1 /* $OpenBSD: parsetime.c,v 1.9 2000/01/05 08:06:25 millert Exp $ */ 2 /* $NetBSD: parsetime.c,v 1.3 1995/03/25 18:13:36 glass Exp $ */ 3 4 /* 5 * parsetime.c - parse time for at(1) 6 * Copyright (C) 1993, 1994 Thomas Koenig 7 * 8 * modifications for english-language times 9 * Copyright (C) 1993 David Parsons 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. The name of the author(s) may not be used to endorse or promote 17 * products derived from this software without specific prior written 18 * permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR 21 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 22 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 23 * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT, 24 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 25 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 * THEORY OF LIABILITY, WETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 29 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 * 31 * at [NOW] PLUS NUMBER MINUTES|HOURS|DAYS|WEEKS 32 * /NUMBER [DOT NUMBER] [AM|PM]\ /[MONTH NUMBER [NUMBER]] \ 33 * |NOON | |[TOMORROW] | 34 * |MIDNIGHT | |[DAY OF WEEK] | 35 * \TEATIME / |NUMBER [SLASH NUMBER [SLASH NUMBER]]| 36 * \PLUS NUMBER MINUTES|HOURS|DAYS|WEEKS/ 37 */ 38 39 /* System Headers */ 40 41 #include <sys/types.h> 42 #include <errno.h> 43 #include <stdio.h> 44 #include <stdlib.h> 45 #include <string.h> 46 #include <time.h> 47 #include <tzfile.h> 48 #include <unistd.h> 49 #include <ctype.h> 50 #include <err.h> 51 52 /* Local headers */ 53 54 #include "at.h" 55 #include "panic.h" 56 57 58 /* Structures and unions */ 59 60 enum { /* symbols */ 61 MIDNIGHT, NOON, TEATIME, 62 PM, AM, TOMORROW, TODAY, NOW, 63 MINUTES, HOURS, DAYS, WEEKS, 64 NUMBER, PLUS, DOT, SLASH, ID, JUNK, 65 JAN, FEB, MAR, APR, MAY, JUN, 66 JUL, AUG, SEP, OCT, NOV, DEC, 67 SUN, MON, TUE, WED, THU, FRI, SAT 68 }; 69 70 /* 71 * parse translation table - table driven parsers can be your FRIEND! 72 */ 73 struct { 74 char *name; /* token name */ 75 int value; /* token id */ 76 int plural; /* is this plural? */ 77 } Specials[] = { 78 { "midnight", MIDNIGHT, 0 }, /* 00:00:00 of today or tomorrow */ 79 { "noon", NOON, 0 }, /* 12:00:00 of today or tomorrow */ 80 { "teatime", TEATIME, 0 }, /* 16:00:00 of today or tomorrow */ 81 { "am", AM, 0 }, /* morning times for 0-12 clock */ 82 { "pm", PM, 0 }, /* evening times for 0-12 clock */ 83 { "tomorrow", TOMORROW, 0 }, /* execute 24 hours from time */ 84 { "today", TODAY, 0 }, /* execute today - don't advance time */ 85 { "now", NOW, 0 }, /* opt prefix for PLUS */ 86 87 { "minute", MINUTES, 0 }, /* minutes multiplier */ 88 { "min", MINUTES, 0 }, 89 { "m", MINUTES, 0 }, 90 { "minutes", MINUTES, 1 }, /* (pluralized) */ 91 { "hour", HOURS, 0 }, /* hours ... */ 92 { "hr", HOURS, 0 }, /* abbreviated */ 93 { "h", HOURS, 0 }, 94 { "hours", HOURS, 1 }, /* (pluralized) */ 95 { "day", DAYS, 0 }, /* days ... */ 96 { "d", DAYS, 0 }, 97 { "days", DAYS, 1 }, /* (pluralized) */ 98 { "week", WEEKS, 0 }, /* week ... */ 99 { "w", WEEKS, 0 }, 100 { "weeks", WEEKS, 1 }, /* (pluralized) */ 101 { "jan", JAN, 0 }, 102 { "feb", FEB, 0 }, 103 { "mar", MAR, 0 }, 104 { "apr", APR, 0 }, 105 { "may", MAY, 0 }, 106 { "jun", JUN, 0 }, 107 { "jul", JUL, 0 }, 108 { "aug", AUG, 0 }, 109 { "sep", SEP, 0 }, 110 { "oct", OCT, 0 }, 111 { "nov", NOV, 0 }, 112 { "dec", DEC, 0 }, 113 { "january", JAN,0 }, 114 { "february", FEB,0 }, 115 { "march", MAR,0 }, 116 { "april", APR,0 }, 117 { "may", MAY,0 }, 118 { "june", JUN,0 }, 119 { "july", JUL,0 }, 120 { "august", AUG,0 }, 121 { "september", SEP,0 }, 122 { "october", OCT,0 }, 123 { "november", NOV,0 }, 124 { "december", DEC,0 }, 125 { "sunday", SUN, 0 }, 126 { "sun", SUN, 0 }, 127 { "monday", MON, 0 }, 128 { "mon", MON, 0 }, 129 { "tuesday", TUE, 0 }, 130 { "tue", TUE, 0 }, 131 { "wednesday", WED, 0 }, 132 { "wed", WED, 0 }, 133 { "thursday", THU, 0 }, 134 { "thu", THU, 0 }, 135 { "friday", FRI, 0 }, 136 { "fri", FRI, 0 }, 137 { "saturday", SAT, 0 }, 138 { "sat", SAT, 0 }, 139 }; 140 141 /* File scope variables */ 142 143 static char **scp; /* scanner - pointer at arglist */ 144 static char 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 */ 147 148 static char *sc_token; /* scanner - token buffer */ 149 static size_t sc_len; /* scanner - lenght of token buffer */ 150 static int sc_tokid; /* scanner - token id */ 151 static int sc_tokplur; /* scanner - is token plural? */ 152 153 #ifndef lint 154 static char rcsid[] = "$OpenBSD: parsetime.c,v 1.9 2000/01/05 08:06:25 millert Exp $"; 155 #endif 156 157 /* Local functions */ 158 159 /* 160 * parse a token, checking if it's something special to us 161 */ 162 static int 163 parse_token(arg) 164 char *arg; 165 { 166 int i; 167 168 for (i=0; i < sizeof(Specials) / sizeof(Specials[0]); i++) { 169 if (strcasecmp(Specials[i].name, arg) == 0) { 170 sc_tokplur = Specials[i].plural; 171 return (sc_tokid = Specials[i].value); 172 } 173 } 174 175 /* not special - must be some random id */ 176 return (ID); 177 } /* parse_token */ 178 179 180 /* 181 * init_scanner() sets up the scanner to eat arguments 182 */ 183 static void 184 init_scanner(argc, argv) 185 int argc; 186 char **argv; 187 { 188 scp = argv; 189 scc = argc; 190 need = 1; 191 sc_len = 1; 192 while (argc-- > 0) 193 sc_len += strlen(*argv++); 194 195 if ((sc_token = (char *) malloc(sc_len)) == NULL) 196 panic("Insufficient virtual memory"); 197 } /* init_scanner */ 198 199 /* 200 * token() fetches a token from the input stream 201 */ 202 static int 203 token() 204 { 205 int idx; 206 207 while (1) { 208 (void)memset(sc_token, 0, sc_len); 209 sc_tokid = EOF; 210 sc_tokplur = 0; 211 idx = 0; 212 213 /* 214 * if we need to read another argument, walk along the 215 * argument list; when we fall off the arglist, we'll 216 * just return EOF forever 217 */ 218 if (need) { 219 if (scc < 1) 220 return (sc_tokid); 221 sct = *scp; 222 scp++; 223 scc--; 224 need = 0; 225 } 226 /* 227 * eat whitespace now - if we walk off the end of the argument, 228 * we'll continue, which puts us up at the top of the while loop 229 * to fetch the next argument in 230 */ 231 while (isspace(*sct)) 232 ++sct; 233 if (!*sct) { 234 need = 1; 235 continue; 236 } 237 238 /* 239 * preserve the first character of the new token 240 */ 241 sc_token[0] = *sct++; 242 243 /* 244 * then see what it is 245 */ 246 if (isdigit(sc_token[0])) { 247 while (isdigit(*sct)) 248 sc_token[++idx] = *sct++; 249 sc_token[++idx] = 0; 250 return ((sc_tokid = NUMBER)); 251 } else if (isalpha(sc_token[0])) { 252 while (isalpha(*sct)) 253 sc_token[++idx] = *sct++; 254 sc_token[++idx] = 0; 255 return (parse_token(sc_token)); 256 } 257 else if (sc_token[0] == ':' || sc_token[0] == '.') 258 return ((sc_tokid = DOT)); 259 else if (sc_token[0] == '+') 260 return ((sc_tokid = PLUS)); 261 else if (sc_token[0] == '/') 262 return ((sc_tokid = SLASH)); 263 else 264 return ((sc_tokid = JUNK)); 265 } /* while (1) */ 266 } /* token */ 267 268 269 /* 270 * plonk() gives an appropriate error message if a token is incorrect 271 */ 272 static void 273 plonk(tok) 274 int tok; 275 { 276 panic((tok == EOF) ? "incomplete time" : "garbled time"); 277 } /* plonk */ 278 279 280 /* 281 * expect() gets a token and dies most horribly if it's not the token we want 282 */ 283 static void 284 expect(desired) 285 int desired; 286 { 287 if (token() != desired) 288 plonk(sc_tokid); /* and we die here... */ 289 } /* expect */ 290 291 292 /* 293 * dateadd() adds a number of minutes to a date. It is extraordinarily 294 * stupid regarding day-of-month overflow, and will most likely not 295 * work properly 296 */ 297 static void 298 dateadd(minutes, tm) 299 int minutes; 300 struct tm *tm; 301 { 302 /* increment days */ 303 304 while (minutes > 24*60) { 305 minutes -= 24*60; 306 tm->tm_mday++; 307 } 308 309 /* increment hours */ 310 while (minutes > 60) { 311 minutes -= 60; 312 tm->tm_hour++; 313 if (tm->tm_hour > 23) { 314 tm->tm_mday++; 315 tm->tm_hour = 0; 316 } 317 } 318 319 /* increment minutes */ 320 tm->tm_min += minutes; 321 322 if (tm->tm_min > 59) { 323 tm->tm_hour++; 324 tm->tm_min -= 60; 325 326 if (tm->tm_hour > 23) { 327 tm->tm_mday++; 328 tm->tm_hour = 0; 329 } 330 } 331 } /* dateadd */ 332 333 334 /* 335 * plus() parses a now + time 336 * 337 * at [NOW] PLUS NUMBER [MINUTES|HOURS|DAYS|WEEKS] 338 * 339 */ 340 static void 341 plus(tm) 342 struct tm *tm; 343 { 344 int delay; 345 int expectplur; 346 347 expect(NUMBER); 348 349 delay = atoi(sc_token); 350 expectplur = (delay != 1) ? 1 : 0; 351 352 switch (token()) { 353 case WEEKS: 354 delay *= 7; 355 case DAYS: 356 delay *= 24; 357 case HOURS: 358 delay *= 60; 359 case MINUTES: 360 if (expectplur != sc_tokplur) 361 warnx("pluralization is wrong"); 362 dateadd(delay, tm); 363 return; 364 } 365 366 plonk(sc_tokid); 367 } /* plus */ 368 369 370 /* 371 * tod() computes the time of day 372 * [NUMBER [DOT NUMBER] [AM|PM]] 373 */ 374 static void 375 tod(tm) 376 struct tm *tm; 377 { 378 int hour, minute = 0; 379 size_t tlen; 380 381 hour = atoi(sc_token); 382 tlen = strlen(sc_token); 383 384 /* 385 * first pick out the time of day - if it's 4 digits, we assume 386 * a HHMM time, otherwise it's HH DOT MM time 387 */ 388 if (token() == DOT) { 389 expect(NUMBER); 390 minute = atoi(sc_token); 391 if (minute > 59) 392 panic("garbled time"); 393 token(); 394 } else if (tlen == 4) { 395 minute = hour % 100; 396 if (minute > 59) 397 panic("garbled time"); 398 hour = hour / 100; 399 } 400 401 /* 402 * check if an AM or PM specifier was given 403 */ 404 if (sc_tokid == AM || sc_tokid == PM) { 405 if (hour > 12) 406 panic("garbled time"); 407 408 if (sc_tokid == PM) { 409 if (hour != 12) /* 12:xx PM is 12:xx, not 24:xx */ 410 hour += 12; 411 } else { 412 if (hour == 12) /* 12:xx AM is 00:xx, not 12:xx */ 413 hour = 0; 414 } 415 token(); 416 } else if (hour > 23) 417 panic("garbled time"); 418 419 /* 420 * if we specify an absolute time, we don't want to bump the day even 421 * if we've gone past that time - but if we're specifying a time plus 422 * a relative offset, it's okay to bump things 423 */ 424 if ((sc_tokid == EOF || sc_tokid == PLUS) && tm->tm_hour > hour) { 425 tm->tm_mday++; 426 tm->tm_wday++; 427 } 428 429 tm->tm_hour = hour; 430 tm->tm_min = minute; 431 if (tm->tm_hour == 24) { 432 tm->tm_hour = 0; 433 tm->tm_mday++; 434 } 435 } /* tod */ 436 437 438 /* 439 * assign_date() assigns a date, wrapping to next year if needed 440 */ 441 static void 442 assign_date(tm, mday, mon, year) 443 struct tm *tm; 444 int mday, mon, year; 445 { 446 447 /* 448 * Convert year into tm_year format (year - 1900). 449 * We may be given the year in 2 digit, 4 digit, or tm_year format. 450 */ 451 if (year != -1) { 452 if (year >= TM_YEAR_BASE) 453 year -= TM_YEAR_BASE; /* convert from 4 digit year */ 454 else if (year < 100) { 455 /* Convert to tm_year assuming current century */ 456 year += (tm->tm_year / 100) * 100; 457 458 if (year == tm->tm_year - 1) 459 year++; /* Common off by one error */ 460 else if (year < tm->tm_year) 461 year += 100; /* must be in next century */ 462 } 463 } 464 465 if (year < 0 && 466 (tm->tm_mon > mon ||(tm->tm_mon == mon && tm->tm_mday > mday))) 467 year = tm->tm_year + 1; 468 469 tm->tm_mday = mday; 470 tm->tm_mon = mon; 471 472 if (year >= 0) 473 tm->tm_year = year; 474 } /* assign_date */ 475 476 477 /* 478 * month() picks apart a month specification 479 * 480 * /[<month> NUMBER [NUMBER]] \ 481 * |[TOMORROW] | 482 * |[DAY OF WEEK] | 483 * |NUMBER [SLASH NUMBER [SLASH NUMBER]]| 484 * \PLUS NUMBER MINUTES|HOURS|DAYS|WEEKS/ 485 */ 486 static void 487 month(tm) 488 struct tm *tm; 489 { 490 int year = (-1); 491 int mday, wday, mon; 492 size_t tlen; 493 494 switch (sc_tokid) { 495 case PLUS: 496 plus(tm); 497 break; 498 499 case TOMORROW: 500 /* do something tomorrow */ 501 tm->tm_mday++; 502 tm->tm_wday++; 503 case TODAY: 504 /* force ourselves to stay in today - no further processing */ 505 token(); 506 break; 507 508 case JAN: case FEB: case MAR: case APR: case MAY: case JUN: 509 case JUL: case AUG: case SEP: case OCT: case NOV: case DEC: 510 /* 511 * do month mday [year] 512 */ 513 mon = sc_tokid - JAN; 514 expect(NUMBER); 515 mday = atoi(sc_token); 516 if (token() == NUMBER) { 517 year = atoi(sc_token); 518 token(); 519 } 520 assign_date(tm, mday, mon, year); 521 break; 522 523 case SUN: case MON: case TUE: 524 case WED: case THU: case FRI: 525 case SAT: 526 /* do a particular day of the week */ 527 wday = sc_tokid - SUN; 528 529 mday = tm->tm_mday; 530 531 /* if this day is < today, then roll to next week */ 532 if (wday < tm->tm_wday) 533 mday += 7 - (tm->tm_wday - wday); 534 else 535 mday += (wday - tm->tm_wday); 536 537 tm->tm_wday = wday; 538 539 assign_date(tm, mday, tm->tm_mon, tm->tm_year); 540 break; 541 542 case NUMBER: 543 /* 544 * get numeric MMDDYY, mm/dd/yy, or dd.mm.yy 545 */ 546 tlen = strlen(sc_token); 547 mon = atoi(sc_token); 548 token(); 549 550 if (sc_tokid == SLASH || sc_tokid == DOT) { 551 int sep; 552 553 sep = sc_tokid; 554 expect(NUMBER); 555 mday = atoi(sc_token); 556 if (token() == sep) { 557 expect(NUMBER); 558 year = atoi(sc_token); 559 token(); 560 } 561 562 /* 563 * flip months and days for european timing 564 */ 565 if (sep == DOT) { 566 int x = mday; 567 mday = mon; 568 mon = x; 569 } 570 } else if (tlen == 6 || tlen == 8) { 571 if (tlen == 8) { 572 year = (mon % 10000) - TM_YEAR_BASE; 573 mon /= 10000; 574 } else { 575 year = mon % 100; 576 mon /= 100; 577 } 578 mday = mon % 100; 579 mon /= 100; 580 } else 581 panic("garbled time"); 582 583 mon--; 584 if (mon < 0 || mon > 11 || mday < 1 || mday > 31) 585 panic("garbled time"); 586 587 assign_date(tm, mday, mon, year); 588 break; 589 } /* case */ 590 } /* month */ 591 592 593 /* Global functions */ 594 595 time_t 596 parsetime(argc, argv) 597 int argc; 598 char **argv; 599 { 600 /* 601 * Do the argument parsing, die if necessary, and return the 602 * time the job should be run. 603 */ 604 time_t nowtimer, runtimer; 605 struct tm nowtime, runtime; 606 int hr = 0; 607 /* this MUST be initialized to zero for midnight/noon/teatime */ 608 609 nowtimer = time(NULL); 610 nowtime = *localtime(&nowtimer); 611 612 runtime = nowtime; 613 runtime.tm_sec = 0; 614 runtime.tm_isdst = 0; 615 616 if (argc <= optind) 617 usage(); 618 619 init_scanner(argc - optind, argv + optind); 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 plus(&runtime); 632 break; 633 634 case NUMBER: 635 tod(&runtime); 636 month(&runtime); 637 break; 638 639 /* 640 * evil coding for TEATIME|NOON|MIDNIGHT - we've initialised 641 * hr to zero up above, then fall into this case in such a 642 * way so we add +12 +4 hours to it for teatime, +12 hours 643 * to it for noon, and nothing at all for midnight, then 644 * set our runtime to that hour before leaping into the 645 * month scanner 646 */ 647 case TEATIME: 648 hr += 4; 649 case NOON: 650 hr += 12; 651 case MIDNIGHT: 652 if (runtime.tm_hour >= hr) { 653 runtime.tm_mday++; 654 runtime.tm_wday++; 655 } 656 runtime.tm_hour = hr; 657 runtime.tm_min = 0; 658 token(); 659 /* fall through to month setting */ 660 default: 661 month(&runtime); 662 break; 663 } /* ugly case statement */ 664 expect(EOF); 665 666 /* 667 * adjust for daylight savings time 668 */ 669 runtime.tm_isdst = -1; 670 runtimer = mktime(&runtime); 671 if (runtime.tm_isdst > 0) { 672 runtimer -= 3600; 673 runtimer = mktime(&runtime); 674 } 675 676 if (runtimer < 0) 677 panic("garbled time"); 678 679 if (nowtimer > runtimer) 680 panic("Trying to travel back in time"); 681 682 return (runtimer); 683 } /* parsetime */ 684