xref: /freebsd/usr.bin/calendar/day.c (revision 05c7a37afb48ddd5ee1bd921a5d46fe59cc70b15)
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 
35 #include <stdio.h>
36 #include <sys/types.h>
37 #include <time.h>
38 #include <sys/uio.h>
39 #include <string.h>
40 #include <stdlib.h>
41 
42 #include "pathnames.h"
43 #include "calendar.h"
44 
45 struct tm *tp;
46 int *cumdays, offset, yrdays;
47 char dayname[10];
48 
49 
50 /* 1-based month, 0-based days, cumulative */
51 int daytab[][14] = {
52 	{ 0, -1, 30, 58, 89, 119, 150, 180, 211, 242, 272, 303, 333, 364 },
53 	{ 0, -1, 30, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
54 };
55 
56 static char *days[] = {
57 	"sun", "mon", "tue", "wed", "thu", "fri", "sat", NULL,
58 };
59 
60 static char *months[] = {
61 	"jan", "feb", "mar", "apr", "may", "jun",
62 	"jul", "aug", "sep", "oct", "nov", "dec", NULL,
63 };
64 
65 
66 
67 
68 void
69 settime(now)
70     	time_t now;
71 {
72 
73 	tp = localtime(&now);
74 	if ( isleap(tp->tm_year + 1900) ) {
75 		yrdays = 366;
76 		cumdays = daytab[1];
77 	} else {
78 		yrdays = 365;
79 		cumdays = daytab[0];
80 	}
81 	/* Friday displays Monday's events */
82 	offset = tp->tm_wday == 5 ? 3 : 1;
83 	header[5].iov_base = dayname;
84 	header[5].iov_len = strftime(dayname, sizeof(dayname), "%A", tp);
85 }
86 
87 /* convert Day[/Month][/Year] into unix time (since 1970)
88  * Day: two digits, Month: two digits, Year: digits
89  */
90 time_t Mktime (date)
91     char *date;
92 {
93     time_t t;
94     int len;
95     struct tm tm;
96 
97     (void)time(&t);
98     tp = localtime(&t);
99 
100     len = strlen(date);
101     tm.tm_sec = 0;
102     tm.tm_min = 0;
103     tm.tm_hour = 0;
104     tm.tm_mday = tp->tm_mday;
105     tm.tm_mon = tp->tm_mon;
106     tm.tm_year = tp->tm_year;
107 
108 
109     /* day */
110     *(date+2) = NULL;
111     tm.tm_mday = atoi(date);
112 
113     /* month */
114     if (len >= 4) {
115 	*(date+5) = NULL;
116 	tm.tm_mon = atoi(date+3) - 1;
117     }
118 
119     /* Year */
120     if (len >= 7) {
121 	tm.tm_year = atoi(date+6);
122 
123 	/* tm_year up 1900 ... */
124 	if (tm.tm_year > 1900)
125 	    tm.tm_year -= 1900;
126     }
127 
128 #if DEBUG
129     printf("Mktime: %d %d %d %s\n", (int)mktime(&tm), (int)t, len,
130 	   asctime(&tm));
131 #endif
132     return(mktime(&tm));
133 }
134 
135 /*
136  * Possible date formats include any combination of:
137  *	3-charmonth			(January, Jan, Jan)
138  *	3-charweekday			(Friday, Monday, mon.)
139  *	numeric month or day		(1, 2, 04)
140  *
141  * Any character may separate them, or they may not be separated.  Any line,
142  * following a line that is matched, that starts with "whitespace", is shown
143  * along with the matched line.
144  */
145 int
146 isnow(endp, monthp, dayp, varp)
147 	char *endp;
148 	int	*monthp;
149 	int	*dayp;
150 	int	*varp;
151 {
152 	int day, flags, month, v1, v2;
153 
154 	/*
155 	 * CONVENTION
156 	 *
157 	 * Month:     1-12
158 	 * Monthname: Jan .. Dec
159 	 * Day:       1-31
160 	 * Weekday:   Mon-Sun
161 	 *
162 	 */
163 
164 	flags = 0;
165 
166 	/* read first field */
167 	/* didn't recognize anything, skip it */
168 	if (!(v1 = getfield(endp, &endp, &flags)))
169 		return (0);
170 
171 	/* Easter or Easter depending days */
172 	if (flags & F_EASTER)
173 	    day = v1 - 1; /* days since January 1 [0-365] */
174 
175 	 /*
176 	  * 1. {Weekday,Day} XYZ ...
177 	  *
178 	  *    where Day is > 12
179 	  */
180 	else if (flags & F_ISDAY || v1 > 12) {
181 
182 		/* found a day; day: 1-31 or weekday: 1-7 */
183 		day = v1;
184 
185 		/* {Day,Weekday} {Month,Monthname} ... */
186 		/* if no recognizable month, assume just a day alone
187 		 * in other words, find month or use current month */
188 		if (!(month = getfield(endp, &endp, &flags)))
189 			month = tp->tm_mon + 1;
190 	}
191 
192 	/* 2. {Monthname} XYZ ... */
193 	else if (flags & F_ISMONTH) {
194 		month = v1;
195 
196 		/* Monthname {day,weekday} */
197 		/* if no recognizable day, assume the first day in month */
198 		if (!(day = getfield(endp, &endp, &flags)))
199 			day = 1;
200 	}
201 
202 	/* Hm ... */
203 	else {
204 		v2 = getfield(endp, &endp, &flags);
205 
206 		/*
207 		 * {Day} {Monthname} ...
208 		 * where Day <= 12
209 		 */
210 		if (flags & F_ISMONTH) {
211 			day = v1;
212 			month = v2;
213 			*varp = 0;
214 		}
215 
216 		/* {Month} {Weekday,Day} ...  */
217 		else {
218 			/* F_ISDAY set, v2 > 12, or no way to tell */
219 			month = v1;
220 			/* if no recognizable day, assume the first */
221 			day = v2 ? v2 : 1;
222 			*varp = 0;
223 		}
224 	}
225 
226 	/* convert Weekday into *next*  Day,
227 	 * e.g.: 'Sunday' -> 22
228 	 *       'SunayLast' -> ??
229 	 */
230 	if (flags & F_ISDAY) {
231 #if DEBUG
232 	    fprintf(stderr, "\nday: %d %s month %d\n", day, endp, month);
233 #endif
234 
235 	    *varp = 1;
236 	    /* variable weekday, SundayLast, MondayFirst ... */
237 	    if (day < 0 || day >= 10) {
238 
239 		/* negative offset; last, -4 .. -1 */
240 		if (day < 0) {
241 		    v1 = day/10 - 1;          /* offset -4 ... -1 */
242 	            day = 10 + (day % 10);    /* day 1 ... 7 */
243 
244 		    /* day, eg '22th' */
245 		    v2 = tp->tm_mday + (((day - 1) - tp->tm_wday + 7) % 7);
246 
247 		    /* (month length - day) / 7 + 1 */
248 		    if (((int)((cumdays[month+1] -
249 		               cumdays[month] - v2) / 7) + 1) == -v1)
250 			/* bingo ! */
251 			day = v2;
252 
253 		    /* set to yesterday */
254 		    else
255 			day = tp->tm_mday - 1;
256 		}
257 
258 		/* first, second ... +1 ... +5 */
259 		else {
260 		    v1 = day/10;        /* offset: +1 (first Sunday) ... */
261 		    day = day % 10;
262 
263 		    /* day, eg '22th' */
264 		    v2 = tp->tm_mday + (((day - 1) - tp->tm_wday + 7) % 7);
265 
266 		    /* Hurrah! matched */
267 		    if ( ((v2 - 1 + 7) / 7) == v1 )
268 			day = v2;
269 
270 		    /* set to yesterday */
271 		    else
272 			day = tp->tm_mday - 1;
273 		}
274 	    }
275 
276 	    /* wired */
277 	    else {
278 		day = tp->tm_mday + (((day - 1) - tp->tm_wday + 7) % 7);
279 		*varp = 1;
280 	    }
281 	}
282 
283 #if DEBUG
284 	fprintf(stderr, "day2: day %d yday %d\n", day, tp->tm_yday);
285 #endif
286 	if (!(flags & F_EASTER)) {
287 	    *monthp = month;
288 	    *dayp = day;
289 	    day = cumdays[month] + day;
290 	}
291 	else {
292 	    for (v1 = 0; day > cumdays[v1]; v1++)
293 		;
294 	    *monthp = v1 - 1;
295 	    *dayp = day - cumdays[v1 - 1];
296 	    *varp = 1;
297 	}
298 
299 	/* if today or today + offset days */
300 	if (day >= tp->tm_yday - f_dayBefore &&
301 	    day <= tp->tm_yday + offset + f_dayAfter)
302 		return (1);
303 
304 	/* if number of days left in this year + days to event in next year */
305 	if (yrdays - tp->tm_yday + day <= offset + f_dayAfter ||
306 	    /* a year backward, eg. 6 Jan and 10 days before -> 27. Dec */
307 	    tp->tm_yday + day - f_dayBefore < 0
308 	    )
309 		return (1);
310 	return (0);
311 }
312 
313 
314 int
315 getmonth(s)
316 	register char *s;
317 {
318 	register char **p;
319 
320 	for (p = months; *p; ++p)
321 		if (!strncasecmp(s, *p, 3))
322 			return ((p - months) + 1);
323 	return (0);
324 }
325 
326 
327 int
328 getday(s)
329 	register char *s;
330 {
331 	register char **p;
332 
333 	for (p = days; *p; ++p)
334 		if (!strncasecmp(s, *p, 3))
335 			return ((p - days) + 1);
336 	return (0);
337 }
338 
339 /* return offset for variable weekdays
340  * -1 -> last weekday in month
341  * +1 -> first weekday in month
342  * ... etc ...
343  */
344 int
345 getdayvar(s)
346 	register char *s;
347 {
348 	register int offset;
349 
350 
351 	offset = strlen(s);
352 
353 
354 	/* Sun+1 or Wednesday-2
355 	 *    ^              ^   */
356 
357 	/* printf ("x: %s %s %d\n", s, s + offset - 2, offset); */
358 	switch(*(s + offset - 2)) {
359 	case '-':
360 	    return(-(atoi(s + offset - 1)));
361 	    break;
362 	case '+':
363 	    return(atoi(s + offset - 1));
364 	    break;
365 	}
366 
367 
368 	/*
369 	 * some aliases: last, first, second, third, fourth
370 	 */
371 
372 	/* last */
373 	if      (offset > 4 && !strcasecmp(s + offset - 4, "last"))
374 	    return(-1);
375 	else if (offset > 5 && !strcasecmp(s + offset - 5, "first"))
376 	    return(+1);
377 	else if (offset > 6 && !strcasecmp(s + offset - 6, "second"))
378 	    return(+2);
379 	else if (offset > 5 && !strcasecmp(s + offset - 5, "third"))
380 	    return(+3);
381 	else if (offset > 6 && !strcasecmp(s + offset - 6, "fourth"))
382 	    return(+4);
383 
384 
385 	/* no offset detected */
386 	return(0);
387 }
388