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 __FBSDID("$FreeBSD$"); 29 30 #include <err.h> 31 #include <time.h> 32 #include <string.h> 33 #include <stdlib.h> 34 #include "vary.h" 35 36 struct trans { 37 int val; 38 const char *str; 39 }; 40 41 static struct trans trans_mon[] = { 42 { 1, "january" }, { 2, "february" }, { 3, "march" }, { 4, "april" }, 43 { 5, "may"}, { 6, "june" }, { 7, "july" }, { 8, "august" }, 44 { 9, "september" }, { 10, "october" }, { 11, "november" }, { 12, "december" }, 45 { -1, NULL } 46 }; 47 48 static struct trans trans_wday[] = { 49 { 0, "sunday" }, { 1, "monday" }, { 2, "tuesday" }, { 3, "wednesday" }, 50 { 4, "thursday" }, { 5, "friday" }, { 6, "saturday" }, 51 { -1, NULL } 52 }; 53 54 static char digits[] = "0123456789"; 55 static int adjhour(struct tm *, char, int, int); 56 57 static int 58 domktime(struct tm *t, char type) 59 { 60 time_t ret; 61 62 while ((ret = mktime(t)) == -1 && t->tm_year > 68 && t->tm_year < 138) 63 /* While mktime() fails, adjust by an hour */ 64 adjhour(t, type == '-' ? type : '+', 1, 0); 65 66 return ret; 67 } 68 69 static int 70 trans(const struct trans t[], const char *arg) 71 { 72 int f; 73 74 for (f = 0; t[f].val != -1; f++) 75 if (!strncasecmp(t[f].str, arg, 3) || 76 !strncasecmp(t[f].str, arg, strlen(t[f].str))) 77 return t[f].val; 78 79 return -1; 80 } 81 82 struct vary * 83 vary_append(struct vary *v, char *arg) 84 { 85 struct vary *result, **nextp; 86 87 if (v) { 88 result = v; 89 while (v->next) 90 v = v->next; 91 nextp = &v->next; 92 } else 93 nextp = &result; 94 95 if ((*nextp = (struct vary *)malloc(sizeof(struct vary))) == NULL) 96 err(1, "malloc"); 97 (*nextp)->arg = arg; 98 (*nextp)->next = NULL; 99 return result; 100 } 101 102 static int mdays[12] = { 31, 0, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }; 103 104 static int 105 daysinmonth(const struct tm *t) 106 { 107 int year; 108 109 year = t->tm_year + 1900; 110 111 if (t->tm_mon == 1) 112 if (!(year % 400)) 113 return 29; 114 else if (!(year % 100)) 115 return 28; 116 else if (!(year % 4)) 117 return 29; 118 else 119 return 28; 120 else if (t->tm_mon >= 0 && t->tm_mon < 12) 121 return mdays[t->tm_mon]; 122 123 return 0; 124 } 125 126 127 static int 128 adjyear(struct tm *t, char type, int val, int mk) 129 { 130 switch (type) { 131 case '+': 132 t->tm_year += val; 133 break; 134 case '-': 135 t->tm_year -= val; 136 break; 137 default: 138 t->tm_year = val; 139 if (t->tm_year < 69) 140 t->tm_year += 100; /* as per date.c */ 141 else if (t->tm_year > 1900) 142 t->tm_year -= 1900; /* struct tm holds years since 1900 */ 143 break; 144 } 145 return !mk || domktime(t, type) != -1; 146 } 147 148 static int 149 adjmon(struct tm *t, char type, int val, int istext, int mk) 150 { 151 int lmdays; 152 153 if (val < 0) 154 return 0; 155 156 switch (type) { 157 case '+': 158 if (istext) { 159 if (val <= t->tm_mon) 160 val += 11 - t->tm_mon; /* early next year */ 161 else 162 val -= t->tm_mon + 1; /* later this year */ 163 } 164 if (val) { 165 if (!adjyear(t, '+', (t->tm_mon + val) / 12, 0)) 166 return 0; 167 val %= 12; 168 t->tm_mon += val; 169 if (t->tm_mon > 11) 170 t->tm_mon -= 12; 171 } 172 break; 173 174 case '-': 175 if (istext) { 176 if (val-1 > t->tm_mon) 177 val = 13 - val + t->tm_mon; /* later last year */ 178 else 179 val = t->tm_mon - val + 1; /* early this year */ 180 } 181 if (val) { 182 if (!adjyear(t, '-', val / 12, 0)) 183 return 0; 184 val %= 12; 185 if (val > t->tm_mon) { 186 if (!adjyear(t, '-', 1, 0)) 187 return 0; 188 val -= 12; 189 } 190 t->tm_mon -= val; 191 } 192 break; 193 194 default: 195 if (val > 12 || val < 1) 196 return 0; 197 t->tm_mon = --val; 198 } 199 200 /* e.g., -v-1m on March, 31 is the last day of February in common sense */ 201 lmdays = daysinmonth(t); 202 if (t->tm_mday > lmdays) 203 t->tm_mday = lmdays; 204 205 return !mk || domktime(t, type) != -1; 206 } 207 208 static int 209 adjday(struct tm *t, char type, int val, int mk) 210 { 211 int lmdays; 212 213 switch (type) { 214 case '+': 215 while (val) { 216 lmdays = daysinmonth(t); 217 if (val > lmdays - t->tm_mday) { 218 val -= lmdays - t->tm_mday + 1; 219 t->tm_mday = 1; 220 if (!adjmon(t, '+', 1, 0, 0)) 221 return 0; 222 } else { 223 t->tm_mday += val; 224 val = 0; 225 } 226 } 227 break; 228 case '-': 229 while (val) 230 if (val >= t->tm_mday) { 231 val -= t->tm_mday; 232 t->tm_mday = 1; 233 if (!adjmon(t, '-', 1, 0, 0)) 234 return 0; 235 t->tm_mday = daysinmonth(t); 236 } else { 237 t->tm_mday -= val; 238 val = 0; 239 } 240 break; 241 default: 242 if (val > 0 && val <= daysinmonth(t)) 243 t->tm_mday = val; 244 else 245 return 0; 246 break; 247 } 248 249 return !mk || domktime(t, type) != -1; 250 } 251 252 static int 253 adjwday(struct tm *t, char type, int val, int istext, int mk) 254 { 255 if (val < 0) 256 return 0; 257 258 switch (type) { 259 case '+': 260 if (istext) 261 if (val < t->tm_wday) 262 val = 7 - t->tm_wday + val; /* early next week */ 263 else 264 val -= t->tm_wday; /* later this week */ 265 else 266 val *= 7; /* "-v+5w" == "5 weeks in the future" */ 267 return !val || adjday(t, '+', val, mk); 268 case '-': 269 if (istext) { 270 if (val > t->tm_wday) 271 val = 7 - val + t->tm_wday; /* later last week */ 272 else 273 val = t->tm_wday - val; /* early this week */ 274 } else 275 val *= 7; /* "-v-5w" == "5 weeks ago" */ 276 return !val || adjday(t, '-', val, mk); 277 default: 278 if (val < t->tm_wday) 279 return adjday(t, '-', t->tm_wday - val, mk); 280 else if (val > 6) 281 return 0; 282 else if (val > t->tm_wday) 283 return adjday(t, '+', val - t->tm_wday, mk); 284 } 285 return 1; 286 } 287 288 static int 289 adjhour(struct tm *t, char type, int val, int mk) 290 { 291 if (val < 0) 292 return 0; 293 294 switch (type) { 295 case '+': 296 if (val) { 297 int days; 298 299 days = (t->tm_hour + val) / 24; 300 val %= 24; 301 t->tm_hour += val; 302 t->tm_hour %= 24; 303 if (!adjday(t, '+', days, 0)) 304 return 0; 305 } 306 break; 307 308 case '-': 309 if (val) { 310 int days; 311 312 days = val / 24; 313 val %= 24; 314 if (val > t->tm_hour) { 315 days++; 316 val -= 24; 317 } 318 t->tm_hour -= val; 319 if (!adjday(t, '-', days, 0)) 320 return 0; 321 } 322 break; 323 324 default: 325 if (val > 23) 326 return 0; 327 t->tm_hour = val; 328 } 329 330 return !mk || domktime(t, type) != -1; 331 } 332 333 static int 334 adjmin(struct tm *t, char type, int val, int mk) 335 { 336 if (val < 0) 337 return 0; 338 339 switch (type) { 340 case '+': 341 if (val) { 342 if (!adjhour(t, '+', (t->tm_min + val) / 60, 0)) 343 return 0; 344 val %= 60; 345 t->tm_min += val; 346 if (t->tm_min > 59) 347 t->tm_min -= 60; 348 } 349 break; 350 351 case '-': 352 if (val) { 353 if (!adjhour(t, '-', val / 60, 0)) 354 return 0; 355 val %= 60; 356 if (val > t->tm_min) { 357 if (!adjhour(t, '-', 1, 0)) 358 return 0; 359 val -= 60; 360 } 361 t->tm_min -= val; 362 } 363 break; 364 365 default: 366 if (val > 59) 367 return 0; 368 t->tm_min = val; 369 } 370 371 return !mk || domktime(t, type) != -1; 372 } 373 374 static int 375 adjsec(struct tm *t, char type, int val, int mk) 376 { 377 if (val < 0) 378 return 0; 379 380 switch (type) { 381 case '+': 382 if (val) { 383 if (!adjmin(t, '+', (t->tm_sec + val) / 60, 0)) 384 return 0; 385 val %= 60; 386 t->tm_sec += val; 387 if (t->tm_sec > 59) 388 t->tm_sec -= 60; 389 } 390 break; 391 392 case '-': 393 if (val) { 394 if (!adjmin(t, '-', val / 60, 0)) 395 return 0; 396 val %= 60; 397 if (val > t->tm_sec) { 398 if (!adjmin(t, '-', 1, 0)) 399 return 0; 400 val -= 60; 401 } 402 t->tm_sec -= val; 403 } 404 break; 405 406 default: 407 if (val > 59) 408 return 0; 409 t->tm_sec = val; 410 } 411 412 return !mk || domktime(t, type) != -1; 413 } 414 415 const struct vary * 416 vary_apply(const struct vary *v, struct tm *t) 417 { 418 char type; 419 char which; 420 char *arg; 421 size_t len; 422 int val; 423 424 for (; v; v = v->next) { 425 type = *v->arg; 426 arg = v->arg; 427 if (type == '+' || type == '-') 428 arg++; 429 else 430 type = '\0'; 431 len = strlen(arg); 432 if (len < 2) 433 return v; 434 435 if (type == '\0') 436 t->tm_isdst = -1; 437 438 if (strspn(arg, digits) != len-1) { 439 val = trans(trans_wday, arg); 440 if (val != -1) { 441 if (!adjwday(t, type, val, 1, 1)) 442 return v; 443 } else { 444 val = trans(trans_mon, arg); 445 if (val != -1) { 446 if (!adjmon(t, type, val, 1, 1)) 447 return v; 448 } else 449 return v; 450 } 451 } else { 452 val = atoi(arg); 453 which = arg[len-1]; 454 455 switch (which) { 456 case 'S': 457 if (!adjsec(t, type, val, 1)) 458 return v; 459 break; 460 case 'M': 461 if (!adjmin(t, type, val, 1)) 462 return v; 463 break; 464 case 'H': 465 if (!adjhour(t, type, val, 1)) 466 return v; 467 break; 468 case 'd': 469 t->tm_isdst = -1; 470 if (!adjday(t, type, val, 1)) 471 return v; 472 break; 473 case 'w': 474 t->tm_isdst = -1; 475 if (!adjwday(t, type, val, 0, 1)) 476 return v; 477 break; 478 case 'm': 479 t->tm_isdst = -1; 480 if (!adjmon(t, type, val, 0, 1)) 481 return v; 482 break; 483 case 'y': 484 t->tm_isdst = -1; 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 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