1 /*-
2 * Copyright (c) 1997 Brian Somers <brian@Awfulhak.org>
3 * 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 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27 #include <sys/cdefs.h>
28 #include <err.h>
29 #include <time.h>
30 #include <stdint.h>
31 #include <string.h>
32 #include <stdlib.h>
33 #include "vary.h"
34
35 struct trans {
36 int64_t val;
37 const char *str;
38 };
39
40 static struct trans trans_mon[] = {
41 { 1, "january" }, { 2, "february" }, { 3, "march" }, { 4, "april" },
42 { 5, "may"}, { 6, "june" }, { 7, "july" }, { 8, "august" },
43 { 9, "september" }, { 10, "october" }, { 11, "november" }, { 12, "december" },
44 { -1, NULL }
45 };
46
47 static struct trans trans_wday[] = {
48 { 0, "sunday" }, { 1, "monday" }, { 2, "tuesday" }, { 3, "wednesday" },
49 { 4, "thursday" }, { 5, "friday" }, { 6, "saturday" },
50 { -1, NULL }
51 };
52
53 static char digits[] = "0123456789";
54 static int adjhour(struct tm *, char, int64_t, int);
55
56 static int
domktime(struct tm * t,char type)57 domktime(struct tm *t, char type)
58 {
59 time_t ret;
60
61 while ((ret = mktime(t)) == -1 && t->tm_year > 68 && t->tm_year < 138)
62 /* While mktime() fails, adjust by an hour */
63 adjhour(t, type == '-' ? type : '+', 1, 0);
64
65 return ret;
66 }
67
68 static int
trans(const struct trans t[],const char * arg)69 trans(const struct trans t[], const char *arg)
70 {
71 int f;
72
73 for (f = 0; t[f].val != -1; f++)
74 if (!strncasecmp(t[f].str, arg, 3) ||
75 !strncasecmp(t[f].str, arg, strlen(t[f].str)))
76 return t[f].val;
77
78 return -1;
79 }
80
81 struct vary *
vary_append(struct vary * v,char * arg)82 vary_append(struct vary *v, char *arg)
83 {
84 struct vary *result, **nextp;
85
86 if (v) {
87 result = v;
88 while (v->next)
89 v = v->next;
90 nextp = &v->next;
91 } else
92 nextp = &result;
93
94 if ((*nextp = (struct vary *)malloc(sizeof(struct vary))) == NULL)
95 err(1, "malloc");
96 (*nextp)->arg = arg;
97 (*nextp)->next = NULL;
98 return result;
99 }
100
101 static int mdays[12] = { 31, 0, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
102
103 static int
daysinmonth(const struct tm * t)104 daysinmonth(const struct tm *t)
105 {
106 int year;
107
108 year = t->tm_year + 1900;
109
110 if (t->tm_mon == 1)
111 if (!(year % 400))
112 return 29;
113 else if (!(year % 100))
114 return 28;
115 else if (!(year % 4))
116 return 29;
117 else
118 return 28;
119 else if (t->tm_mon >= 0 && t->tm_mon < 12)
120 return mdays[t->tm_mon];
121
122 return 0;
123 }
124
125
126 static int
adjyear(struct tm * t,char type,int64_t val,int mk)127 adjyear(struct tm *t, char type, int64_t val, int mk)
128 {
129 switch (type) {
130 case '+':
131 t->tm_year += val;
132 break;
133 case '-':
134 t->tm_year -= val;
135 break;
136 default:
137 t->tm_year = val;
138 if (t->tm_year < 69)
139 t->tm_year += 100; /* as per date.c */
140 else if (t->tm_year > 1900)
141 t->tm_year -= 1900; /* struct tm holds years since 1900 */
142 break;
143 }
144 return !mk || domktime(t, type) != -1;
145 }
146
147 static int
adjmon(struct tm * t,char type,int64_t val,int istext,int mk)148 adjmon(struct tm *t, char type, int64_t val, int istext, int mk)
149 {
150 int lmdays;
151
152 if (val < 0)
153 return 0;
154
155 switch (type) {
156 case '+':
157 if (istext) {
158 if (val <= t->tm_mon)
159 val += 11 - t->tm_mon; /* early next year */
160 else
161 val -= t->tm_mon + 1; /* later this year */
162 }
163 if (val) {
164 if (!adjyear(t, '+', (t->tm_mon + val) / 12, 0))
165 return 0;
166 val %= 12;
167 t->tm_mon += val;
168 if (t->tm_mon > 11)
169 t->tm_mon -= 12;
170 }
171 break;
172
173 case '-':
174 if (istext) {
175 if (val-1 > t->tm_mon)
176 val = 13 - val + t->tm_mon; /* later last year */
177 else
178 val = t->tm_mon - val + 1; /* early this year */
179 }
180 if (val) {
181 if (!adjyear(t, '-', val / 12, 0))
182 return 0;
183 val %= 12;
184 if (val > t->tm_mon) {
185 if (!adjyear(t, '-', 1, 0))
186 return 0;
187 val -= 12;
188 }
189 t->tm_mon -= val;
190 }
191 break;
192
193 default:
194 if (val > 12 || val < 1)
195 return 0;
196 t->tm_mon = --val;
197 }
198
199 /* e.g., -v-1m on March, 31 is the last day of February in common sense */
200 lmdays = daysinmonth(t);
201 if (t->tm_mday > lmdays)
202 t->tm_mday = lmdays;
203
204 return !mk || domktime(t, type) != -1;
205 }
206
207 static int
adjday(struct tm * t,char type,int64_t val,int mk)208 adjday(struct tm *t, char type, int64_t val, int mk)
209 {
210 int lmdays;
211
212 switch (type) {
213 case '+':
214 while (val) {
215 lmdays = daysinmonth(t);
216 if (val > lmdays - t->tm_mday) {
217 val -= lmdays - t->tm_mday + 1;
218 t->tm_mday = 1;
219 if (!adjmon(t, '+', 1, 0, 0))
220 return 0;
221 } else {
222 t->tm_mday += val;
223 val = 0;
224 }
225 }
226 break;
227 case '-':
228 while (val)
229 if (val >= t->tm_mday) {
230 val -= t->tm_mday;
231 t->tm_mday = 1;
232 if (!adjmon(t, '-', 1, 0, 0))
233 return 0;
234 t->tm_mday = daysinmonth(t);
235 } else {
236 t->tm_mday -= val;
237 val = 0;
238 }
239 break;
240 default:
241 if (val > 0 && val <= daysinmonth(t))
242 t->tm_mday = val;
243 else
244 return 0;
245 break;
246 }
247
248 return !mk || domktime(t, type) != -1;
249 }
250
251 static int
adjwday(struct tm * t,char type,int64_t val,int istext,int mk)252 adjwday(struct tm *t, char type, int64_t val, int istext, int mk)
253 {
254 if (val < 0)
255 return 0;
256
257 switch (type) {
258 case '+':
259 if (istext)
260 if (val < t->tm_wday)
261 val = 7 - t->tm_wday + val; /* early next week */
262 else
263 val -= t->tm_wday; /* later this week */
264 else
265 val *= 7; /* "-v+5w" == "5 weeks in the future" */
266 return !val || adjday(t, '+', val, mk);
267 case '-':
268 if (istext) {
269 if (val > t->tm_wday)
270 val = 7 - val + t->tm_wday; /* later last week */
271 else
272 val = t->tm_wday - val; /* early this week */
273 } else
274 val *= 7; /* "-v-5w" == "5 weeks ago" */
275 return !val || adjday(t, '-', val, mk);
276 default:
277 if (val < t->tm_wday)
278 return adjday(t, '-', t->tm_wday - val, mk);
279 else if (val > 6)
280 return 0;
281 else if (val > t->tm_wday)
282 return adjday(t, '+', val - t->tm_wday, mk);
283 }
284 return 1;
285 }
286
287 static int
adjhour(struct tm * t,char type,int64_t val,int mk)288 adjhour(struct tm *t, char type, int64_t val, int mk)
289 {
290 if (val < 0)
291 return 0;
292
293 switch (type) {
294 case '+':
295 if (val) {
296 int days;
297
298 days = (t->tm_hour + val) / 24;
299 val %= 24;
300 t->tm_hour += val;
301 t->tm_hour %= 24;
302 if (!adjday(t, '+', days, 0))
303 return 0;
304 }
305 break;
306
307 case '-':
308 if (val) {
309 int days;
310
311 days = val / 24;
312 val %= 24;
313 if (val > t->tm_hour) {
314 days++;
315 val -= 24;
316 }
317 t->tm_hour -= val;
318 if (!adjday(t, '-', days, 0))
319 return 0;
320 }
321 break;
322
323 default:
324 if (val > 23)
325 return 0;
326 t->tm_hour = val;
327 }
328
329 return !mk || domktime(t, type) != -1;
330 }
331
332 static int
adjmin(struct tm * t,char type,int64_t val,int mk)333 adjmin(struct tm *t, char type, int64_t val, int mk)
334 {
335 if (val < 0)
336 return 0;
337
338 switch (type) {
339 case '+':
340 if (val) {
341 if (!adjhour(t, '+', (t->tm_min + val) / 60, 0))
342 return 0;
343 val %= 60;
344 t->tm_min += val;
345 if (t->tm_min > 59)
346 t->tm_min -= 60;
347 }
348 break;
349
350 case '-':
351 if (val) {
352 if (!adjhour(t, '-', val / 60, 0))
353 return 0;
354 val %= 60;
355 if (val > t->tm_min) {
356 if (!adjhour(t, '-', 1, 0))
357 return 0;
358 val -= 60;
359 }
360 t->tm_min -= val;
361 }
362 break;
363
364 default:
365 if (val > 59)
366 return 0;
367 t->tm_min = val;
368 }
369
370 return !mk || domktime(t, type) != -1;
371 }
372
373 static int
adjsec(struct tm * t,char type,int64_t val,int mk)374 adjsec(struct tm *t, char type, int64_t val, int mk)
375 {
376 if (val < 0)
377 return 0;
378
379 switch (type) {
380 case '+':
381 if (val) {
382 if (!adjmin(t, '+', (t->tm_sec + val) / 60, 0))
383 return 0;
384 val %= 60;
385 t->tm_sec += val;
386 if (t->tm_sec > 59)
387 t->tm_sec -= 60;
388 }
389 break;
390
391 case '-':
392 if (val) {
393 if (!adjmin(t, '-', val / 60, 0))
394 return 0;
395 val %= 60;
396 if (val > t->tm_sec) {
397 if (!adjmin(t, '-', 1, 0))
398 return 0;
399 val -= 60;
400 }
401 t->tm_sec -= val;
402 }
403 break;
404
405 default:
406 if (val > 59)
407 return 0;
408 t->tm_sec = val;
409 }
410
411 return !mk || domktime(t, type) != -1;
412 }
413
414 const struct vary *
vary_apply(const struct vary * v,struct tm * t)415 vary_apply(const struct vary *v, struct tm *t)
416 {
417 char type;
418 char which;
419 char *arg;
420 size_t len;
421 int64_t val;
422
423 for (; v; v = v->next) {
424 type = *v->arg;
425 arg = v->arg;
426 if (type == '+' || type == '-')
427 arg++;
428 else
429 type = '\0';
430 len = strlen(arg);
431 if (len < 2)
432 return v;
433
434 if (type == '\0')
435 t->tm_isdst = -1;
436
437 if (strspn(arg, digits) != len-1) {
438 val = trans(trans_wday, arg);
439 if (val != -1) {
440 if (!adjwday(t, type, val, 1, 1))
441 return v;
442 } else {
443 val = trans(trans_mon, arg);
444 if (val != -1) {
445 if (!adjmon(t, type, val, 1, 1))
446 return v;
447 } else
448 return v;
449 }
450 } else {
451 val = atoi(arg);
452 which = arg[len-1];
453
454 switch (which) {
455 case 'S':
456 if (!adjsec(t, type, val, 1))
457 return v;
458 break;
459 case 'M':
460 if (!adjmin(t, type, val, 1))
461 return v;
462 break;
463 case 'H':
464 if (!adjhour(t, type, val, 1))
465 return v;
466 break;
467 case 'd':
468 t->tm_isdst = -1;
469 if (!adjday(t, type, val, 1))
470 return v;
471 break;
472 case 'w':
473 t->tm_isdst = -1;
474 if (!adjwday(t, type, val, 0, 1))
475 return v;
476 break;
477 case 'm':
478 t->tm_isdst = -1;
479 if (!adjmon(t, type, val, 0, 1))
480 return v;
481 break;
482 case 'y':
483 t->tm_isdst = -1;
484 if (!adjyear(t, type, val, 1))
485 return v;
486 break;
487 default:
488 return v;
489 }
490 }
491 }
492 return 0;
493 }
494
495 void
vary_destroy(struct vary * v)496 vary_destroy(struct vary *v)
497 {
498 struct vary *n;
499
500 while (v) {
501 n = v->next;
502 free(v);
503 v = n;
504 }
505 }
506