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 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 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 * 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 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 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 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 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 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 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 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 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 * 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 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