Annotation of src/usr.bin/calendar/day.c, Revision 1.15
1.15 ! millert 1: /* $OpenBSD: day.c,v 1.14 2001/11/19 19:02:13 mpech Exp $ */
1.1 millert 2:
3: /*
4: * Copyright (c) 1989, 1993, 1994
5: * The Regents of the University of California. All rights reserved.
6: *
7: * Redistribution and use in source and binary forms, with or without
8: * modification, are permitted provided that the following conditions
9: * are met:
10: * 1. Redistributions of source code must retain the above copyright
11: * notice, this list of conditions and the following disclaimer.
12: * 2. Redistributions in binary form must reproduce the above copyright
13: * notice, this list of conditions and the following disclaimer in the
14: * documentation and/or other materials provided with the distribution.
1.15 ! millert 15: * 3. Neither the name of the University nor the names of its contributors
1.1 millert 16: * may be used to endorse or promote products derived from this software
17: * without specific prior written permission.
18: *
19: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29: * SUCH DAMAGE.
30: */
31:
32: #ifndef lint
33: static const char copyright[] =
34: "@(#) Copyright (c) 1989, 1993\n\
35: The Regents of the University of California. All rights reserved.\n";
36: #endif /* not lint */
37:
38: #ifndef lint
39: #if 0
40: static const char sccsid[] = "@(#)calendar.c 8.3 (Berkeley) 3/25/94";
41: #else
1.15 ! millert 42: static char rcsid[] = "$OpenBSD: day.c,v 1.14 2001/11/19 19:02:13 mpech Exp $";
1.1 millert 43: #endif
44: #endif /* not lint */
45:
46: #include <sys/types.h>
47: #include <sys/uio.h>
48:
49: #include <ctype.h>
50: #include <err.h>
51: #include <locale.h>
52: #include <stdio.h>
53: #include <stdlib.h>
54: #include <string.h>
55: #include <time.h>
56: #include <tzfile.h>
57:
58: #include "pathnames.h"
59: #include "calendar.h"
60:
1.7 pjanzen 61: #define WEEKLY 1
62: #define MONTHLY 2
63: #define YEARLY 3
64:
1.1 millert 65: struct tm *tp;
1.7 pjanzen 66: int *cumdays, offset;
1.1 millert 67: char dayname[10];
68:
69:
70: /* 1-based month, 0-based days, cumulative */
71: int daytab[][14] = {
72: { 0, -1, 30, 58, 89, 119, 150, 180, 211, 242, 272, 303, 333, 364 },
73: { 0, -1, 30, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 },
74: };
75:
76: static char *days[] = {
77: "sun", "mon", "tue", "wed", "thu", "fri", "sat", NULL,
78: };
79:
80: static char *months[] = {
81: "jan", "feb", "mar", "apr", "may", "jun",
82: "jul", "aug", "sep", "oct", "nov", "dec", NULL,
83: };
84:
85: static struct fixs fndays[8]; /* full national days names */
86: static struct fixs ndays[8]; /* short national days names */
87:
88: static struct fixs fnmonths[13]; /* full national months names */
89: static struct fixs nmonths[13]; /* short national month names */
90:
91:
92: void setnnames(void)
93: {
94: char buf[80];
95: int i, l;
96: struct tm tm;
97:
98: for (i = 0; i < 7; i++) {
99: tm.tm_wday = i;
1.3 millert 100: l = strftime(buf, sizeof(buf), "%a", &tm);
101: for (; l > 0 && isspace((int)buf[l - 1]); l--)
1.1 millert 102: ;
103: buf[l] = '\0';
104: if (ndays[i].name != NULL)
105: free(ndays[i].name);
106: if ((ndays[i].name = strdup(buf)) == NULL)
1.11 pjanzen 107: err(1, NULL);
1.1 millert 108: ndays[i].len = strlen(buf);
109:
1.3 millert 110: l = strftime(buf, sizeof(buf), "%A", &tm);
111: for (; l > 0 && isspace((int)buf[l - 1]); l--)
1.1 millert 112: ;
113: buf[l] = '\0';
114: if (fndays[i].name != NULL)
115: free(fndays[i].name);
116: if ((fndays[i].name = strdup(buf)) == NULL)
1.11 pjanzen 117: err(1, NULL);
1.1 millert 118: fndays[i].len = strlen(buf);
119: }
120:
121: for (i = 0; i < 12; i++) {
122: tm.tm_mon = i;
1.3 millert 123: l = strftime(buf, sizeof(buf), "%b", &tm);
124: for (; l > 0 && isspace((int)buf[l - 1]); l--)
1.1 millert 125: ;
126: buf[l] = '\0';
127: if (nmonths[i].name != NULL)
128: free(nmonths[i].name);
129: if ((nmonths[i].name = strdup(buf)) == NULL)
1.11 pjanzen 130: err(1, NULL);
1.1 millert 131: nmonths[i].len = strlen(buf);
132:
1.3 millert 133: l = strftime(buf, sizeof(buf), "%B", &tm);
134: for (; l > 0 && isspace((int)buf[l - 1]); l--)
1.1 millert 135: ;
136: buf[l] = '\0';
137: if (fnmonths[i].name != NULL)
138: free(fnmonths[i].name);
139: if ((fnmonths[i].name = strdup(buf)) == NULL)
1.11 pjanzen 140: err(1, NULL);
1.1 millert 141: fnmonths[i].len = strlen(buf);
142: }
1.7 pjanzen 143: /* Hardwired special events */
144: spev[0].name = strdup(EASTER);
145: spev[0].nlen = EASTERNAMELEN;
146: spev[0].getev = easter;
147: spev[1].name = strdup(PASKHA);
148: spev[1].nlen = PASKHALEN;
149: spev[1].getev = paskha;
150: for (i = 0; i < NUMEV; i++) {
151: if (spev[i].name == NULL)
1.11 pjanzen 152: err(1, NULL);
1.7 pjanzen 153: spev[i].uname = NULL;
154: }
1.1 millert 155: }
156:
157: void
158: settime(now)
1.7 pjanzen 159: time_t *now;
1.1 millert 160: {
1.7 pjanzen 161: tp = localtime(now);
162: tp->tm_sec = 0;
163: tp->tm_min = 0;
164: /* Avoid getting caught by a timezone shift; set time to noon */
165: tp->tm_isdst = 0;
166: tp->tm_hour = 12;
167: *now = mktime(tp);
168: if (isleap(tp->tm_year + TM_YEAR_BASE))
1.1 millert 169: cumdays = daytab[1];
1.7 pjanzen 170: else
1.1 millert 171: cumdays = daytab[0];
172: /* Friday displays Monday's events */
173: offset = tp->tm_wday == 5 ? 3 : 1;
1.7 pjanzen 174: if (f_dayAfter)
175: offset = 0; /* Except not when range is set explicitly */
1.1 millert 176: header[5].iov_base = dayname;
177:
178: (void) setlocale(LC_TIME, "C");
179: header[5].iov_len = strftime(dayname, sizeof(dayname), "%A", tp);
180: (void) setlocale(LC_TIME, "");
181:
182: setnnames();
183: }
184:
1.2 millert 185: /* convert [Year][Month]Day into unix time (since 1970)
186: * Year: two or four digits, Month: two digits, Day: two digits
1.1 millert 187: */
188: time_t Mktime (date)
189: char *date;
190: {
191: time_t t;
192: int len;
193: struct tm tm;
194:
195: (void)time(&t);
196: tp = localtime(&t);
197:
198: len = strlen(date);
1.2 millert 199: if (len < 2)
200: return((time_t)-1);
1.1 millert 201: tm.tm_sec = 0;
202: tm.tm_min = 0;
1.5 pjanzen 203: /* Avoid getting caught by a timezone shift; set time to noon */
204: tm.tm_isdst = 0;
205: tm.tm_hour = 12;
1.1 millert 206: tm.tm_wday = 0;
207: tm.tm_mday = tp->tm_mday;
208: tm.tm_mon = tp->tm_mon;
209: tm.tm_year = tp->tm_year;
210:
1.2 millert 211: /* Day */
212: tm.tm_mday = atoi(date + len - 2);
1.1 millert 213:
1.2 millert 214: /* Month */
1.1 millert 215: if (len >= 4) {
1.2 millert 216: *(date + len - 2) = '\0';
217: tm.tm_mon = atoi(date + len - 4) - 1;
1.1 millert 218: }
219:
220: /* Year */
1.5 pjanzen 221: if (len >= 6) {
1.7 pjanzen 222: *(date + len - 4) = '\0';
223: tm.tm_year = atoi(date);
1.1 millert 224:
1.4 deraadt 225: /* tm_year up TM_YEAR_BASE ... */
1.5 pjanzen 226: if (tm.tm_year < 69) /* Y2K */
1.4 deraadt 227: tm.tm_year += 2000 - TM_YEAR_BASE;
228: else if (tm.tm_year < 100)
229: tm.tm_year += 1900 - TM_YEAR_BASE;
230: else if (tm.tm_year > TM_YEAR_BASE)
231: tm.tm_year -= TM_YEAR_BASE;
1.1 millert 232: }
233:
234: #if DEBUG
235: printf("Mktime: %d %d %d %s\n", (int)mktime(&tm), (int)t, len,
236: asctime(&tm));
237: #endif
238: return(mktime(&tm));
239: }
240:
241: /*
242: * Possible date formats include any combination of:
243: * 3-charmonth (January, Jan, Jan)
244: * 3-charweekday (Friday, Monday, mon.)
245: * numeric month or day (1, 2, 04)
246: *
1.10 pjanzen 247: * Any character except \t or '*' may separate them, or they may not be
248: * separated. Any line following a line that is matched, that starts
249: * with \t, is shown along with the matched line.
1.1 millert 250: */
1.6 pjanzen 251: struct match *
1.12 mickey 252: isnow(endp, bodun)
1.1 millert 253: char *endp;
1.12 mickey 254: int bodun;
1.1 millert 255: {
1.7 pjanzen 256: int day = 0, flags = 0, month = 0, v1, v2, i;
257: int monthp, dayp, varp = 0;
258: struct match *matches = NULL, *tmp, *tmp2;
259: int interval = YEARLY; /* how frequently the event repeats. */
260: int vwd = 0; /* Variable weekday */
261: time_t tdiff, ttmp;
262: struct tm tmtmp;
1.1 millert 263:
264: /*
265: * CONVENTION
266: *
267: * Month: 1-12
268: * Monthname: Jan .. Dec
269: * Day: 1-31
270: * Weekday: Mon-Sun
271: *
272: */
273:
274: /* read first field */
275: /* didn't recognize anything, skip it */
276: if (!(v1 = getfield(endp, &endp, &flags)))
1.6 pjanzen 277: return (NULL);
1.1 millert 278:
1.12 mickey 279: /* adjust bodun rate */
280: if (bodun && !bodun_always)
281: bodun = !(arc4random() % 3);
282:
1.1 millert 283: /* Easter or Easter depending days */
1.7 pjanzen 284: if (flags & F_SPECIAL)
285: vwd = v1;
1.1 millert 286:
287: /*
288: * 1. {Weekday,Day} XYZ ...
289: *
290: * where Day is > 12
291: */
292: else if (flags & F_ISDAY || v1 > 12) {
293:
1.7 pjanzen 294: /* found a day; day: 13-31 or weekday: 1-7 */
1.1 millert 295: day = v1;
296:
297: /* {Day,Weekday} {Month,Monthname} ... */
1.7 pjanzen 298: /* if no recognizable month, assume just a day alone -- this is
299: * very unlikely and can only happen after the first 12 days.
300: * --find month or use current month */
301: if (!(month = getfield(endp, &endp, &flags))) {
1.1 millert 302: month = tp->tm_mon + 1;
1.7 pjanzen 303: /* F_ISDAY is set only if a weekday was spelled out */
304: /* F_ISDAY must be set if 0 < day < 8 */
305: if ((day <= 7) && (day >= 1))
306: interval = WEEKLY;
307: else
308: interval = MONTHLY;
309: } else if ((day <= 7) && (day >= 1))
310: day += 10;
311: /* it's a weekday; make it the first one of the month */
312: if (month == -1) {
313: month = tp->tm_mon + 1;
314: interval = MONTHLY;
315: }
316: if ((month > 12) || (month < 1))
317: return (NULL);
1.1 millert 318: }
319:
320: /* 2. {Monthname} XYZ ... */
321: else if (flags & F_ISMONTH) {
322: month = v1;
1.7 pjanzen 323: if (month == -1) {
324: month = tp->tm_mon + 1;
325: interval = MONTHLY;
326: }
1.1 millert 327: /* Monthname {day,weekday} */
328: /* if no recognizable day, assume the first day in month */
329: if (!(day = getfield(endp, &endp, &flags)))
330: day = 1;
1.7 pjanzen 331: /* If a weekday was spelled out without an ordering,
332: * assume the first of that day in the month */
333: if ((flags & F_ISDAY) && (day >= 1) && (day <=7))
334: day += 10;
1.1 millert 335: }
336:
337: /* Hm ... */
338: else {
339: v2 = getfield(endp, &endp, &flags);
340:
341: /*
342: * {Day} {Monthname} ...
343: * where Day <= 12
344: */
345: if (flags & F_ISMONTH) {
346: day = v1;
347: month = v2;
1.7 pjanzen 348: if (month == -1) {
349: month = tp->tm_mon + 1;
350: interval = MONTHLY;
351: }
1.1 millert 352: }
353:
354: /* {Month} {Weekday,Day} ... */
355: else {
356: /* F_ISDAY set, v2 > 12, or no way to tell */
357: month = v1;
358: /* if no recognizable day, assume the first */
359: day = v2 ? v2 : 1;
1.7 pjanzen 360: if ((flags & F_ISDAY) && (day >= 1) && (day <= 7))
361: day += 10;
1.1 millert 362: }
363: }
364:
365: /* convert Weekday into *next* Day,
366: * e.g.: 'Sunday' -> 22
1.5 pjanzen 367: * 'SundayLast' -> ??
1.1 millert 368: */
369: if (flags & F_ISDAY) {
370: #if DEBUG
1.7 pjanzen 371: fprintf(stderr, "\nday: %d %s month %d\n", day, endp, month);
1.1 millert 372: #endif
373:
1.7 pjanzen 374: varp = 1;
375: /* variable weekday, SundayLast, MondayFirst ... */
376: if (day < 0 || day >= 10)
377: vwd = day;
378: else {
379: day = tp->tm_mday + (((day - 1) - tp->tm_wday + 7) % 7);
380: interval = WEEKLY;
381: }
382: } else
383: /* Check for silliness. Note we still catch Feb 29 */
384: if (!(flags & F_SPECIAL) &&
385: (day > (cumdays[month + 1] - cumdays[month]) || day < 1)) {
386: if (!((month == 2 && day == 29) ||
387: (interval == MONTHLY && day <= 31)))
388: return (NULL);
1.1 millert 389: }
390:
1.7 pjanzen 391: if (!(flags & F_SPECIAL)) {
392: monthp = month;
393: dayp = day;
394: day = cumdays[month] + day;
1.5 pjanzen 395: #if DEBUG
1.7 pjanzen 396: fprintf(stderr, "day2: day %d(%d) yday %d\n", dayp, day, tp->tm_yday);
1.5 pjanzen 397: #endif
1.7 pjanzen 398: /* Speed up processing for the most common situation: yearly events
399: * when the interval being checked is less than a month or so (this
400: * could be less than a year, but then we have to start worrying about
401: * leap years). Only one event can match, and it's easy to find.
402: * Note we can't check special events, because they can wander widely.
403: */
404: if (((v1 = offset + f_dayAfter) < 50) && (interval == YEARLY)) {
405: memcpy(&tmtmp, tp, sizeof(struct tm));
406: tmtmp.tm_mday = dayp;
407: tmtmp.tm_mon = monthp - 1;
1.8 pjanzen 408: if (vwd) {
409: /* We want the event next year if it's late now
410: * this year. The 50-day limit means we don't have to
411: * worry if next year is or isn't a leap year.
412: */
413: if (tp->tm_yday > 300 && tmtmp.tm_mon <= 1)
414: variable_weekday(&vwd, tmtmp.tm_mon + 1,
415: tmtmp.tm_year + TM_YEAR_BASE + 1);
416: else
417: variable_weekday(&vwd, tmtmp.tm_mon + 1,
418: tmtmp.tm_year + TM_YEAR_BASE);
419: day = cumdays[tmtmp.tm_mon + 1] + vwd;
420: tmtmp.tm_mday = vwd;
421: }
1.7 pjanzen 422: v2 = day - tp->tm_yday;
423: if ((v2 > v1) || (v2 < 0)) {
424: if ((v2 += isleap(tp->tm_year + TM_YEAR_BASE) ? 366 : 365)
425: <= v1)
426: tmtmp.tm_year++;
1.12 mickey 427: else if(!bodun || (day - tp->tm_yday) != -1)
1.7 pjanzen 428: return(NULL);
429: }
430: if ((tmp = malloc(sizeof(struct match))) == NULL)
1.11 pjanzen 431: err(1, NULL);
1.13 mickey 432:
433: if (bodun && (day - tp->tm_yday) == -1) {
434: tmp->when = f_time - 1 * SECSPERDAY;
435: tmtmp.tm_mday++;
436: tmp->bodun = 1;
437: } else {
438: tmp->when = f_time + v2 * SECSPERDAY;
439: tmp->bodun = 0;
440: }
441:
1.7 pjanzen 442: (void)mktime(&tmtmp);
443: if (strftime(tmp->print_date,
444: sizeof(tmp->print_date),
445: /* "%a %b %d", &tm); Skip weekdays */
446: "%b %d", &tmtmp) == 0)
447: tmp->print_date[sizeof(tmp->print_date) - 1] = '\0';
1.12 mickey 448:
1.7 pjanzen 449: tmp->var = varp;
450: tmp->next = NULL;
451: return(tmp);
452: }
1.1 millert 453: }
454: else {
1.7 pjanzen 455: varp = 1;
456: /* Set up v1 to the event number and ... */
457: v1 = vwd % (NUMEV + 1) - 1;
458: vwd /= (NUMEV + 1);
459: if (v1 < 0) {
460: v1 += NUMEV + 1;
461: vwd--;
462: }
463: dayp = monthp = 1; /* Why not */
1.1 millert 464: }
465:
1.7 pjanzen 466: /* Compare to past and coming instances of the event. The i == 0 part
467: * of the loop corresponds to this specific instance. Note that we
468: * can leave things sort of higgledy-piggledy since a mktime() happens
469: * on this before anything gets printed. Also note that even though
470: * we've effectively gotten rid of f_dayBefore, we still have to check
471: * the one prior event for situations like "the 31st of every month"
472: * and "yearly" events which could happen twice in one year but not in
473: * the next */
474: tmp2 = matches;
475: for (i = -1; i < 2; i++) {
476: memcpy(&tmtmp, tp, sizeof(struct tm));
477: tmtmp.tm_mday = dayp;
478: tmtmp.tm_mon = month = monthp - 1;
479: do {
480: v2 = 0;
481: switch (interval) {
482: case WEEKLY:
483: tmtmp.tm_mday += 7 * i;
484: break;
485: case MONTHLY:
486: month += i;
487: tmtmp.tm_mon = month;
488: switch(tmtmp.tm_mon) {
489: case -1:
490: tmtmp.tm_mon = month = 11;
491: tmtmp.tm_year--;
492: break;
493: case 12:
494: tmtmp.tm_mon = month = 0;
495: tmtmp.tm_year++;
496: break;
497: }
498: if (vwd) {
499: v1 = vwd;
500: variable_weekday(&v1, tmtmp.tm_mon + 1,
501: tmtmp.tm_year + TM_YEAR_BASE);
502: tmtmp.tm_mday = v1;
503: } else
504: tmtmp.tm_mday = dayp;
505: break;
506: case YEARLY:
507: default:
508: tmtmp.tm_year += i;
509: if (flags & F_SPECIAL) {
510: tmtmp.tm_mon = 0; /* Gee, mktime() is nice */
511: tmtmp.tm_mday = spev[v1].getev(tmtmp.tm_year +
1.9 pjanzen 512: TM_YEAR_BASE) + vwd;
1.7 pjanzen 513: } else if (vwd) {
514: v1 = vwd;
515: variable_weekday(&v1, tmtmp.tm_mon + 1,
516: tmtmp.tm_year + TM_YEAR_BASE);
517: tmtmp.tm_mday = v1;
518: } else {
519: /* Need the following to keep Feb 29 from
520: * becoming Mar 1 */
521: tmtmp.tm_mday = dayp;
522: tmtmp.tm_mon = monthp - 1;
523: }
524: break;
525: }
526: /* How many days apart are we */
527: if ((ttmp = mktime(&tmtmp)) == -1)
528: warnx("time out of range: %s", endp);
529: else {
530: tdiff = difftime(ttmp, f_time)/ SECSPERDAY;
1.12 mickey 531: if (tdiff <= offset + f_dayAfter ||
532: (bodun && tdiff == -1)) {
533: if (tdiff >= 0 ||
534: (bodun && tdiff == -1)) {
1.7 pjanzen 535: if ((tmp = malloc(sizeof(struct match))) == NULL)
1.11 pjanzen 536: err(1, NULL);
1.7 pjanzen 537: tmp->when = ttmp;
538: if (strftime(tmp->print_date,
539: sizeof(tmp->print_date),
540: /* "%a %b %d", &tm); Skip weekdays */
541: "%b %d", &tmtmp) == 0)
542: tmp->print_date[sizeof(tmp->print_date) - 1] = '\0';
1.13 mickey 543: tmp->bodun = bodun && tdiff == -1;
1.7 pjanzen 544: tmp->var = varp;
545: tmp->next = NULL;
546: if (tmp2)
547: tmp2->next = tmp;
548: else
549: matches = tmp;
550: tmp2 = tmp;
551: v2 = (i == 1) ? 1 : 0;
552: }
553: } else
554: i = 2; /* No point checking in the future */
555: }
556: } while (v2 != 0);
1.6 pjanzen 557: }
1.7 pjanzen 558: return (matches);
1.1 millert 559: }
560:
561:
562: int
563: getmonth(s)
1.14 mpech 564: char *s;
1.1 millert 565: {
1.14 mpech 566: char **p;
1.1 millert 567: struct fixs *n;
568:
569: for (n = fnmonths; n->name; ++n)
570: if (!strncasecmp(s, n->name, n->len))
571: return ((n - fnmonths) + 1);
572: for (n = nmonths; n->name; ++n)
573: if (!strncasecmp(s, n->name, n->len))
574: return ((n - nmonths) + 1);
575: for (p = months; *p; ++p)
576: if (!strncasecmp(s, *p, 3))
577: return ((p - months) + 1);
578: return (0);
579: }
580:
581:
582: int
583: getday(s)
1.14 mpech 584: char *s;
1.1 millert 585: {
1.14 mpech 586: char **p;
1.1 millert 587: struct fixs *n;
588:
589: for (n = fndays; n->name; ++n)
590: if (!strncasecmp(s, n->name, n->len))
591: return ((n - fndays) + 1);
592: for (n = ndays; n->name; ++n)
593: if (!strncasecmp(s, n->name, n->len))
594: return ((n - ndays) + 1);
595: for (p = days; *p; ++p)
596: if (!strncasecmp(s, *p, 3))
597: return ((p - days) + 1);
598: return (0);
599: }
600:
601: /* return offset for variable weekdays
602: * -1 -> last weekday in month
603: * +1 -> first weekday in month
604: * ... etc ...
605: */
606: int
607: getdayvar(s)
1.14 mpech 608: char *s;
1.1 millert 609: {
1.14 mpech 610: int offset;
1.1 millert 611:
612:
613: offset = strlen(s);
614:
615: /* Sun+1 or Wednesday-2
616: * ^ ^ */
617:
618: /* printf ("x: %s %s %d\n", s, s + offset - 2, offset); */
619: switch(*(s + offset - 2)) {
620: case '-':
621: case '+':
1.7 pjanzen 622: return(atoi(s + offset - 2));
1.1 millert 623: break;
624: }
625:
626: /*
627: * some aliases: last, first, second, third, fourth
628: */
629:
630: /* last */
631: if (offset > 4 && !strcasecmp(s + offset - 4, "last"))
632: return(-1);
633: else if (offset > 5 && !strcasecmp(s + offset - 5, "first"))
634: return(+1);
635: else if (offset > 6 && !strcasecmp(s + offset - 6, "second"))
636: return(+2);
637: else if (offset > 5 && !strcasecmp(s + offset - 5, "third"))
638: return(+3);
639: else if (offset > 6 && !strcasecmp(s + offset - 6, "fourth"))
640: return(+4);
641:
642: /* no offset detected */
643: return(0);
1.7 pjanzen 644: }
645:
646:
647: int
648: foy(year)
649: int year;
650: {
651: /* 0-6; what weekday Jan 1 is */
652: year--;
653: return ((1 - year/100 + year/400 + (int)(365.25 * year)) % 7);
654: }
655:
656:
657:
658: void
659: variable_weekday(day, month, year)
660: int *day, month, year;
661: {
662: int v1, v2;
663: int *cumdays;
664: int day1;
665:
666: if (isleap(year))
667: cumdays = daytab[1];
668: else
669: cumdays = daytab[0];
670: day1 = foy(year);
671: /* negative offset; last, -4 .. -1 */
672: if (*day < 0) {
673: v1 = *day/10 - 1; /* offset -4 ... -1 */
674: *day = 10 + (*day % 10); /* day 1 ... 7 */
675:
676: /* which weekday the end of the month is (1-7) */
677: v2 = (cumdays[month + 1] + day1) % 7 + 1;
678:
679: /* and subtract enough days */
680: *day = cumdays[month + 1] - cumdays[month] +
681: (v1 + 1) * 7 - (v2 - *day + 7) % 7;
682: #if DEBUG
683: fprintf(stderr, "\nMonth %d ends on weekday %d\n", month, v2);
684: #endif
685: }
686:
687: /* first, second ... +1 ... +5 */
688: else {
689: v1 = *day/10; /* offset */
690: *day = *day % 10;
691:
692: /* which weekday the first of the month is (1-7) */
693: v2 = (cumdays[month] + 1 + day1) % 7 + 1;
694:
695: /* and add enough days */
696: *day = 1 + (v1 - 1) * 7 + (*day - v2 + 7) % 7;
697: #if DEBUG
698: fprintf(stderr, "\nMonth %d starts on weekday %d\n", month, v2);
699: #endif
700: }
1.1 millert 701: }
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