1 /* $OpenBSD: parsetime.c,v 1.27 2019/02/16 15:23:33 naddy 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 40 #include <err.h> 41 #include <errno.h> 42 #include <ctype.h> 43 #include <stdio.h> 44 #include <stdlib.h> 45 #include <string.h> 46 #include <time.h> 47 #include <unistd.h> 48 49 #include "globals.h" 50 #include "at.h" 51 52 /* Structures and unions */ 53 54 enum { /* symbols */ 55 MIDNIGHT, NOON, TEATIME, 56 PM, AM, TOMORROW, TODAY, NOW, 57 MINUTES, HOURS, DAYS, WEEKS, MONTHS, YEARS, 58 NUMBER, NEXT, PLUS, DOT, SLASH, ID, JUNK, 59 JAN, FEB, MAR, APR, MAY, JUN, 60 JUL, AUG, SEP, OCT, NOV, DEC, 61 SUN, MON, TUE, WED, THU, FRI, SAT 62 }; 63 64 /* 65 * parse translation table - table driven parsers can be your FRIEND! 66 */ 67 struct { 68 char *name; /* token name */ 69 int value; /* token id */ 70 int plural; /* is this plural? */ 71 } Specials[] = { 72 { "midnight", MIDNIGHT, 0 }, /* 00:00:00 of today or tomorrow */ 73 { "noon", NOON, 0 }, /* 12:00:00 of today or tomorrow */ 74 { "teatime", TEATIME, 0 }, /* 16:00:00 of today or tomorrow */ 75 { "am", AM, 0 }, /* morning times for 0-12 clock */ 76 { "pm", PM, 0 }, /* evening times for 0-12 clock */ 77 { "tomorrow", TOMORROW, 0 }, /* execute 24 hours from time */ 78 { "today", TODAY, 0 }, /* execute today - don't advance time */ 79 { "now", NOW, 0 }, /* opt prefix for PLUS */ 80 { "next", NEXT, 0 }, /* opt prefix for + 1 */ 81 82 { "minute", MINUTES, 0 }, /* minutes multiplier */ 83 { "min", MINUTES, 0 }, 84 { "m", MINUTES, 0 }, 85 { "minutes", MINUTES, 1 }, /* (pluralized) */ 86 { "hour", HOURS, 0 }, /* hours ... */ 87 { "hr", HOURS, 0 }, /* abbreviated */ 88 { "h", HOURS, 0 }, 89 { "hours", HOURS, 1 }, /* (pluralized) */ 90 { "day", DAYS, 0 }, /* days ... */ 91 { "d", DAYS, 0 }, 92 { "days", DAYS, 1 }, /* (pluralized) */ 93 { "week", WEEKS, 0 }, /* week ... */ 94 { "w", WEEKS, 0 }, 95 { "weeks", WEEKS, 1 }, /* (pluralized) */ 96 { "month", MONTHS, 0 }, /* month ... */ 97 { "mo", MONTHS, 0 }, 98 { "mth", MONTHS, 0 }, 99 { "months", MONTHS, 1 }, /* (pluralized) */ 100 { "year", YEARS, 0 }, /* year ... */ 101 { "y", YEARS, 0 }, 102 { "years", YEARS, 1 }, /* (pluralized) */ 103 { "jan", JAN, 0 }, 104 { "feb", FEB, 0 }, 105 { "mar", MAR, 0 }, 106 { "apr", APR, 0 }, 107 { "may", MAY, 0 }, 108 { "jun", JUN, 0 }, 109 { "jul", JUL, 0 }, 110 { "aug", AUG, 0 }, 111 { "sep", SEP, 0 }, 112 { "oct", OCT, 0 }, 113 { "nov", NOV, 0 }, 114 { "dec", DEC, 0 }, 115 { "january", JAN,0 }, 116 { "february", FEB,0 }, 117 { "march", MAR,0 }, 118 { "april", APR,0 }, 119 { "may", MAY,0 }, 120 { "june", JUN,0 }, 121 { "july", JUL,0 }, 122 { "august", AUG,0 }, 123 { "september", SEP,0 }, 124 { "october", OCT,0 }, 125 { "november", NOV,0 }, 126 { "december", DEC,0 }, 127 { "sunday", SUN, 0 }, 128 { "sun", SUN, 0 }, 129 { "monday", MON, 0 }, 130 { "mon", MON, 0 }, 131 { "tuesday", TUE, 0 }, 132 { "tue", TUE, 0 }, 133 { "wednesday", WED, 0 }, 134 { "wed", WED, 0 }, 135 { "thursday", THU, 0 }, 136 { "thu", THU, 0 }, 137 { "friday", FRI, 0 }, 138 { "fri", FRI, 0 }, 139 { "saturday", SAT, 0 }, 140 { "sat", SAT, 0 }, 141 }; 142 143 static char **scp; /* scanner - pointer at arglist */ 144 static int scc; /* scanner - count of remaining arguments */ 145 static char *sct; /* scanner - next char pointer in current argument */ 146 static int need; /* scanner - need to advance to next argument */ 147 static char *sc_token; /* scanner - token buffer */ 148 static size_t sc_len; /* scanner - length of token buffer */ 149 static int sc_tokid; /* scanner - token id */ 150 static int sc_tokplur; /* scanner - is token plural? */ 151 152 /* 153 * parse a token, checking if it's something special to us 154 */ 155 static int 156 parse_token(char *arg) 157 { 158 int i; 159 160 for (i=0; i < sizeof(Specials) / sizeof(Specials[0]); i++) { 161 if (strcasecmp(Specials[i].name, arg) == 0) { 162 sc_tokplur = Specials[i].plural; 163 return (sc_tokid = Specials[i].value); 164 } 165 } 166 167 /* not special - must be some random id */ 168 return (ID); 169 } 170 171 172 /* 173 * init_scanner() sets up the scanner to eat arguments 174 */ 175 static int 176 init_scanner(int argc, char **argv) 177 { 178 scp = argv; 179 scc = argc; 180 need = 1; 181 sc_len = 1; 182 while (argc-- > 0) 183 sc_len += strlen(*argv++); 184 185 if ((sc_token = malloc(sc_len)) == NULL) { 186 warn(NULL); 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 warnx("%s time", (tok == EOF) ? "incomplete" : "garbled"); 269 } 270 271 272 /* 273 * expect() gets a token and returns -1 if it's not the token we want 274 */ 275 static int 276 expect(int desired) 277 { 278 if (token() != desired) { 279 plonk(sc_tokid); 280 return (-1); 281 } 282 return (0); 283 } 284 285 286 /* 287 * dateadd() adds a number of minutes to a date. It is extraordinarily 288 * stupid regarding day-of-month overflow, and will most likely not 289 * work properly 290 */ 291 static void 292 dateadd(int minutes, struct tm *tm) 293 { 294 /* increment days */ 295 296 while (minutes > 24*60) { 297 minutes -= 24*60; 298 tm->tm_mday++; 299 } 300 301 /* increment hours */ 302 while (minutes > 60) { 303 minutes -= 60; 304 tm->tm_hour++; 305 if (tm->tm_hour > 23) { 306 tm->tm_mday++; 307 tm->tm_hour = 0; 308 } 309 } 310 311 /* increment minutes */ 312 tm->tm_min += minutes; 313 314 if (tm->tm_min > 59) { 315 tm->tm_hour++; 316 tm->tm_min -= 60; 317 318 if (tm->tm_hour > 23) { 319 tm->tm_mday++; 320 tm->tm_hour = 0; 321 } 322 } 323 } 324 325 326 /* 327 * plus() parses a now + time 328 * 329 * at [NOW] PLUS NUMBER [MINUTES|HOURS|DAYS|WEEKS|MONTHS|YEARS] 330 * 331 */ 332 static int 333 plus(struct tm *tm) 334 { 335 int increment; 336 int expectplur; 337 338 if (sc_tokid == NEXT) { 339 increment = 1; 340 expectplur = 0; 341 } else { 342 if (expect(NUMBER) != 0) 343 return (-1); 344 increment = atoi(sc_token); 345 expectplur = (increment != 1) ? 1 : 0; 346 } 347 348 switch (token()) { 349 case YEARS: 350 tm->tm_year += increment; 351 return (0); 352 case MONTHS: 353 tm->tm_mon += increment; 354 while (tm->tm_mon >= 12) { 355 tm->tm_year++; 356 tm->tm_mon -= 12; 357 } 358 return (0); 359 case WEEKS: 360 increment *= 7; 361 /* FALLTHROUGH */ 362 case DAYS: 363 increment *= 24; 364 /* FALLTHROUGH */ 365 case HOURS: 366 increment *= 60; 367 /* FALLTHROUGH */ 368 case MINUTES: 369 if (expectplur != sc_tokplur) 370 warnx("pluralization is wrong"); 371 dateadd(increment, tm); 372 return (0); 373 } 374 375 plonk(sc_tokid); 376 return (-1); 377 } 378 379 380 /* 381 * tod() computes the time of day 382 * [NUMBER [DOT NUMBER] [AM|PM]] 383 */ 384 static int 385 tod(struct tm *tm) 386 { 387 int hour, minute = 0; 388 size_t tlen; 389 390 hour = atoi(sc_token); 391 tlen = strlen(sc_token); 392 393 /* 394 * first pick out the time of day - if it's 4 digits, we assume 395 * a HHMM time, otherwise it's HH DOT MM time 396 */ 397 if (token() == DOT) { 398 if (expect(NUMBER) != 0) 399 return (-1); 400 minute = atoi(sc_token); 401 if (minute > 59) 402 goto bad; 403 token(); 404 } else if (tlen == 4) { 405 minute = hour % 100; 406 if (minute > 59) 407 goto bad; 408 hour = hour / 100; 409 } 410 411 /* 412 * check if an AM or PM specifier was given 413 */ 414 if (sc_tokid == AM || sc_tokid == PM) { 415 if (hour > 12) 416 goto bad; 417 418 if (sc_tokid == PM) { 419 if (hour != 12) /* 12:xx PM is 12:xx, not 24:xx */ 420 hour += 12; 421 } else { 422 if (hour == 12) /* 12:xx AM is 00:xx, not 12:xx */ 423 hour = 0; 424 } 425 token(); 426 } else if (hour > 23) 427 goto bad; 428 429 /* 430 * if we specify an absolute time, we don't want to bump the day even 431 * if we've gone past that time - but if we're specifying a time plus 432 * a relative offset, it's okay to bump things 433 */ 434 if ((sc_tokid == EOF || sc_tokid == PLUS || sc_tokid == NEXT) && 435 (tm->tm_hour > hour || 436 (tm->tm_hour == hour && tm->tm_min > minute))) { 437 tm->tm_mday++; 438 tm->tm_wday++; 439 } 440 441 tm->tm_hour = hour; 442 tm->tm_min = minute; 443 if (tm->tm_hour == 24) { 444 tm->tm_hour = 0; 445 tm->tm_mday++; 446 } 447 return (0); 448 bad: 449 warnx("garbled time"); 450 return (-1); 451 } 452 453 454 /* 455 * assign_date() assigns a date, wrapping to next year if needed 456 */ 457 static void 458 assign_date(struct tm *tm, int mday, int mon, int year) 459 { 460 461 /* 462 * Convert year into tm_year format (year - 1900). 463 * We may be given the year in 2 digit, 4 digit, or tm_year format. 464 */ 465 if (year != -1) { 466 if (year >= 1900) 467 year -= 1900; /* convert from 4 digit year */ 468 else if (year < 100) { 469 /* Convert to tm_year assuming current century */ 470 year += (tm->tm_year / 100) * 100; 471 472 if (year == tm->tm_year - 1) 473 year++; /* Common off by one error */ 474 else if (year < tm->tm_year) 475 year += 100; /* must be in next century */ 476 } 477 } 478 479 if (year < 0 && 480 (tm->tm_mon > mon ||(tm->tm_mon == mon && tm->tm_mday > mday))) 481 year = tm->tm_year + 1; 482 483 tm->tm_mday = mday; 484 tm->tm_mon = mon; 485 486 if (year >= 0) 487 tm->tm_year = year; 488 } 489 490 491 /* 492 * month() picks apart a month specification 493 * 494 * /[<month> NUMBER [NUMBER]] \ 495 * |[TOMORROW] | 496 * |[DAY OF WEEK] | 497 * |NUMBER [SLASH NUMBER [SLASH NUMBER]]| 498 * \PLUS NUMBER MINUTES|HOURS|DAYS|WEEKS|MONTHS|YEARS/ 499 */ 500 static int 501 month(struct tm *tm) 502 { 503 int year = (-1); 504 int mday, wday, mon; 505 size_t tlen; 506 507 switch (sc_tokid) { 508 case NEXT: 509 case PLUS: 510 if (plus(tm) != 0) 511 return (-1); 512 break; 513 514 case TOMORROW: 515 /* do something tomorrow */ 516 tm->tm_mday++; 517 tm->tm_wday++; 518 case TODAY: 519 /* force ourselves to stay in today - no further processing */ 520 token(); 521 break; 522 523 case JAN: case FEB: case MAR: case APR: case MAY: case JUN: 524 case JUL: case AUG: case SEP: case OCT: case NOV: case DEC: 525 /* 526 * do month mday [year] 527 */ 528 mon = sc_tokid - JAN; 529 if (expect(NUMBER) != 0) 530 return (-1); 531 mday = atoi(sc_token); 532 if (token() == NUMBER) { 533 year = atoi(sc_token); 534 token(); 535 } 536 assign_date(tm, mday, mon, year); 537 break; 538 539 case SUN: case MON: case TUE: 540 case WED: case THU: case FRI: 541 case SAT: 542 /* do a particular day of the week */ 543 wday = sc_tokid - SUN; 544 545 mday = tm->tm_mday; 546 547 /* if this day is < today, then roll to next week */ 548 if (wday < tm->tm_wday) 549 mday += 7 - (tm->tm_wday - wday); 550 else 551 mday += (wday - tm->tm_wday); 552 553 tm->tm_wday = wday; 554 555 assign_date(tm, mday, tm->tm_mon, tm->tm_year); 556 break; 557 558 case NUMBER: 559 /* 560 * get numeric MMDDYY, mm/dd/yy, or dd.mm.yy 561 */ 562 tlen = strlen(sc_token); 563 mon = atoi(sc_token); 564 token(); 565 566 if (sc_tokid == SLASH || sc_tokid == DOT) { 567 int sep; 568 569 sep = sc_tokid; 570 if (expect(NUMBER) != 0) 571 return (-1); 572 mday = atoi(sc_token); 573 if (token() == sep) { 574 if (expect(NUMBER) != 0) 575 return (-1); 576 year = atoi(sc_token); 577 token(); 578 } 579 580 /* 581 * flip months and days for european timing 582 */ 583 if (sep == DOT) { 584 int x = mday; 585 mday = mon; 586 mon = x; 587 } 588 } else if (tlen == 6 || tlen == 8) { 589 if (tlen == 8) { 590 year = (mon % 10000) - 1900; 591 mon /= 10000; 592 } else { 593 year = mon % 100; 594 mon /= 100; 595 } 596 mday = mon % 100; 597 mon /= 100; 598 } else 599 goto bad; 600 601 mon--; 602 if (mon < 0 || mon > 11 || mday < 1 || mday > 31) 603 goto bad; 604 605 assign_date(tm, mday, mon, year); 606 break; 607 } 608 return (0); 609 bad: 610 warnx("garbled time"); 611 return (-1); 612 } 613 614 615 time_t 616 parsetime(int argc, char **argv) 617 { 618 /* 619 * Do the argument parsing, die if necessary, and return the 620 * time the job should be run. 621 */ 622 time_t nowtimer, runtimer; 623 struct tm nowtime, runtime; 624 int hr = 0; 625 /* this MUST be initialized to zero for midnight/noon/teatime */ 626 627 if (argc == 0) 628 return (-1); 629 630 nowtimer = time(NULL); 631 nowtime = *localtime(&nowtimer); 632 633 runtime = nowtime; 634 runtime.tm_sec = 0; 635 runtime.tm_isdst = 0; 636 637 if (init_scanner(argc, argv) == -1) 638 return (-1); 639 640 switch (token()) { 641 case NOW: /* now is optional prefix for PLUS tree */ 642 token(); 643 if (sc_tokid == EOF) { 644 runtime = nowtime; 645 break; 646 } 647 else if (sc_tokid != PLUS && sc_tokid != NEXT) 648 plonk(sc_tokid); 649 case NEXT: 650 case PLUS: 651 if (plus(&runtime) != 0) 652 return (-1); 653 break; 654 655 case NUMBER: 656 if (tod(&runtime) != 0 || month(&runtime) != 0) 657 return (-1); 658 break; 659 660 /* 661 * evil coding for TEATIME|NOON|MIDNIGHT - we've initialised 662 * hr to zero up above, then fall into this case in such a 663 * way so we add +12 +4 hours to it for teatime, +12 hours 664 * to it for noon, and nothing at all for midnight, then 665 * set our runtime to that hour before leaping into the 666 * month scanner 667 */ 668 case TEATIME: 669 hr += 4; 670 /* FALLTHROUGH */ 671 case NOON: 672 hr += 12; 673 /* FALLTHROUGH */ 674 case MIDNIGHT: 675 if (runtime.tm_hour >= hr) { 676 runtime.tm_mday++; 677 runtime.tm_wday++; 678 } 679 runtime.tm_hour = hr; 680 runtime.tm_min = 0; 681 token(); 682 /* fall through to month setting */ 683 /* FALLTHROUGH */ 684 default: 685 if (month(&runtime) != 0) 686 return (-1); 687 break; 688 } /* ugly case statement */ 689 if (expect(EOF) != 0) 690 return (-1); 691 692 /* 693 * adjust for daylight savings time 694 */ 695 runtime.tm_isdst = -1; 696 runtimer = mktime(&runtime); 697 698 if (runtimer < 0) { 699 warnx("garbled time"); 700 return (-1); 701 } 702 703 if (nowtimer > runtimer) { 704 warnx("cannot schedule jobs in the past"); 705 return (-1); 706 } 707 708 return (runtimer); 709 } 710