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 * Lifted from FreeBSD: src/bin/date/vary.c,v 1.15
27 *
28 * $Id: timevary.c,v 1.6 2004/04/20 18:45:48 ejohnst Exp $
29 *
30 */
31
32 #include <time.h>
33 #include <string.h>
34 #include <stdlib.h>
35 #include <errno.h>
36 #include <ctype.h>
37 #include "timevary.h"
38 #include "exif.h"
39
40 struct trans {
41 int val;
42 const char *str;
43 };
44
45 static struct trans trans_mon[] = {
46 { 1, "january" }, { 2, "february" }, { 3, "march" }, { 4, "april" },
47 { 5, "may"}, { 6, "june" }, { 7, "july" }, { 8, "august" },
48 { 9, "september" }, { 10, "october" }, { 11, "november" }, { 12, "december" },
49 { -1, NULL }
50 };
51
52 static struct trans trans_wday[] = {
53 { 0, "sunday" }, { 1, "monday" }, { 2, "tuesday" }, { 3, "wednesday" },
54 { 4, "thursday" }, { 5, "friday" }, { 6, "saturday" },
55 { -1, NULL }
56 };
57
58 static char digits[] = "0123456789";
59 static int adjhour(struct tm *, char, int, int);
60
61 static int
domktime(struct tm * t,char type)62 domktime(struct tm *t, char type)
63 {
64 time_t ret;
65
66 while ((ret = mktime(t)) == -1 && t->tm_year > 68 && t->tm_year < 138)
67 /* While mktime() fails, adjust by an hour */
68 adjhour(t, (char)(type == '-' ? type : '+'), 1, 0);
69
70 return ret;
71 }
72
73 static int
trans(const struct trans t[],const char * arg)74 trans(const struct trans t[], const char *arg)
75 {
76 int f;
77 char tmp[16];
78
79 /* No strncasecmp() in Win32. No month or day over 16 bytes long... */
80
81 for (f = 0; f < sizeof(tmp) && arg[f]; f++)
82 tmp[f] = tolower(arg[f]);
83 tmp[15] = '\0';
84
85 for (f = 0; t[f].val != -1; f++)
86 if (!strncmp(t[f].str, tmp, 3) ||
87 !strncmp(t[f].str, tmp, strlen(t[f].str)))
88 return t[f].val;
89
90 return -1;
91 }
92
93 struct vary *
vary_append(struct vary * v,char * arg)94 vary_append(struct vary *v, char *arg)
95 {
96 struct vary *result, **nextp;
97
98 if (v) {
99 result = v;
100 while (v->next)
101 v = v->next;
102 nextp = &v->next;
103 } else
104 nextp = &result;
105
106 if ((*nextp = (struct vary *)malloc(sizeof(struct vary))) == NULL)
107 exifdie((const char *)strerror(errno));
108 (*nextp)->arg = arg;
109 (*nextp)->next = NULL;
110 return result;
111 }
112
113 static int mdays[12] = { 31, 0, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
114
115 static int
daysinmonth(const struct tm * t)116 daysinmonth(const struct tm *t)
117 {
118 int year;
119
120 year = t->tm_year + 1900;
121
122 if (t->tm_mon == 1)
123 if (!(year % 400))
124 return 29;
125 else if (!(year % 100))
126 return 28;
127 else if (!(year % 4))
128 return 29;
129 else
130 return 28;
131 else if (t->tm_mon >= 0 && t->tm_mon < 12)
132 return mdays[t->tm_mon];
133
134 return 0;
135 }
136
137
138 static int
adjyear(struct tm * t,char type,int val,int mk)139 adjyear(struct tm *t, char type, int val, int mk)
140 {
141 switch (type) {
142 case '+':
143 t->tm_year += val;
144 break;
145 case '-':
146 t->tm_year -= val;
147 break;
148 default:
149 t->tm_year = val;
150 if (t->tm_year < 69)
151 t->tm_year += 100; /* as per date.c */
152 else if (t->tm_year > 1900)
153 t->tm_year -= 1900; /* struct tm holds years since 1900 */
154 break;
155 }
156 return !mk || domktime(t, type) != -1;
157 }
158
159 static int
adjmon(struct tm * t,char type,int val,int istext,int mk)160 adjmon(struct tm *t, char type, int val, int istext, int mk)
161 {
162 if (val < 0)
163 return 0;
164
165 switch (type) {
166 case '+':
167 if (istext) {
168 if (val <= t->tm_mon)
169 val += 11 - t->tm_mon; /* early next year */
170 else
171 val -= t->tm_mon + 1; /* later this year */
172 }
173 if (val) {
174 if (!adjyear(t, '+', (t->tm_mon + val) / 12, 0))
175 return 0;
176 val %= 12;
177 t->tm_mon += val;
178 if (t->tm_mon > 11)
179 t->tm_mon -= 12;
180 }
181 break;
182
183 case '-':
184 if (istext) {
185 if (val-1 > t->tm_mon)
186 val = 13 - val + t->tm_mon; /* later last year */
187 else
188 val = t->tm_mon - val + 1; /* early this year */
189 }
190 if (val) {
191 if (!adjyear(t, '-', val / 12, 0))
192 return 0;
193 val %= 12;
194 if (val > t->tm_mon) {
195 if (!adjyear(t, '-', 1, 0))
196 return 0;
197 val -= 12;
198 }
199 t->tm_mon -= val;
200 }
201 break;
202
203 default:
204 if (val > 12 || val < 1)
205 return 0;
206 t->tm_mon = --val;
207 }
208
209 return !mk || domktime(t, type) != -1;
210 }
211
212 static int
adjday(struct tm * t,char type,int val,int mk)213 adjday(struct tm *t, char type, int val, int mk)
214 {
215 int lmdays;
216
217 switch (type) {
218 case '+':
219 while (val) {
220 lmdays = daysinmonth(t);
221 if (val > lmdays - t->tm_mday) {
222 val -= lmdays - t->tm_mday + 1;
223 t->tm_mday = 1;
224 if (!adjmon(t, '+', 1, 0, 0))
225 return 0;
226 } else {
227 t->tm_mday += val;
228 val = 0;
229 }
230 }
231 break;
232 case '-':
233 while (val)
234 if (val >= t->tm_mday) {
235 val -= t->tm_mday;
236 t->tm_mday = 1;
237 if (!adjmon(t, '-', 1, 0, 0))
238 return 0;
239 t->tm_mday = daysinmonth(t);
240 } else {
241 t->tm_mday -= val;
242 val = 0;
243 }
244 break;
245 default:
246 if (val > 0 && val <= daysinmonth(t))
247 t->tm_mday = val;
248 else
249 return 0;
250 break;
251 }
252
253 return !mk || domktime(t, type) != -1;
254 }
255
256 static int
adjwday(struct tm * t,char type,int val,int istext,int mk)257 adjwday(struct tm *t, char type, int val, int istext, int mk)
258 {
259 if (val < 0)
260 return 0;
261
262 switch (type) {
263 case '+':
264 if (istext)
265 if (val < t->tm_wday)
266 val = 7 - t->tm_wday + val; /* early next week */
267 else
268 val -= t->tm_wday; /* later this week */
269 else
270 val *= 7; /* "-v+5w" == "5 weeks in the future" */
271 return !val || adjday(t, '+', val, mk);
272 case '-':
273 if (istext) {
274 if (val > t->tm_wday)
275 val = 7 - val + t->tm_wday; /* later last week */
276 else
277 val = t->tm_wday - val; /* early this week */
278 } else
279 val *= 7; /* "-v-5w" == "5 weeks ago" */
280 return !val || adjday(t, '-', val, mk);
281 default:
282 if (val < t->tm_wday)
283 return adjday(t, '-', t->tm_wday - val, mk);
284 else if (val > 6)
285 return 0;
286 else if (val > t->tm_wday)
287 return adjday(t, '+', val - t->tm_wday, mk);
288 }
289 return 1;
290 }
291
292 static int
adjhour(struct tm * t,char type,int val,int mk)293 adjhour(struct tm *t, char type, int val, int mk)
294 {
295 if (val < 0)
296 return 0;
297
298 switch (type) {
299 case '+':
300 if (val) {
301 int days;
302
303 days = (t->tm_hour + val) / 24;
304 val %= 24;
305 t->tm_hour += val;
306 t->tm_hour %= 24;
307 if (!adjday(t, '+', days, 0))
308 return 0;
309 }
310 break;
311
312 case '-':
313 if (val) {
314 int days;
315
316 days = val / 24;
317 val %= 24;
318 if (val > t->tm_hour) {
319 days++;
320 val -= 24;
321 }
322 t->tm_hour -= val;
323 if (!adjday(t, '-', days, 0))
324 return 0;
325 }
326 break;
327
328 default:
329 if (val > 23)
330 return 0;
331 t->tm_hour = val;
332 }
333
334 return !mk || domktime(t, type) != -1;
335 }
336
337 static int
adjmin(struct tm * t,char type,int val,int mk)338 adjmin(struct tm *t, char type, int val, int mk)
339 {
340 if (val < 0)
341 return 0;
342
343 switch (type) {
344 case '+':
345 if (val) {
346 if (!adjhour(t, '+', (t->tm_min + val) / 60, 0))
347 return 0;
348 val %= 60;
349 t->tm_min += val;
350 if (t->tm_min > 59)
351 t->tm_min -= 60;
352 }
353 break;
354
355 case '-':
356 if (val) {
357 if (!adjhour(t, '-', val / 60, 0))
358 return 0;
359 val %= 60;
360 if (val > t->tm_min) {
361 if (!adjhour(t, '-', 1, 0))
362 return 0;
363 val -= 60;
364 }
365 t->tm_min -= val;
366 }
367 break;
368
369 default:
370 if (val > 59)
371 return 0;
372 t->tm_min = val;
373 }
374
375 return !mk || domktime(t, type) != -1;
376 }
377
378 static int
adjsec(struct tm * t,char type,int val,int mk)379 adjsec(struct tm *t, char type, int val, int mk)
380 {
381 if (val < 0)
382 return 0;
383
384 switch (type) {
385 case '+':
386 if (val) {
387 if (!adjmin(t, '+', (t->tm_sec + val) / 60, 0))
388 return 0;
389 val %= 60;
390 t->tm_sec += val;
391 if (t->tm_sec > 59)
392 t->tm_sec -= 60;
393 }
394 break;
395
396 case '-':
397 if (val) {
398 if (!adjmin(t, '-', val / 60, 0))
399 return 0;
400 val %= 60;
401 if (val > t->tm_sec) {
402 if (!adjmin(t, '-', 1, 0))
403 return 0;
404 val -= 60;
405 }
406 t->tm_sec -= val;
407 }
408 break;
409
410 default:
411 if (val > 59)
412 return 0;
413 t->tm_sec = val;
414 }
415
416 return !mk || domktime(t, type) != -1;
417 }
418
419 const struct vary *
vary_apply(const struct vary * v,struct tm * t)420 vary_apply(const struct vary *v, struct tm *t)
421 {
422 char type;
423 char which;
424 char *arg;
425 size_t len;
426 int val;
427
428 /* Ignore effects of DST. */
429 t->tm_isdst = -1;
430
431 for (; v; v = v->next) {
432 type = *v->arg;
433 arg = v->arg;
434 if (type == '+' || type == '-')
435 arg++;
436 else
437 type = '\0';
438 len = strlen(arg);
439 if (len < 2)
440 return v;
441
442 if (strspn(arg, digits) != len-1) {
443 val = trans(trans_wday, arg);
444 if (val != -1) {
445 if (!adjwday(t, type, val, 1, 1))
446 return v;
447 } else {
448 val = trans(trans_mon, arg);
449 if (val != -1) {
450 if (!adjmon(t, type, val, 1, 1))
451 return v;
452 } else
453 return v;
454 }
455 } else {
456 val = atoi(arg);
457 which = arg[len-1];
458
459 switch (which) {
460 case 'S':
461 if (!adjsec(t, type, val, 1))
462 return v;
463 break;
464 case 'M':
465 if (!adjmin(t, type, val, 1))
466 return v;
467 break;
468 case 'H':
469 if (!adjhour(t, type, val, 1))
470 return v;
471 break;
472 case 'd':
473 if (!adjday(t, type, val, 1))
474 return v;
475 break;
476 case 'w':
477 if (!adjwday(t, type, val, 0, 1))
478 return v;
479 break;
480 case 'm':
481 if (!adjmon(t, type, val, 0, 1))
482 return v;
483 break;
484 case 'y':
485 if (!adjyear(t, type, val, 1))
486 return v;
487 break;
488 default:
489 return v;
490 }
491 }
492 }
493 return 0;
494 }
495
496 void
vary_destroy(struct vary * v)497 vary_destroy(struct vary *v)
498 {
499 struct vary *n;
500
501 while (v) {
502 n = v->next;
503 free(v);
504 v = n;
505 }
506 }
507