1 /* $OpenBSD: parsetime.c,v 1.20 2014/01/13 23:18:57 millert Exp $ */ 2 3 /* 4 * parsetime.c - parse time for at(1) 5 * Copyright (C) 1993, 1994 Thomas Koenig 6 * 7 * modifications for english-language times 8 * Copyright (C) 1993 David Parsons 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. The name of the author(s) may not be used to endorse or promote 16 * products derived from this software without specific prior written 17 * permission. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR 20 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 21 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 22 * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT, 23 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 24 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 25 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 26 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 28 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 29 * 30 * at [NOW] PLUS NUMBER MINUTES|HOURS|DAYS|WEEKS|MONTHS|YEARS 31 * /NUMBER [DOT NUMBER] [AM|PM]\ /[MONTH NUMBER [NUMBER]] \ 32 * |NOON | |[TOMORROW] | 33 * |MIDNIGHT | |[DAY OF WEEK] | 34 * \TEATIME / |NUMBER [SLASH NUMBER [SLASH NUMBER]]| 35 * \PLUS NUMBER MINUTES|HOURS|DAYS|WEEKS|MONTHS|YEARS/ 36 */ 37 38 #include <sys/types.h> 39 #include <errno.h> 40 #include <ctype.h> 41 #include <stdio.h> 42 #include <stdlib.h> 43 #include <string.h> 44 #include <time.h> 45 #include <tzfile.h> 46 #include <unistd.h> 47 48 #include "globals.h" 49 #include "at.h" 50 51 /* Structures and unions */ 52 53 enum { /* symbols */ 54 MIDNIGHT, NOON, TEATIME, 55 PM, AM, TOMORROW, TODAY, NOW, 56 MINUTES, HOURS, DAYS, WEEKS, MONTHS, YEARS, 57 NUMBER, NEXT, PLUS, DOT, SLASH, ID, JUNK, 58 JAN, FEB, MAR, APR, MAY, JUN, 59 JUL, AUG, SEP, OCT, NOV, DEC, 60 SUN, MON, TUE, WED, THU, FRI, SAT 61 }; 62 63 /* 64 * parse translation table - table driven parsers can be your FRIEND! 65 */ 66 struct { 67 char *name; /* token name */ 68 int value; /* token id */ 69 int plural; /* is this plural? */ 70 } Specials[] = { 71 { "midnight", MIDNIGHT, 0 }, /* 00:00:00 of today or tomorrow */ 72 { "noon", NOON, 0 }, /* 12:00:00 of today or tomorrow */ 73 { "teatime", TEATIME, 0 }, /* 16:00:00 of today or tomorrow */ 74 { "am", AM, 0 }, /* morning times for 0-12 clock */ 75 { "pm", PM, 0 }, /* evening times for 0-12 clock */ 76 { "tomorrow", TOMORROW, 0 }, /* execute 24 hours from time */ 77 { "today", TODAY, 0 }, /* execute today - don't advance time */ 78 { "now", NOW, 0 }, /* opt prefix for PLUS */ 79 { "next", NEXT, 0 }, /* opt prefix for + 1 */ 80 81 { "minute", MINUTES, 0 }, /* minutes multiplier */ 82 { "min", MINUTES, 0 }, 83 { "m", MINUTES, 0 }, 84 { "minutes", MINUTES, 1 }, /* (pluralized) */ 85 { "hour", HOURS, 0 }, /* hours ... */ 86 { "hr", HOURS, 0 }, /* abbreviated */ 87 { "h", HOURS, 0 }, 88 { "hours", HOURS, 1 }, /* (pluralized) */ 89 { "day", DAYS, 0 }, /* days ... */ 90 { "d", DAYS, 0 }, 91 { "days", DAYS, 1 }, /* (pluralized) */ 92 { "week", WEEKS, 0 }, /* week ... */ 93 { "w", WEEKS, 0 }, 94 { "weeks", WEEKS, 1 }, /* (pluralized) */ 95 { "month", MONTHS, 0 }, /* month ... */ 96 { "mo", MONTHS, 0 }, 97 { "mth", MONTHS, 0 }, 98 { "months", MONTHS, 1 }, /* (pluralized) */ 99 { "year", YEARS, 0 }, /* year ... */ 100 { "y", YEARS, 0 }, 101 { "years", YEARS, 1 }, /* (pluralized) */ 102 { "jan", JAN, 0 }, 103 { "feb", FEB, 0 }, 104 { "mar", MAR, 0 }, 105 { "apr", APR, 0 }, 106 { "may", MAY, 0 }, 107 { "jun", JUN, 0 }, 108 { "jul", JUL, 0 }, 109 { "aug", AUG, 0 }, 110 { "sep", SEP, 0 }, 111 { "oct", OCT, 0 }, 112 { "nov", NOV, 0 }, 113 { "dec", DEC, 0 }, 114 { "january", JAN,0 }, 115 { "february", FEB,0 }, 116 { "march", MAR,0 }, 117 { "april", APR,0 }, 118 { "may", MAY,0 }, 119 { "june", JUN,0 }, 120 { "july", JUL,0 }, 121 { "august", AUG,0 }, 122 { "september", SEP,0 }, 123 { "october", OCT,0 }, 124 { "november", NOV,0 }, 125 { "december", DEC,0 }, 126 { "sunday", SUN, 0 }, 127 { "sun", SUN, 0 }, 128 { "monday", MON, 0 }, 129 { "mon", MON, 0 }, 130 { "tuesday", TUE, 0 }, 131 { "tue", TUE, 0 }, 132 { "wednesday", WED, 0 }, 133 { "wed", WED, 0 }, 134 { "thursday", THU, 0 }, 135 { "thu", THU, 0 }, 136 { "friday", FRI, 0 }, 137 { "fri", FRI, 0 }, 138 { "saturday", SAT, 0 }, 139 { "sat", SAT, 0 }, 140 }; 141 142 static char **scp; /* scanner - pointer at arglist */ 143 static int scc; /* scanner - count of remaining arguments */ 144 static char *sct; /* scanner - next char pointer in current argument */ 145 static int need; /* scanner - need to advance to next argument */ 146 static char *sc_token; /* scanner - token buffer */ 147 static size_t sc_len; /* scanner - length of token buffer */ 148 static int sc_tokid; /* scanner - token id */ 149 static int sc_tokplur; /* scanner - is token plural? */ 150 151 /* 152 * parse a token, checking if it's something special to us 153 */ 154 static int 155 parse_token(char *arg) 156 { 157 int i; 158 159 for (i=0; i < sizeof(Specials) / sizeof(Specials[0]); i++) { 160 if (strcasecmp(Specials[i].name, arg) == 0) { 161 sc_tokplur = Specials[i].plural; 162 return (sc_tokid = Specials[i].value); 163 } 164 } 165 166 /* not special - must be some random id */ 167 return (ID); 168 } 169 170 171 /* 172 * init_scanner() sets up the scanner to eat arguments 173 */ 174 static int 175 init_scanner(int argc, char **argv) 176 { 177 scp = argv; 178 scc = argc; 179 need = 1; 180 sc_len = 1; 181 while (argc-- > 0) 182 sc_len += strlen(*argv++); 183 184 if ((sc_token = (char *) malloc(sc_len)) == NULL) { 185 fprintf(stderr, "%s: Insufficient virtual memory\n", 186 ProgramName); 187 return (-1); 188 } 189 return (0); 190 } 191 192 /* 193 * token() fetches a token from the input stream 194 */ 195 static int 196 token(void) 197 { 198 int idx; 199 200 for (;;) { 201 bzero(sc_token, sc_len); 202 sc_tokid = EOF; 203 sc_tokplur = 0; 204 idx = 0; 205 206 /* 207 * if we need to read another argument, walk along the 208 * argument list; when we fall off the arglist, we'll 209 * just return EOF forever 210 */ 211 if (need) { 212 if (scc < 1) 213 return (sc_tokid); 214 sct = *scp; 215 scp++; 216 scc--; 217 need = 0; 218 } 219 /* 220 * eat whitespace now - if we walk off the end of the argument, 221 * we'll continue, which puts us up at the top of the while loop 222 * to fetch the next argument in 223 */ 224 while (isspace((unsigned char)*sct)) 225 ++sct; 226 if (!*sct) { 227 need = 1; 228 continue; 229 } 230 231 /* 232 * preserve the first character of the new token 233 */ 234 sc_token[0] = *sct++; 235 236 /* 237 * then see what it is 238 */ 239 if (isdigit((unsigned char)sc_token[0])) { 240 while (isdigit((unsigned char)*sct)) 241 sc_token[++idx] = *sct++; 242 sc_token[++idx] = 0; 243 return ((sc_tokid = NUMBER)); 244 } else if (isalpha((unsigned char)sc_token[0])) { 245 while (isalpha((unsigned char)*sct)) 246 sc_token[++idx] = *sct++; 247 sc_token[++idx] = 0; 248 return (parse_token(sc_token)); 249 } 250 else if (sc_token[0] == ':' || sc_token[0] == '.') 251 return ((sc_tokid = DOT)); 252 else if (sc_token[0] == '+') 253 return ((sc_tokid = PLUS)); 254 else if (sc_token[0] == '/') 255 return ((sc_tokid = SLASH)); 256 else 257 return ((sc_tokid = JUNK)); 258 } 259 } 260 261 262 /* 263 * plonk() gives an appropriate error message if a token is incorrect 264 */ 265 static void 266 plonk(int tok) 267 { 268 fprintf(stderr, "%s: %s time\n", ProgramName, 269 (tok == EOF) ? "incomplete" : "garbled"); 270 } 271 272 273 /* 274 * expect() gets a token and returns -1 if it's not the token we want 275 */ 276 static int 277 expect(int desired) 278 { 279 if (token() != desired) { 280 plonk(sc_tokid); 281 return (-1); 282 } 283 return (0); 284 } 285 286 287 /* 288 * dateadd() adds a number of minutes to a date. It is extraordinarily 289 * stupid regarding day-of-month overflow, and will most likely not 290 * work properly 291 */ 292 static void 293 dateadd(int minutes, struct tm *tm) 294 { 295 /* increment days */ 296 297 while (minutes > 24*60) { 298 minutes -= 24*60; 299 tm->tm_mday++; 300 } 301 302 /* increment hours */ 303 while (minutes > 60) { 304 minutes -= 60; 305 tm->tm_hour++; 306 if (tm->tm_hour > 23) { 307 tm->tm_mday++; 308 tm->tm_hour = 0; 309 } 310 } 311 312 /* increment minutes */ 313 tm->tm_min += minutes; 314 315 if (tm->tm_min > 59) { 316 tm->tm_hour++; 317 tm->tm_min -= 60; 318 319 if (tm->tm_hour > 23) { 320 tm->tm_mday++; 321 tm->tm_hour = 0; 322 } 323 } 324 } 325 326 327 /* 328 * plus() parses a now + time 329 * 330 * at [NOW] PLUS NUMBER [MINUTES|HOURS|DAYS|WEEKS|MONTHS|YEARS] 331 * 332 */ 333 static int 334 plus(struct tm *tm) 335 { 336 int increment; 337 int expectplur; 338 339 if (sc_tokid == NEXT) { 340 increment = 1; 341 expectplur = 0; 342 } else { 343 if (expect(NUMBER) != 0) 344 return (-1); 345 increment = atoi(sc_token); 346 expectplur = (increment != 1) ? 1 : 0; 347 } 348 349 switch (token()) { 350 case YEARS: 351 tm->tm_year += increment; 352 return (0); 353 case MONTHS: 354 tm->tm_mon += increment; 355 while (tm->tm_mon >= 12) { 356 tm->tm_year++; 357 tm->tm_mon -= 12; 358 } 359 return (0); 360 case WEEKS: 361 increment *= 7; 362 /* FALLTHROUGH */ 363 case DAYS: 364 increment *= 24; 365 /* FALLTHROUGH */ 366 case HOURS: 367 increment *= 60; 368 /* FALLTHROUGH */ 369 case MINUTES: 370 if (expectplur != sc_tokplur) 371 fprintf(stderr, "%s: pluralization is wrong\n", 372 ProgramName); 373 dateadd(increment, tm); 374 return (0); 375 } 376 377 plonk(sc_tokid); 378 return (-1); 379 } 380 381 382 /* 383 * tod() computes the time of day 384 * [NUMBER [DOT NUMBER] [AM|PM]] 385 */ 386 static int 387 tod(struct tm *tm) 388 { 389 int hour, minute = 0; 390 size_t tlen; 391 392 hour = atoi(sc_token); 393 tlen = strlen(sc_token); 394 395 /* 396 * first pick out the time of day - if it's 4 digits, we assume 397 * a HHMM time, otherwise it's HH DOT MM time 398 */ 399 if (token() == DOT) { 400 if (expect(NUMBER) != 0) 401 return (-1); 402 minute = atoi(sc_token); 403 if (minute > 59) 404 goto bad; 405 token(); 406 } else if (tlen == 4) { 407 minute = hour % 100; 408 if (minute > 59) 409 goto bad; 410 hour = hour / 100; 411 } 412 413 /* 414 * check if an AM or PM specifier was given 415 */ 416 if (sc_tokid == AM || sc_tokid == PM) { 417 if (hour > 12) 418 goto bad; 419 420 if (sc_tokid == PM) { 421 if (hour != 12) /* 12:xx PM is 12:xx, not 24:xx */ 422 hour += 12; 423 } else { 424 if (hour == 12) /* 12:xx AM is 00:xx, not 12:xx */ 425 hour = 0; 426 } 427 token(); 428 } else if (hour > 23) 429 goto bad; 430 431 /* 432 * if we specify an absolute time, we don't want to bump the day even 433 * if we've gone past that time - but if we're specifying a time plus 434 * a relative offset, it's okay to bump things 435 */ 436 if ((sc_tokid == EOF || sc_tokid == PLUS || sc_tokid == NEXT) && 437 tm->tm_hour > hour) { 438 tm->tm_mday++; 439 tm->tm_wday++; 440 } 441 442 tm->tm_hour = hour; 443 tm->tm_min = minute; 444 if (tm->tm_hour == 24) { 445 tm->tm_hour = 0; 446 tm->tm_mday++; 447 } 448 return (0); 449 bad: 450 fprintf(stderr, "%s: garbled time\n", ProgramName); 451 return (-1); 452 } 453 454 455 /* 456 * assign_date() assigns a date, wrapping to next year if needed 457 */ 458 static void 459 assign_date(struct tm *tm, int mday, int mon, int year) 460 { 461 462 /* 463 * Convert year into tm_year format (year - 1900). 464 * We may be given the year in 2 digit, 4 digit, or tm_year format. 465 */ 466 if (year != -1) { 467 if (year >= TM_YEAR_BASE) 468 year -= TM_YEAR_BASE; /* convert from 4 digit year */ 469 else if (year < 100) { 470 /* Convert to tm_year assuming current century */ 471 year += (tm->tm_year / 100) * 100; 472 473 if (year == tm->tm_year - 1) 474 year++; /* Common off by one error */ 475 else if (year < tm->tm_year) 476 year += 100; /* must be in next century */ 477 } 478 } 479 480 if (year < 0 && 481 (tm->tm_mon > mon ||(tm->tm_mon == mon && tm->tm_mday > mday))) 482 year = tm->tm_year + 1; 483 484 tm->tm_mday = mday; 485 tm->tm_mon = mon; 486 487 if (year >= 0) 488 tm->tm_year = year; 489 } 490 491 492 /* 493 * month() picks apart a month specification 494 * 495 * /[<month> NUMBER [NUMBER]] \ 496 * |[TOMORROW] | 497 * |[DAY OF WEEK] | 498 * |NUMBER [SLASH NUMBER [SLASH NUMBER]]| 499 * \PLUS NUMBER MINUTES|HOURS|DAYS|WEEKS|MONTHS|YEARS/ 500 */ 501 static int 502 month(struct tm *tm) 503 { 504 int year = (-1); 505 int mday, wday, mon; 506 size_t tlen; 507 508 switch (sc_tokid) { 509 case NEXT: 510 case PLUS: 511 if (plus(tm) != 0) 512 return (-1); 513 break; 514 515 case TOMORROW: 516 /* do something tomorrow */ 517 tm->tm_mday++; 518 tm->tm_wday++; 519 case TODAY: 520 /* force ourselves to stay in today - no further processing */ 521 token(); 522 break; 523 524 case JAN: case FEB: case MAR: case APR: case MAY: case JUN: 525 case JUL: case AUG: case SEP: case OCT: case NOV: case DEC: 526 /* 527 * do month mday [year] 528 */ 529 mon = sc_tokid - JAN; 530 if (expect(NUMBER) != 0) 531 return (-1); 532 mday = atoi(sc_token); 533 if (token() == NUMBER) { 534 year = atoi(sc_token); 535 token(); 536 } 537 assign_date(tm, mday, mon, year); 538 break; 539 540 case SUN: case MON: case TUE: 541 case WED: case THU: case FRI: 542 case SAT: 543 /* do a particular day of the week */ 544 wday = sc_tokid - SUN; 545 546 mday = tm->tm_mday; 547 548 /* if this day is < today, then roll to next week */ 549 if (wday < tm->tm_wday) 550 mday += 7 - (tm->tm_wday - wday); 551 else 552 mday += (wday - tm->tm_wday); 553 554 tm->tm_wday = wday; 555 556 assign_date(tm, mday, tm->tm_mon, tm->tm_year); 557 break; 558 559 case NUMBER: 560 /* 561 * get numeric MMDDYY, mm/dd/yy, or dd.mm.yy 562 */ 563 tlen = strlen(sc_token); 564 mon = atoi(sc_token); 565 token(); 566 567 if (sc_tokid == SLASH || sc_tokid == DOT) { 568 int sep; 569 570 sep = sc_tokid; 571 if (expect(NUMBER) != 0) 572 return (-1); 573 mday = atoi(sc_token); 574 if (token() == sep) { 575 if (expect(NUMBER) != 0) 576 return (-1); 577 year = atoi(sc_token); 578 token(); 579 } 580 581 /* 582 * flip months and days for european timing 583 */ 584 if (sep == DOT) { 585 int x = mday; 586 mday = mon; 587 mon = x; 588 } 589 } else if (tlen == 6 || tlen == 8) { 590 if (tlen == 8) { 591 year = (mon % 10000) - TM_YEAR_BASE; 592 mon /= 10000; 593 } else { 594 year = mon % 100; 595 mon /= 100; 596 } 597 mday = mon % 100; 598 mon /= 100; 599 } else 600 goto bad; 601 602 mon--; 603 if (mon < 0 || mon > 11 || mday < 1 || mday > 31) 604 goto bad; 605 606 assign_date(tm, mday, mon, year); 607 break; 608 } 609 return (0); 610 bad: 611 fprintf(stderr, "%s: garbled time\n", ProgramName); 612 return (-1); 613 } 614 615 616 time_t 617 parsetime(int argc, char **argv) 618 { 619 /* 620 * Do the argument parsing, die if necessary, and return the 621 * time the job should be run. 622 */ 623 time_t nowtimer, runtimer; 624 struct tm nowtime, runtime; 625 int hr = 0; 626 /* this MUST be initialized to zero for midnight/noon/teatime */ 627 628 if (argc == 0) 629 return (-1); 630 631 nowtimer = time(NULL); 632 nowtime = *localtime(&nowtimer); 633 634 runtime = nowtime; 635 runtime.tm_sec = 0; 636 runtime.tm_isdst = 0; 637 638 if (init_scanner(argc, argv) == -1) 639 return (-1); 640 641 switch (token()) { 642 case NOW: /* now is optional prefix for PLUS tree */ 643 token(); 644 if (sc_tokid == EOF) { 645 runtime = nowtime; 646 break; 647 } 648 else if (sc_tokid != PLUS && sc_tokid != NEXT) 649 plonk(sc_tokid); 650 case NEXT: 651 case PLUS: 652 if (plus(&runtime) != 0) 653 return (-1); 654 break; 655 656 case NUMBER: 657 if (tod(&runtime) != 0 || month(&runtime) != 0) 658 return (-1); 659 break; 660 661 /* 662 * evil coding for TEATIME|NOON|MIDNIGHT - we've initialised 663 * hr to zero up above, then fall into this case in such a 664 * way so we add +12 +4 hours to it for teatime, +12 hours 665 * to it for noon, and nothing at all for midnight, then 666 * set our runtime to that hour before leaping into the 667 * month scanner 668 */ 669 case TEATIME: 670 hr += 4; 671 /* FALLTHROUGH */ 672 case NOON: 673 hr += 12; 674 /* FALLTHROUGH */ 675 case MIDNIGHT: 676 if (runtime.tm_hour >= hr) { 677 runtime.tm_mday++; 678 runtime.tm_wday++; 679 } 680 runtime.tm_hour = hr; 681 runtime.tm_min = 0; 682 token(); 683 /* fall through to month setting */ 684 /* FALLTHROUGH */ 685 default: 686 if (month(&runtime) != 0) 687 return (-1); 688 break; 689 } /* ugly case statement */ 690 if (expect(EOF) != 0) 691 return (-1); 692 693 /* 694 * adjust for daylight savings time 695 */ 696 runtime.tm_isdst = -1; 697 runtimer = mktime(&runtime); 698 if (runtime.tm_isdst > 0) { 699 runtimer -= 3600; 700 runtimer = mktime(&runtime); 701 } 702 703 if (runtimer < 0) { 704 fprintf(stderr, "%s: garbled time\n", ProgramName); 705 return (-1); 706 } 707 708 if (nowtimer > runtimer) { 709 fprintf(stderr, "%s: cannot schedule jobs in the past\n", 710 ProgramName); 711 return (-1); 712 } 713 714 return (runtimer); 715 } 716