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 * $FreeBSD: src/usr.bin/at/parsetime.c,v 1.19.2.3 2001/12/19 11:19:16 brian Exp $ 36 * $DragonFly: src/usr.bin/at/parsetime.c,v 1.2 2003/06/17 04:29:25 dillon Exp $ 37 */ 38 39 /* System Headers */ 40 41 #include <sys/types.h> 42 #include <ctype.h> 43 #include <err.h> 44 #include <errno.h> 45 #include <stdio.h> 46 #include <stdlib.h> 47 #include <string.h> 48 #include <time.h> 49 #include <unistd.h> 50 #ifndef __FreeBSD__ 51 #include <getopt.h> 52 #endif 53 54 /* Local headers */ 55 56 #include "at.h" 57 #include "panic.h" 58 59 60 /* Structures and unions */ 61 62 enum { /* symbols */ 63 MIDNIGHT, NOON, TEATIME, 64 PM, AM, TOMORROW, TODAY, NOW, 65 MINUTES, HOURS, DAYS, WEEKS, MONTHS, YEARS, 66 NUMBER, PLUS, DOT, SLASH, ID, JUNK, 67 JAN, FEB, MAR, APR, MAY, JUN, 68 JUL, AUG, SEP, OCT, NOV, DEC, 69 SUN, MON, TUE, WED, THU, FRI, SAT 70 }; 71 72 /* parse translation table - table driven parsers can be your FRIEND! 73 */ 74 struct { 75 char *name; /* token name */ 76 int value; /* token id */ 77 int plural; /* is this plural? */ 78 } Specials[] = { 79 { "midnight", MIDNIGHT,0 }, /* 00:00:00 of today or tomorrow */ 80 { "noon", NOON,0 }, /* 12:00:00 of today or tomorrow */ 81 { "teatime", TEATIME,0 }, /* 16:00:00 of today or tomorrow */ 82 { "am", AM,0 }, /* morning times for 0-12 clock */ 83 { "pm", PM,0 }, /* evening times for 0-12 clock */ 84 { "tomorrow", TOMORROW,0 }, /* execute 24 hours from time */ 85 { "today", TODAY, 0 }, /* execute today - don't advance time */ 86 { "now", NOW,0 }, /* opt prefix for PLUS */ 87 88 { "minute", MINUTES,0 }, /* minutes multiplier */ 89 { "minutes", MINUTES,1 }, /* (pluralized) */ 90 { "hour", HOURS,0 }, /* hours ... */ 91 { "hours", HOURS,1 }, /* (pluralized) */ 92 { "day", DAYS,0 }, /* days ... */ 93 { "days", DAYS,1 }, /* (pluralized) */ 94 { "week", WEEKS,0 }, /* week ... */ 95 { "weeks", WEEKS,1 }, /* (pluralized) */ 96 { "month", MONTHS,0 }, /* month ... */ 97 { "months", MONTHS,1 }, /* (pluralized) */ 98 { "year", YEARS,0 }, /* year ... */ 99 { "years", YEARS,1 }, /* (pluralized) */ 100 { "jan", JAN,0 }, 101 { "feb", FEB,0 }, 102 { "mar", MAR,0 }, 103 { "apr", APR,0 }, 104 { "may", MAY,0 }, 105 { "jun", JUN,0 }, 106 { "jul", JUL,0 }, 107 { "aug", AUG,0 }, 108 { "sep", SEP,0 }, 109 { "oct", OCT,0 }, 110 { "nov", NOV,0 }, 111 { "dec", DEC,0 }, 112 { "january", JAN,0 }, 113 { "february", FEB,0 }, 114 { "march", MAR,0 }, 115 { "april", APR,0 }, 116 { "may", MAY,0 }, 117 { "june", JUN,0 }, 118 { "july", JUL,0 }, 119 { "august", AUG,0 }, 120 { "september", SEP,0 }, 121 { "october", OCT,0 }, 122 { "november", NOV,0 }, 123 { "december", DEC,0 }, 124 { "sunday", SUN, 0 }, 125 { "sun", SUN, 0 }, 126 { "monday", MON, 0 }, 127 { "mon", MON, 0 }, 128 { "tuesday", TUE, 0 }, 129 { "tue", TUE, 0 }, 130 { "wednesday", WED, 0 }, 131 { "wed", WED, 0 }, 132 { "thursday", THU, 0 }, 133 { "thu", THU, 0 }, 134 { "friday", FRI, 0 }, 135 { "fri", FRI, 0 }, 136 { "saturday", SAT, 0 }, 137 { "sat", SAT, 0 }, 138 } ; 139 140 /* File scope variables */ 141 142 static char **scp; /* scanner - pointer at arglist */ 143 static char 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 */ 146 147 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 /* Local functions */ 153 154 /* 155 * parse a token, checking if it's something special to us 156 */ 157 static int 158 parse_token(char *arg) 159 { 160 int i; 161 162 for (i=0; i<(sizeof Specials/sizeof Specials[0]); i++) 163 if (strcasecmp(Specials[i].name, arg) == 0) { 164 sc_tokplur = Specials[i].plural; 165 return sc_tokid = Specials[i].value; 166 } 167 168 /* not special - must be some random id */ 169 return ID; 170 } /* parse_token */ 171 172 173 /* 174 * init_scanner() sets up the scanner to eat arguments 175 */ 176 static void 177 init_scanner(int argc, char **argv) 178 { 179 scp = argv; 180 scc = argc; 181 need = 1; 182 sc_len = 1; 183 while (argc-- > 0) 184 sc_len += strlen(*argv++); 185 186 if ((sc_token = malloc(sc_len)) == NULL) 187 errx(EXIT_FAILURE, "virtual memory exhausted"); 188 } /* init_scanner */ 189 190 /* 191 * token() fetches a token from the input stream 192 */ 193 static int 194 token() 195 { 196 int idx; 197 198 while (1) { 199 memset(sc_token, 0, sc_len); 200 sc_tokid = EOF; 201 sc_tokplur = 0; 202 idx = 0; 203 204 /* if we need to read another argument, walk along the argument list; 205 * when we fall off the arglist, we'll 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 /* eat whitespace now - if we walk off the end of the argument, 216 * we'll continue, which puts us up at the top of the while loop 217 * to fetch the next argument in 218 */ 219 while (isspace(*sct)) 220 ++sct; 221 if (!*sct) { 222 need = 1; 223 continue; 224 } 225 226 /* preserve the first character of the new token 227 */ 228 sc_token[0] = *sct++; 229 230 /* then see what it is 231 */ 232 if (isdigit(sc_token[0])) { 233 while (isdigit(*sct)) 234 sc_token[++idx] = *sct++; 235 sc_token[++idx] = 0; 236 return sc_tokid = NUMBER; 237 } 238 else if (isalpha(sc_token[0])) { 239 while (isalpha(*sct)) 240 sc_token[++idx] = *sct++; 241 sc_token[++idx] = 0; 242 return parse_token(sc_token); 243 } 244 else if (sc_token[0] == ':' || sc_token[0] == '.') 245 return sc_tokid = DOT; 246 else if (sc_token[0] == '+') 247 return sc_tokid = PLUS; 248 else if (sc_token[0] == '/') 249 return sc_tokid = SLASH; 250 else 251 return sc_tokid = JUNK; 252 } /* while (1) */ 253 } /* token */ 254 255 256 /* 257 * plonk() gives an appropriate error message if a token is incorrect 258 */ 259 static void 260 plonk(int tok) 261 { 262 panic((tok == EOF) ? "incomplete time" 263 : "garbled time"); 264 } /* plonk */ 265 266 267 /* 268 * expect() gets a token and dies most horribly if it's not the token we want 269 */ 270 static void 271 expect(int desired) 272 { 273 if (token() != desired) 274 plonk(sc_tokid); /* and we die here... */ 275 } /* expect */ 276 277 278 /* 279 * plus() parses a now + time 280 * 281 * at [NOW] PLUS NUMBER [MINUTES|HOURS|DAYS|WEEKS|MONTHS|YEARS] 282 * 283 */ 284 285 static void 286 plus(struct tm *tm) 287 { 288 int delay; 289 int expectplur; 290 291 expect(NUMBER); 292 293 delay = atoi(sc_token); 294 expectplur = (delay != 1) ? 1 : 0; 295 296 switch (token()) { 297 case YEARS: 298 tm->tm_year += delay; 299 break; 300 case MONTHS: 301 tm->tm_mon += delay; 302 break; 303 case WEEKS: 304 delay *= 7; 305 case DAYS: 306 tm->tm_mday += delay; 307 break; 308 case HOURS: 309 tm->tm_hour += delay; 310 break; 311 case MINUTES: 312 tm->tm_min += delay; 313 break; 314 default: 315 plonk(sc_tokid); 316 break; 317 } 318 319 if (expectplur != sc_tokplur) 320 warnx("pluralization is wrong"); 321 322 tm->tm_isdst = -1; 323 if (mktime(tm) < 0) 324 plonk(sc_tokid); 325 326 } /* plus */ 327 328 329 /* 330 * tod() computes the time of day 331 * [NUMBER [DOT NUMBER] [AM|PM]] 332 */ 333 static void 334 tod(struct tm *tm) 335 { 336 int hour, minute = 0; 337 int tlen; 338 339 hour = atoi(sc_token); 340 tlen = strlen(sc_token); 341 342 /* first pick out the time of day - if it's 4 digits, we assume 343 * a HHMM time, otherwise it's HH DOT MM time 344 */ 345 if (token() == DOT) { 346 expect(NUMBER); 347 minute = atoi(sc_token); 348 if (minute > 59) 349 panic("garbled time"); 350 token(); 351 } 352 else if (tlen == 4) { 353 minute = hour%100; 354 if (minute > 59) 355 panic("garbled time"); 356 hour = hour/100; 357 } 358 359 /* check if an AM or PM specifier was given 360 */ 361 if (sc_tokid == AM || sc_tokid == PM) { 362 if (hour > 12) 363 panic("garbled time"); 364 365 if (sc_tokid == PM) { 366 if (hour != 12) /* 12:xx PM is 12:xx, not 24:xx */ 367 hour += 12; 368 } else { 369 if (hour == 12) /* 12:xx AM is 00:xx, not 12:xx */ 370 hour = 0; 371 } 372 token(); 373 } 374 else if (hour > 23) 375 panic("garbled time"); 376 377 /* if we specify an absolute time, we don't want to bump the day even 378 * if we've gone past that time - but if we're specifying a time plus 379 * a relative offset, it's okay to bump things 380 */ 381 if ((sc_tokid == EOF || sc_tokid == PLUS) && tm->tm_hour > hour) { 382 tm->tm_mday++; 383 tm->tm_wday++; 384 } 385 386 tm->tm_hour = hour; 387 tm->tm_min = minute; 388 if (tm->tm_hour == 24) { 389 tm->tm_hour = 0; 390 tm->tm_mday++; 391 } 392 } /* tod */ 393 394 395 /* 396 * assign_date() assigns a date, wrapping to next year if needed 397 */ 398 static void 399 assign_date(struct tm *tm, long mday, long mon, long year) 400 { 401 402 /* 403 * Convert year into tm_year format (year - 1900). 404 * We may be given the year in 2 digit, 4 digit, or tm_year format. 405 */ 406 if (year != -1) { 407 if (year >= 1900) 408 year -= 1900; /* convert from 4 digit year */ 409 else if (year < 100) { 410 /* convert from 2 digit year */ 411 struct tm *lt; 412 time_t now; 413 414 time(&now); 415 lt = localtime(&now); 416 417 /* Convert to tm_year assuming current century */ 418 year += (lt->tm_year / 100) * 100; 419 420 if (year == lt->tm_year - 1) year++; 421 else if (year < lt->tm_year) 422 year += 100; /* must be in next century */ 423 } 424 } 425 426 if (year < 0 && 427 (tm->tm_mon > mon ||(tm->tm_mon == mon && tm->tm_mday > mday))) 428 year = tm->tm_year + 1; 429 430 tm->tm_mday = mday; 431 tm->tm_mon = mon; 432 433 if (year >= 0) 434 tm->tm_year = year; 435 } /* assign_date */ 436 437 438 /* 439 * month() picks apart a month specification 440 * 441 * /[<month> NUMBER [NUMBER]] \ 442 * |[TOMORROW] | 443 * |[DAY OF WEEK] | 444 * |NUMBER [SLASH NUMBER [SLASH NUMBER]]| 445 * \PLUS NUMBER MINUTES|HOURS|DAYS|WEEKS/ 446 */ 447 static void 448 month(struct tm *tm) 449 { 450 long year= (-1); 451 long mday = 0, wday, mon; 452 int tlen; 453 454 switch (sc_tokid) { 455 case PLUS: 456 plus(tm); 457 break; 458 459 case TOMORROW: 460 /* do something tomorrow */ 461 tm->tm_mday ++; 462 tm->tm_wday ++; 463 case TODAY: /* force ourselves to stay in today - no further processing */ 464 token(); 465 break; 466 467 case JAN: case FEB: case MAR: case APR: case MAY: case JUN: 468 case JUL: case AUG: case SEP: case OCT: case NOV: case DEC: 469 /* do month mday [year] 470 */ 471 mon = (sc_tokid-JAN); 472 expect(NUMBER); 473 mday = atol(sc_token); 474 if (token() == NUMBER) { 475 year = atol(sc_token); 476 token(); 477 } 478 assign_date(tm, mday, mon, year); 479 break; 480 481 case SUN: case MON: case TUE: 482 case WED: case THU: case FRI: 483 case SAT: 484 /* do a particular day of the week 485 */ 486 wday = (sc_tokid-SUN); 487 488 mday = tm->tm_mday; 489 490 /* if this day is < today, then roll to next week 491 */ 492 if (wday < tm->tm_wday) 493 mday += 7 - (tm->tm_wday - wday); 494 else 495 mday += (wday - tm->tm_wday); 496 497 tm->tm_wday = wday; 498 499 assign_date(tm, mday, tm->tm_mon, tm->tm_year); 500 break; 501 502 case NUMBER: 503 /* get numeric MMDDYY, mm/dd/yy, or dd.mm.yy 504 */ 505 tlen = strlen(sc_token); 506 mon = atol(sc_token); 507 token(); 508 509 if (sc_tokid == SLASH || sc_tokid == DOT) { 510 int sep; 511 512 sep = sc_tokid; 513 expect(NUMBER); 514 mday = atol(sc_token); 515 if (token() == sep) { 516 expect(NUMBER); 517 year = atol(sc_token); 518 token(); 519 } 520 521 /* flip months and days for European timing 522 */ 523 if (sep == DOT) { 524 int x = mday; 525 mday = mon; 526 mon = x; 527 } 528 } 529 else if (tlen == 6 || tlen == 8) { 530 if (tlen == 8) { 531 year = (mon % 10000) - 1900; 532 mon /= 10000; 533 } 534 else { 535 year = mon % 100; 536 mon /= 100; 537 } 538 mday = mon % 100; 539 mon /= 100; 540 } 541 else 542 panic("garbled time"); 543 544 mon--; 545 if (mon < 0 || mon > 11 || mday < 1 || mday > 31) 546 panic("garbled time"); 547 548 assign_date(tm, mday, mon, year); 549 break; 550 } /* case */ 551 } /* month */ 552 553 554 /* Global functions */ 555 556 time_t 557 parsetime(int argc, char **argv) 558 { 559 /* Do the argument parsing, die if necessary, and return the time the job 560 * should be run. 561 */ 562 time_t nowtimer, runtimer; 563 struct tm nowtime, runtime; 564 int hr = 0; 565 /* this MUST be initialized to zero for midnight/noon/teatime */ 566 567 nowtimer = time(NULL); 568 nowtime = *localtime(&nowtimer); 569 570 runtime = nowtime; 571 runtime.tm_sec = 0; 572 runtime.tm_isdst = 0; 573 574 if (argc <= optind) 575 usage(); 576 577 init_scanner(argc-optind, argv+optind); 578 579 switch (token()) { 580 case NOW: 581 if (scc < 1) { 582 return nowtimer; 583 } 584 /* now is optional prefix for PLUS tree */ 585 expect(PLUS); 586 case PLUS: 587 plus(&runtime); 588 break; 589 590 case NUMBER: 591 tod(&runtime); 592 month(&runtime); 593 break; 594 595 /* evil coding for TEATIME|NOON|MIDNIGHT - we've initialised 596 * hr to zero up above, then fall into this case in such a 597 * way so we add +12 +4 hours to it for teatime, +12 hours 598 * to it for noon, and nothing at all for midnight, then 599 * set our runtime to that hour before leaping into the 600 * month scanner 601 */ 602 case TEATIME: 603 hr += 4; 604 case NOON: 605 hr += 12; 606 case MIDNIGHT: 607 if (runtime.tm_hour >= hr) { 608 runtime.tm_mday++; 609 runtime.tm_wday++; 610 } 611 runtime.tm_hour = hr; 612 runtime.tm_min = 0; 613 token(); 614 /* FALLTHROUGH to month setting */ 615 default: 616 month(&runtime); 617 break; 618 } /* ugly case statement */ 619 expect(EOF); 620 621 /* adjust for daylight savings time 622 */ 623 runtime.tm_isdst = -1; 624 runtimer = mktime(&runtime); 625 if (runtime.tm_isdst > 0) { 626 runtimer -= 3600; 627 runtimer = mktime(&runtime); 628 } 629 630 if (runtimer < 0) 631 panic("garbled time"); 632 633 if (nowtimer > runtimer) 634 panic("trying to travel back in time"); 635 636 return runtimer; 637 } /* parsetime */ 638