parsetime.c revision 87230
1/* 2 * parsetime.c - parse time for at(1) 3 * Copyright (C) 1993, 1994 Thomas Koenig 4 * 5 * modifications for English-language times 6 * Copyright (C) 1993 David Parsons 7 * 8 * Redistribution and use in source and binary forms, with or without 9 * modification, are permitted provided that the following conditions 10 * are met: 11 * 1. Redistributions of source code must retain the above copyright 12 * notice, this list of conditions and the following disclaimer. 13 * 2. The name of the author(s) may not be used to endorse or promote 14 * products derived from this software without specific prior written 15 * permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR 18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 20 * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT, 21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24 * THEORY OF LIABILITY, WETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 * 28 * at [NOW] PLUS NUMBER MINUTES|HOURS|DAYS|WEEKS 29 * /NUMBER [DOT NUMBER] [AM|PM]\ /[MONTH NUMBER [NUMBER]] \ 30 * |NOON | |[TOMORROW] | 31 * |MIDNIGHT | |[DAY OF WEEK] | 32 * \TEATIME / |NUMBER [SLASH NUMBER [SLASH NUMBER]]| 33 * \PLUS NUMBER MINUTES|HOURS|DAYS|WEEKS/ 34 */ 35 36#include <sys/cdefs.h> 37 38__FBSDID("$FreeBSD: head/usr.bin/at/parsetime.c 87230 2001-12-02 20:23:02Z markm $"); 39 40/* System Headers */ 41 42#include <sys/types.h> 43#include <ctype.h> 44#include <err.h> 45#include <errno.h> 46#include <stdio.h> 47#include <stdlib.h> 48#include <string.h> 49#include <time.h> 50#include <unistd.h> 51#ifndef __FreeBSD__ 52#include <getopt.h> 53#endif 54 55/* Local headers */ 56 57#include "at.h" 58#include "panic.h" 59#include "parsetime.h" 60 61 62/* Structures and unions */ 63 64enum { /* symbols */ 65 MIDNIGHT, NOON, TEATIME, 66 PM, AM, TOMORROW, TODAY, NOW, 67 MINUTES, HOURS, DAYS, WEEKS, MONTHS, YEARS, 68 NUMBER, PLUS, DOT, SLASH, ID, JUNK, 69 JAN, FEB, MAR, APR, MAY, JUN, 70 JUL, AUG, SEP, OCT, NOV, DEC, 71 SUN, MON, TUE, WED, THU, FRI, SAT 72 }; 73 74/* parse translation table - table driven parsers can be your FRIEND! 75 */ 76struct { 77 const char *name; /* token name */ 78 int value; /* token id */ 79 int plural; /* is this plural? */ 80} Specials[] = { 81 { "midnight", MIDNIGHT,0 }, /* 00:00:00 of today or tomorrow */ 82 { "noon", NOON,0 }, /* 12:00:00 of today or tomorrow */ 83 { "teatime", TEATIME,0 }, /* 16:00:00 of today or tomorrow */ 84 { "am", AM,0 }, /* morning times for 0-12 clock */ 85 { "pm", PM,0 }, /* evening times for 0-12 clock */ 86 { "tomorrow", TOMORROW,0 }, /* execute 24 hours from time */ 87 { "today", TODAY, 0 }, /* execute today - don't advance time */ 88 { "now", NOW,0 }, /* opt prefix for PLUS */ 89 90 { "minute", MINUTES,0 }, /* minutes multiplier */ 91 { "minutes", MINUTES,1 }, /* (pluralized) */ 92 { "hour", HOURS,0 }, /* hours ... */ 93 { "hours", HOURS,1 }, /* (pluralized) */ 94 { "day", DAYS,0 }, /* days ... */ 95 { "days", DAYS,1 }, /* (pluralized) */ 96 { "week", WEEKS,0 }, /* week ... */ 97 { "weeks", WEEKS,1 }, /* (pluralized) */ 98 { "month", MONTHS,0 }, /* month ... */ 99 { "months", MONTHS,1 }, /* (pluralized) */ 100 { "year", YEARS,0 }, /* year ... */ 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/* File scope variables */ 143 144static char **scp; /* scanner - pointer at arglist */ 145static char scc; /* scanner - count of remaining arguments */ 146static char *sct; /* scanner - next char pointer in current argument */ 147static int need; /* scanner - need to advance to next argument */ 148 149static char *sc_token; /* scanner - token buffer */ 150static size_t sc_len; /* scanner - length of token buffer */ 151static int sc_tokid; /* scanner - token id */ 152static int sc_tokplur; /* scanner - is token plural? */ 153 154/* Local functions */ 155 156/* 157 * parse a token, checking if it's something special to us 158 */ 159static int 160parse_token(char *arg) 161{ 162 size_t i; 163 164 for (i=0; i<(sizeof Specials/sizeof Specials[0]); i++) 165 if (strcasecmp(Specials[i].name, arg) == 0) { 166 sc_tokplur = Specials[i].plural; 167 return sc_tokid = Specials[i].value; 168 } 169 170 /* not special - must be some random id */ 171 return ID; 172} /* parse_token */ 173 174 175/* 176 * init_scanner() sets up the scanner to eat arguments 177 */ 178static void 179init_scanner(int argc, char **argv) 180{ 181 scp = argv; 182 scc = argc; 183 need = 1; 184 sc_len = 1; 185 while (argc-- > 0) 186 sc_len += strlen(*argv++); 187 188 if ((sc_token = malloc(sc_len)) == NULL) 189 errx(EXIT_FAILURE, "virtual memory exhausted"); 190} /* init_scanner */ 191 192/* 193 * token() fetches a token from the input stream 194 */ 195static int 196token(void) 197{ 198 int idx; 199 200 while (1) { 201 memset(sc_token, 0, sc_len); 202 sc_tokid = EOF; 203 sc_tokplur = 0; 204 idx = 0; 205 206 /* if we need to read another argument, walk along the argument list; 207 * when we fall off the arglist, we'll just return EOF forever 208 */ 209 if (need) { 210 if (scc < 1) 211 return sc_tokid; 212 sct = *scp; 213 scp++; 214 scc--; 215 need = 0; 216 } 217 /* eat whitespace now - if we walk off the end of the argument, 218 * we'll continue, which puts us up at the top of the while loop 219 * to fetch the next argument in 220 */ 221 while (isspace(*sct)) 222 ++sct; 223 if (!*sct) { 224 need = 1; 225 continue; 226 } 227 228 /* preserve the first character of the new token 229 */ 230 sc_token[0] = *sct++; 231 232 /* then see what it is 233 */ 234 if (isdigit(sc_token[0])) { 235 while (isdigit(*sct)) 236 sc_token[++idx] = *sct++; 237 sc_token[++idx] = 0; 238 return sc_tokid = NUMBER; 239 } 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 } /* while (1) */ 255} /* token */ 256 257 258/* 259 * plonk() gives an appropriate error message if a token is incorrect 260 */ 261static void 262plonk(int tok) 263{ 264 panic((tok == EOF) ? "incomplete time" 265 : "garbled time"); 266} /* plonk */ 267 268 269/* 270 * expect() gets a token and dies most horribly if it's not the token we want 271 */ 272static void 273expect(int desired) 274{ 275 if (token() != desired) 276 plonk(sc_tokid); /* and we die here... */ 277} /* expect */ 278 279 280/* 281 * plus() parses a now + time 282 * 283 * at [NOW] PLUS NUMBER [MINUTES|HOURS|DAYS|WEEKS|MONTHS|YEARS] 284 * 285 */ 286 287static void 288plus(struct tm *tm) 289{ 290 int delay; 291 int expectplur; 292 293 expect(NUMBER); 294 295 delay = atoi(sc_token); 296 expectplur = (delay != 1) ? 1 : 0; 297 298 switch (token()) { 299 case YEARS: 300 tm->tm_year += delay; 301 break; 302 case MONTHS: 303 tm->tm_mon += delay; 304 break; 305 case WEEKS: 306 delay *= 7; 307 case DAYS: 308 tm->tm_mday += delay; 309 break; 310 case HOURS: 311 tm->tm_hour += delay; 312 break; 313 case MINUTES: 314 tm->tm_min += delay; 315 break; 316 default: 317 plonk(sc_tokid); 318 break; 319 } 320 321 if (expectplur != sc_tokplur) 322 warnx("pluralization is wrong"); 323 324 tm->tm_isdst = -1; 325 if (mktime(tm) < 0) 326 plonk(sc_tokid); 327 328} /* plus */ 329 330 331/* 332 * tod() computes the time of day 333 * [NUMBER [DOT NUMBER] [AM|PM]] 334 */ 335static void 336tod(struct tm *tm) 337{ 338 int hour, minute = 0; 339 int tlen; 340 341 hour = atoi(sc_token); 342 tlen = strlen(sc_token); 343 344 /* first pick out the time of day - if it's 4 digits, we assume 345 * a HHMM time, otherwise it's HH DOT MM time 346 */ 347 if (token() == DOT) { 348 expect(NUMBER); 349 minute = atoi(sc_token); 350 if (minute > 59) 351 panic("garbled time"); 352 token(); 353 } 354 else if (tlen == 4) { 355 minute = hour%100; 356 if (minute > 59) 357 panic("garbled time"); 358 hour = hour/100; 359 } 360 361 /* check if an AM or PM specifier was given 362 */ 363 if (sc_tokid == AM || sc_tokid == PM) { 364 if (hour > 12) 365 panic("garbled time"); 366 367 if (sc_tokid == PM) { 368 if (hour != 12) /* 12:xx PM is 12:xx, not 24:xx */ 369 hour += 12; 370 } else { 371 if (hour == 12) /* 12:xx AM is 00:xx, not 12:xx */ 372 hour = 0; 373 } 374 token(); 375 } 376 else if (hour > 23) 377 panic("garbled time"); 378 379 /* if we specify an absolute time, we don't want to bump the day even 380 * if we've gone past that time - but if we're specifying a time plus 381 * a relative offset, it's okay to bump things 382 */ 383 if ((sc_tokid == EOF || sc_tokid == PLUS) && tm->tm_hour > hour) { 384 tm->tm_mday++; 385 tm->tm_wday++; 386 } 387 388 tm->tm_hour = hour; 389 tm->tm_min = minute; 390 if (tm->tm_hour == 24) { 391 tm->tm_hour = 0; 392 tm->tm_mday++; 393 } 394} /* tod */ 395 396 397/* 398 * assign_date() assigns a date, wrapping to next year if needed 399 */ 400static void 401assign_date(struct tm *tm, long mday, long mon, long year) 402{ 403 404 /* 405 * Convert year into tm_year format (year - 1900). 406 * We may be given the year in 2 digit, 4 digit, or tm_year format. 407 */ 408 if (year != -1) { 409 if (year >= 1900) 410 year -= 1900; /* convert from 4 digit year */ 411 else if (year < 100) { 412 /* convert from 2 digit year */ 413 struct tm *lt; 414 time_t now; 415 416 time(&now); 417 lt = localtime(&now); 418 419 /* Convert to tm_year assuming current century */ 420 year += (lt->tm_year / 100) * 100; 421 422 if (year == lt->tm_year - 1) year++; 423 else if (year < lt->tm_year) 424 year += 100; /* must be in next century */ 425 } 426 } 427 428 if (year < 0 && 429 (tm->tm_mon > mon ||(tm->tm_mon == mon && tm->tm_mday > mday))) 430 year = tm->tm_year + 1; 431 432 tm->tm_mday = mday; 433 tm->tm_mon = mon; 434 435 if (year >= 0) 436 tm->tm_year = year; 437} /* assign_date */ 438 439 440/* 441 * month() picks apart a month specification 442 * 443 * /[<month> NUMBER [NUMBER]] \ 444 * |[TOMORROW] | 445 * |[DAY OF WEEK] | 446 * |NUMBER [SLASH NUMBER [SLASH NUMBER]]| 447 * \PLUS NUMBER MINUTES|HOURS|DAYS|WEEKS/ 448 */ 449static void 450month(struct tm *tm) 451{ 452 long year= (-1); 453 long mday = 0, wday, mon; 454 int tlen; 455 456 switch (sc_tokid) { 457 case PLUS: 458 plus(tm); 459 break; 460 461 case TOMORROW: 462 /* do something tomorrow */ 463 tm->tm_mday ++; 464 tm->tm_wday ++; 465 case TODAY: /* force ourselves to stay in today - no further processing */ 466 token(); 467 break; 468 469 case JAN: case FEB: case MAR: case APR: case MAY: case JUN: 470 case JUL: case AUG: case SEP: case OCT: case NOV: case DEC: 471 /* do month mday [year] 472 */ 473 mon = (sc_tokid-JAN); 474 expect(NUMBER); 475 mday = atol(sc_token); 476 if (token() == NUMBER) { 477 year = atol(sc_token); 478 token(); 479 } 480 assign_date(tm, mday, mon, year); 481 break; 482 483 case SUN: case MON: case TUE: 484 case WED: case THU: case FRI: 485 case SAT: 486 /* do a particular day of the week 487 */ 488 wday = (sc_tokid-SUN); 489 490 mday = tm->tm_mday; 491 492 /* if this day is < today, then roll to next week 493 */ 494 if (wday < tm->tm_wday) 495 mday += 7 - (tm->tm_wday - wday); 496 else 497 mday += (wday - tm->tm_wday); 498 499 tm->tm_wday = wday; 500 501 assign_date(tm, mday, tm->tm_mon, tm->tm_year); 502 break; 503 504 case NUMBER: 505 /* get numeric MMDDYY, mm/dd/yy, or dd.mm.yy 506 */ 507 tlen = strlen(sc_token); 508 mon = atol(sc_token); 509 token(); 510 511 if (sc_tokid == SLASH || sc_tokid == DOT) { 512 int sep; 513 514 sep = sc_tokid; 515 expect(NUMBER); 516 mday = atol(sc_token); 517 if (token() == sep) { 518 expect(NUMBER); 519 year = atol(sc_token); 520 token(); 521 } 522 523 /* flip months and days for European timing 524 */ 525 if (sep == DOT) { 526 int x = mday; 527 mday = mon; 528 mon = x; 529 } 530 } 531 else if (tlen == 6 || tlen == 8) { 532 if (tlen == 8) { 533 year = (mon % 10000) - 1900; 534 mon /= 10000; 535 } 536 else { 537 year = mon % 100; 538 mon /= 100; 539 } 540 mday = mon % 100; 541 mon /= 100; 542 } 543 else 544 panic("garbled time"); 545 546 mon--; 547 if (mon < 0 || mon > 11 || mday < 1 || mday > 31) 548 panic("garbled time"); 549 550 assign_date(tm, mday, mon, year); 551 break; 552 } /* case */ 553} /* month */ 554 555 556/* Global functions */ 557 558time_t 559parsetime(int argc, char **argv) 560{ 561/* Do the argument parsing, die if necessary, and return the time the job 562 * should be run. 563 */ 564 time_t nowtimer, runtimer; 565 struct tm nowtime, runtime; 566 int hr = 0; 567 /* this MUST be initialized to zero for midnight/noon/teatime */ 568 569 nowtimer = time(NULL); 570 nowtime = *localtime(&nowtimer); 571 572 runtime = nowtime; 573 runtime.tm_sec = 0; 574 runtime.tm_isdst = 0; 575 576 if (argc <= optind) 577 usage(); 578 579 init_scanner(argc-optind, argv+optind); 580 581 switch (token()) { 582 case NOW: 583 if (scc < 1) { 584 return nowtimer; 585 } 586 /* now is optional prefix for PLUS tree */ 587 expect(PLUS); 588 case PLUS: 589 plus(&runtime); 590 break; 591 592 case NUMBER: 593 tod(&runtime); 594 month(&runtime); 595 break; 596 597 /* evil coding for TEATIME|NOON|MIDNIGHT - we've initialised 598 * hr to zero up above, then fall into this case in such a 599 * way so we add +12 +4 hours to it for teatime, +12 hours 600 * to it for noon, and nothing at all for midnight, then 601 * set our runtime to that hour before leaping into the 602 * month scanner 603 */ 604 case TEATIME: 605 hr += 4; 606 case NOON: 607 hr += 12; 608 case MIDNIGHT: 609 if (runtime.tm_hour >= hr) { 610 runtime.tm_mday++; 611 runtime.tm_wday++; 612 } 613 runtime.tm_hour = hr; 614 runtime.tm_min = 0; 615 token(); 616 /* FALLTHROUGH to month setting */ 617 default: 618 month(&runtime); 619 break; 620 } /* ugly case statement */ 621 expect(EOF); 622 623 /* adjust for daylight savings time 624 */ 625 runtime.tm_isdst = -1; 626 runtimer = mktime(&runtime); 627 if (runtime.tm_isdst > 0) { 628 runtimer -= 3600; 629 runtimer = mktime(&runtime); 630 } 631 632 if (runtimer < 0) 633 panic("garbled time"); 634 635 if (nowtimer > runtimer) 636 panic("trying to travel back in time"); 637 638 return runtimer; 639} /* parsetime */ 640