->len))
435 			return ((n - fndays) + 1);
436 	for (n = ndays; n->name; ++n)
437 		if (!strncasecmp(s, n->name, n->len))
438 			return ((n - ndays) + 1);
439 	for (p = days; *p; ++p)
440 		if (!strncasecmp(s, *p, 3))
441 			return ((p - days) + 1);
442 	return (0);
443 }
444 
445 /* return offset for variable weekdays
446  * -1 -> last weekday in month
447  * +1 -> first weekday in month
448  * ... etc ...
449  */
450 int
451 getdayvar(char *s)
452 {
453 	int offs;
454 
455 	offs = strlen(s);
456 
457 	/* Sun+1 or Wednesday-2
458 	 *    ^              ^   */
459 
460 	/* fprintf(stderr, "x: %s %s %d\n", s, s + offs - 2, offs); */
461 	switch (*(s + offs - 2)) {
462 	case '-':
463 		return (-(atoi(s + offs - 1)));
464 	case '+':
465 		return (atoi(s + offs - 1));
466 	}
467 
468 	/*
469 	 * some aliases: last, first, second, third, fourth
470 	 */
471 
472 	/* last */
473 	if      (offs > 4 && !strcasecmp(s + offs - 4, "last"))
474 		return (-1);
475 	else if (offs > 5 && !strcasecmp(s + offs - 5, "first"))
476 		return (+1);
477 	else if (offs > 6 && !strcasecmp(s + offs - 6, "second"))
478 		return (+2);
479 	else if (offs > 5 && !strcasecmp(s + offs - 5, "third"))
480 		return (+3);
481 	else if (offs > 6 && !strcasecmp(s + offs - 6, "fourth"))
482 		return (+4);
483 
484 	/* no offset detected */
485 	return (0);
486 }
487