parsetime.c revision 1.16
1/* $OpenBSD: parsetime.c,v 1.16 2007/05/23 19:50:28 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, WETHER 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 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/ 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 53enum { /* symbols */ 54 MIDNIGHT, NOON, TEATIME, 55 PM, AM, TOMORROW, TODAY, NOW, 56 MINUTES, HOURS, DAYS, WEEKS, 57 NUMBER, 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 */ 66struct { 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 80 { "minute", MINUTES, 0 }, /* minutes multiplier */ 81 { "min", MINUTES, 0 }, 82 { "m", MINUTES, 0 }, 83 { "minutes", MINUTES, 1 }, /* (pluralized) */ 84 { "hour", HOURS, 0 }, /* hours ... */ 85 { "hr", HOURS, 0 }, /* abbreviated */ 86 { "h", HOURS, 0 }, 87 { "hours", HOURS, 1 }, /* (pluralized) */ 88 { "day", DAYS, 0 }, /* days ... */ 89 { "d", DAYS, 0 }, 90 { "days", DAYS, 1 }, /* (pluralized) */ 91 { "week", WEEKS, 0 }, /* week ... */ 92 { "w", WEEKS, 0 }, 93 { "weeks", WEEKS, 1 }, /* (pluralized) */ 94 { "jan", JAN, 0 }, 95 { "feb", FEB, 0 }, 96 { "mar", MAR, 0 }, 97 { "apr", APR, 0 }, 98 { "may", MAY, 0 }, 99 { "jun", JUN, 0 }, 100 { "jul", JUL, 0 }, 101 { "aug", AUG, 0 }, 102 { "sep", SEP, 0 }, 103 { "oct", OCT, 0 }, 104 { "nov", NOV, 0 }, 105 { "dec", DEC, 0 }, 106 { "january", JAN,0 }, 107 { "february", FEB,0 }, 108 { "march", MAR,0 }, 109 { "april", APR,0 }, 110 { "may", MAY,0 }, 111 { "june", JUN,0 }, 112 { "july", JUL,0 }, 113 { "august", AUG,0 }, 114 { "september", SEP,0 }, 115 { "october", OCT,0 }, 116 { "november", NOV,0 }, 117 { "december", DEC,0 }, 118 { "sunday", SUN, 0 }, 119 { "sun", SUN, 0 }, 120 { "monday", MON, 0 }, 121 { "mon", MON, 0 }, 122 { "tuesday", TUE, 0 }, 123 { "tue", TUE, 0 }, 124 { "wednesday", WED, 0 }, 125 { "wed", WED, 0 }, 126 { "thursday", THU, 0 }, 127 { "thu", THU, 0 }, 128 { "friday", FRI, 0 }, 129 { "fri", FRI, 0 }, 130 { "saturday", SAT, 0 }, 131 { "sat", SAT, 0 }, 132}; 133 134static char **scp; /* scanner - pointer at arglist */ 135static int scc; /* scanner - count of remaining arguments */ 136static char *sct; /* scanner - next char pointer in current argument */ 137static int need; /* scanner - need to advance to next argument */ 138static char *sc_token; /* scanner - token buffer */ 139static size_t sc_len; /* scanner - length of token buffer */ 140static int sc_tokid; /* scanner - token id */ 141static int sc_tokplur; /* scanner - is token plural? */ 142 143#ifndef lint 144static const char rcsid[] = "$OpenBSD: parsetime.c,v 1.16 2007/05/23 19:50:28 millert Exp $"; 145#endif 146 147/* 148 * parse a token, checking if it's something special to us 149 */ 150static int 151parse_token(char *arg) 152{ 153 int i; 154 155 for (i=0; i < sizeof(Specials) / sizeof(Specials[0]); i++) { 156 if (strcasecmp(Specials[i].name, arg) == 0) { 157 sc_tokplur = Specials[i].plural; 158 return (sc_tokid = Specials[i].value); 159 } 160 } 161 162 /* not special - must be some random id */ 163 return (ID); 164} 165 166 167/* 168 * init_scanner() sets up the scanner to eat arguments 169 */ 170static int 171init_scanner(int argc, char **argv) 172{ 173 scp = argv; 174 scc = argc; 175 need = 1; 176 sc_len = 1; 177 while (argc-- > 0) 178 sc_len += strlen(*argv++); 179 180 if ((sc_token = (char *) malloc(sc_len)) == NULL) { 181 fprintf(stderr, "%s: Insufficient virtual memory\n", 182 ProgramName); 183 return (-1); 184 } 185 return (0); 186} 187 188/* 189 * token() fetches a token from the input stream 190 */ 191static int 192token(void) 193{ 194 int idx; 195 196 for (;;) { 197 bzero(sc_token, sc_len); 198 sc_tokid = EOF; 199 sc_tokplur = 0; 200 idx = 0; 201 202 /* 203 * if we need to read another argument, walk along the 204 * argument list; when we fall off the arglist, we'll 205 * just return EOF forever 206 */ 207 if (need) { 208 if (scc < 1) 209 return (sc_tokid); 210 sct = *scp; 211 scp++; 212 scc--; 213 need = 0; 214 } 215 /* 216 * eat whitespace now - if we walk off the end of the argument, 217 * we'll continue, which puts us up at the top of the while loop 218 * to fetch the next argument in 219 */ 220 while (isspace(*sct)) 221 ++sct; 222 if (!*sct) { 223 need = 1; 224 continue; 225 } 226 227 /* 228 * preserve the first character of the new token 229 */ 230 sc_token[0] = *sct++; 231 232 /* 233 * then see what it is 234 */ 235 if (isdigit(sc_token[0])) { 236 while (isdigit(*sct)) 237 sc_token[++idx] = *sct++; 238 sc_token[++idx] = 0; 239 return ((sc_tokid = NUMBER)); 240 } else if (isalpha(sc_token[0])) { 241 while (isalpha(*sct)) 242 sc_token[++idx] = *sct++; 243 sc_token[++idx] = 0; 244 return (parse_token(sc_token)); 245 } 246 else if (sc_token[0] == ':' || sc_token[0] == '.') 247 return ((sc_tokid = DOT)); 248 else if (sc_token[0] == '+') 249 return ((sc_tokid = PLUS)); 250 else if (sc_token[0] == '/') 251 return ((sc_tokid = SLASH)); 252 else 253 return ((sc_tokid = JUNK)); 254 } 255} 256 257 258/* 259 * plonk() gives an appropriate error message if a token is incorrect 260 */ 261static void 262plonk(int tok) 263{ 264 fprintf(stderr, "%s: %s time\n", ProgramName, 265 (tok == EOF) ? "incomplete" : "garbled"); 266} 267 268 269/* 270 * expect() gets a token and returns -1 if it's not the token we want 271 */ 272static int 273expect(int desired) 274{ 275 if (token() != desired) { 276 plonk(sc_tokid); 277 return (-1); 278 } 279 return (0); 280} 281 282 283/* 284 * dateadd() adds a number of minutes to a date. It is extraordinarily 285 * stupid regarding day-of-month overflow, and will most likely not 286 * work properly 287 */ 288static void 289dateadd(int minutes, struct tm *tm) 290{ 291 /* increment days */ 292 293 while (minutes > 24*60) { 294 minutes -= 24*60; 295 tm->tm_mday++; 296 } 297 298 /* increment hours */ 299 while (minutes > 60) { 300 minutes -= 60; 301 tm->tm_hour++; 302 if (tm->tm_hour > 23) { 303 tm->tm_mday++; 304 tm->tm_hour = 0; 305 } 306 } 307 308 /* increment minutes */ 309 tm->tm_min += minutes; 310 311 if (tm->tm_min > 59) { 312 tm->tm_hour++; 313 tm->tm_min -= 60; 314 315 if (tm->tm_hour > 23) { 316 tm->tm_mday++; 317 tm->tm_hour = 0; 318 } 319 } 320} 321 322 323/* 324 * plus() parses a now + time 325 * 326 * at [NOW] PLUS NUMBER [MINUTES|HOURS|DAYS|WEEKS] 327 * 328 */ 329static int 330plus(struct tm *tm) 331{ 332 int delay; 333 int expectplur; 334 335 if (expect(NUMBER) != 0) 336 return (-1); 337 338 delay = atoi(sc_token); 339 expectplur = (delay != 1) ? 1 : 0; 340 341 switch (token()) { 342 case WEEKS: 343 delay *= 7; 344 /* FALLTHROUGH */ 345 case DAYS: 346 delay *= 24; 347 /* FALLTHROUGH */ 348 case HOURS: 349 delay *= 60; 350 /* FALLTHROUGH */ 351 case MINUTES: 352 if (expectplur != sc_tokplur) 353 fprintf(stderr, "%s: pluralization is wrong\n", 354 ProgramName); 355 dateadd(delay, tm); 356 return (0); 357 } 358 359 plonk(sc_tokid); 360 return (-1); 361} 362 363 364/* 365 * tod() computes the time of day 366 * [NUMBER [DOT NUMBER] [AM|PM]] 367 */ 368static int 369tod(struct tm *tm) 370{ 371 int hour, minute = 0; 372 size_t tlen; 373 374 hour = atoi(sc_token); 375 tlen = strlen(sc_token); 376 377 /* 378 * first pick out the time of day - if it's 4 digits, we assume 379 * a HHMM time, otherwise it's HH DOT MM time 380 */ 381 if (token() == DOT) { 382 if (expect(NUMBER) != 0) 383 return (-1); 384 minute = atoi(sc_token); 385 if (minute > 59) 386 goto bad; 387 token(); 388 } else if (tlen == 4) { 389 minute = hour % 100; 390 if (minute > 59) 391 goto bad; 392 hour = hour / 100; 393 } 394 395 /* 396 * check if an AM or PM specifier was given 397 */ 398 if (sc_tokid == AM || sc_tokid == PM) { 399 if (hour > 12) 400 goto bad; 401 402 if (sc_tokid == PM) { 403 if (hour != 12) /* 12:xx PM is 12:xx, not 24:xx */ 404 hour += 12; 405 } else { 406 if (hour == 12) /* 12:xx AM is 00:xx, not 12:xx */ 407 hour = 0; 408 } 409 token(); 410 } else if (hour > 23) 411 goto bad; 412 413 /* 414 * if we specify an absolute time, we don't want to bump the day even 415 * if we've gone past that time - but if we're specifying a time plus 416 * a relative offset, it's okay to bump things 417 */ 418 if ((sc_tokid == EOF || sc_tokid == PLUS) && tm->tm_hour > hour) { 419 tm->tm_mday++; 420 tm->tm_wday++; 421 } 422 423 tm->tm_hour = hour; 424 tm->tm_min = minute; 425 if (tm->tm_hour == 24) { 426 tm->tm_hour = 0; 427 tm->tm_mday++; 428 } 429 return (0); 430bad: 431 fprintf(stderr, "%s: garbled time\n", ProgramName); 432 return (-1); 433} 434 435 436/* 437 * assign_date() assigns a date, wrapping to next year if needed 438 */ 439static void 440assign_date(struct tm *tm, int mday, int mon, int year) 441{ 442 443 /* 444 * Convert year into tm_year format (year - 1900). 445 * We may be given the year in 2 digit, 4 digit, or tm_year format. 446 */ 447 if (year != -1) { 448 if (year >= TM_YEAR_BASE) 449 year -= TM_YEAR_BASE; /* convert from 4 digit year */ 450 else if (year < 100) { 451 /* Convert to tm_year assuming current century */ 452 year += (tm->tm_year / 100) * 100; 453 454 if (year == tm->tm_year - 1) 455 year++; /* Common off by one error */ 456 else if (year < tm->tm_year) 457 year += 100; /* must be in next century */ 458 } 459 } 460 461 if (year < 0 && 462 (tm->tm_mon > mon ||(tm->tm_mon == mon && tm->tm_mday > mday))) 463 year = tm->tm_year + 1; 464 465 tm->tm_mday = mday; 466 tm->tm_mon = mon; 467 468 if (year >= 0) 469 tm->tm_year = year; 470} 471 472 473/* 474 * month() picks apart a month specification 475 * 476 * /[<month> NUMBER [NUMBER]] \ 477 * |[TOMORROW] | 478 * |[DAY OF WEEK] | 479 * |NUMBER [SLASH NUMBER [SLASH NUMBER]]| 480 * \PLUS NUMBER MINUTES|HOURS|DAYS|WEEKS/ 481 */ 482static int 483month(struct tm *tm) 484{ 485 int year = (-1); 486 int mday, wday, mon; 487 size_t tlen; 488 489 switch (sc_tokid) { 490 case PLUS: 491 if (plus(tm) != 0) 492 return (-1); 493 break; 494 495 case TOMORROW: 496 /* do something tomorrow */ 497 tm->tm_mday++; 498 tm->tm_wday++; 499 case TODAY: 500 /* force ourselves to stay in today - no further processing */ 501 token(); 502 break; 503 504 case JAN: case FEB: case MAR: case APR: case MAY: case JUN: 505 case JUL: case AUG: case SEP: case OCT: case NOV: case DEC: 506 /* 507 * do month mday [year] 508 */ 509 mon = sc_tokid - JAN; 510 if (expect(NUMBER) != 0) 511 return (-1); 512 mday = atoi(sc_token); 513 if (token() == NUMBER) { 514 year = atoi(sc_token); 515 token(); 516 } 517 assign_date(tm, mday, mon, year); 518 break; 519 520 case SUN: case MON: case TUE: 521 case WED: case THU: case FRI: 522 case SAT: 523 /* do a particular day of the week */ 524 wday = sc_tokid - SUN; 525 526 mday = tm->tm_mday; 527 528 /* if this day is < today, then roll to next week */ 529 if (wday < tm->tm_wday) 530 mday += 7 - (tm->tm_wday - wday); 531 else 532 mday += (wday - tm->tm_wday); 533 534 tm->tm_wday = wday; 535 536 assign_date(tm, mday, tm->tm_mon, tm->tm_year); 537 break; 538 539 case NUMBER: 540 /* 541 * get numeric MMDDYY, mm/dd/yy, or dd.mm.yy 542 */ 543 tlen = strlen(sc_token); 544 mon = atoi(sc_token); 545 token(); 546 547 if (sc_tokid == SLASH || sc_tokid == DOT) { 548 int sep; 549 550 sep = sc_tokid; 551 if (expect(NUMBER) != 0) 552 return (-1); 553 mday = atoi(sc_token); 554 if (token() == sep) { 555 if (expect(NUMBER) != 0) 556 return (-1); 557 year = atoi(sc_token); 558 token(); 559 } 560 561 /* 562 * flip months and days for european timing 563 */ 564 if (sep == DOT) { 565 int x = mday; 566 mday = mon; 567 mon = x; 568 } 569 } else if (tlen == 6 || tlen == 8) { 570 if (tlen == 8) { 571 year = (mon % 10000) - TM_YEAR_BASE; 572 mon /= 10000; 573 } else { 574 year = mon % 100; 575 mon /= 100; 576 } 577 mday = mon % 100; 578 mon /= 100; 579 } else 580 goto bad; 581 582 mon--; 583 if (mon < 0 || mon > 11 || mday < 1 || mday > 31) 584 goto bad; 585 586 assign_date(tm, mday, mon, year); 587 break; 588 } 589 return (0); 590bad: 591 fprintf(stderr, "%s: garbled time\n", ProgramName); 592 return (-1); 593} 594 595 596time_t 597parsetime(int argc, char **argv) 598{ 599 /* 600 * Do the argument parsing, die if necessary, and return the 601 * time the job should be run. 602 */ 603 time_t nowtimer, runtimer; 604 struct tm nowtime, runtime; 605 int hr = 0; 606 /* this MUST be initialized to zero for midnight/noon/teatime */ 607 608 if (argc == 0) 609 return (-1); 610 611 nowtimer = time(NULL); 612 nowtime = *localtime(&nowtimer); 613 614 runtime = nowtime; 615 runtime.tm_sec = 0; 616 runtime.tm_isdst = 0; 617 618 if (init_scanner(argc, argv) == -1) 619 return (-1); 620 621 switch (token()) { 622 case NOW: /* now is optional prefix for PLUS tree */ 623 token(); 624 if (sc_tokid == EOF) { 625 runtime = nowtime; 626 break; 627 } 628 else if (sc_tokid != PLUS) 629 plonk(sc_tokid); 630 case PLUS: 631 if (plus(&runtime) != 0) 632 return (-1); 633 break; 634 635 case NUMBER: 636 if (tod(&runtime) != 0 || month(&runtime) != 0) 637 return (-1); 638 break; 639 640 /* 641 * evil coding for TEATIME|NOON|MIDNIGHT - we've initialised 642 * hr to zero up above, then fall into this case in such a 643 * way so we add +12 +4 hours to it for teatime, +12 hours 644 * to it for noon, and nothing at all for midnight, then 645 * set our runtime to that hour before leaping into the 646 * month scanner 647 */ 648 case TEATIME: 649 hr += 4; 650 /* FALLTHROUGH */ 651 case NOON: 652 hr += 12; 653 /* FALLTHROUGH */ 654 case MIDNIGHT: 655 if (runtime.tm_hour >= hr) { 656 runtime.tm_mday++; 657 runtime.tm_wday++; 658 } 659 runtime.tm_hour = hr; 660 runtime.tm_min = 0; 661 token(); 662 /* fall through to month setting */ 663 /* FALLTHROUGH */ 664 default: 665 if (month(&runtime) != 0) 666 return (-1); 667 break; 668 } /* ugly case statement */ 669 if (expect(EOF) != 0) 670 return (-1); 671 672 /* 673 * adjust for daylight savings time 674 */ 675 runtime.tm_isdst = -1; 676 runtimer = mktime(&runtime); 677 if (runtime.tm_isdst > 0) { 678 runtimer -= 3600; 679 runtimer = mktime(&runtime); 680 } 681 682 if (runtimer < 0) { 683 fprintf(stderr, "%s: garbled time\n", ProgramName); 684 return (-1); 685 } 686 687 if (nowtimer > runtimer) { 688 fprintf(stderr, "%s: cannot schedule jobs in the past\n", 689 ProgramName); 690 return (-1); 691 } 692 693 return (runtimer); 694} 695