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 1.27 2005/08/18 08:18:02 stefanf Exp $ 36 */ 37 38 /* System Headers */ 39 40 #include <sys/types.h> 41 #include <ctype.h> 42 #include <err.h> 43 #include <errno.h> 44 #include <stdio.h> 45 #include <stdlib.h> 46 #include <string.h> 47 #include <time.h> 48 #include <unistd.h> 49 50 /* Local headers */ 51 52 #include "at.h" 53 #include "panic.h" 54 #include "parsetime.h" 55 56 57 /* Structures and unions */ 58 59 enum { /* symbols */ 60 MIDNIGHT, NOON, TEATIME, 61 PM, AM, TOMORROW, TODAY, NOW, 62 MINUTES, HOURS, DAYS, WEEKS, MONTHS, YEARS, 63 NUMBER, PLUS, DOT, SLASH, ID, JUNK, 64 JAN, FEB, MAR, APR, MAY, JUN, 65 JUL, AUG, SEP, OCT, NOV, DEC, 66 SUN, MON, TUE, WED, THU, FRI, SAT 67 }; 68 69 /* parse translation table - table driven parsers can be your FRIEND! 70 */ 71 static const struct { 72 const char *name; /* token name */ 73 int value; /* token id */ 74 int plural; /* is this plural? */ 75 } Specials[] = { 76 { "midnight", MIDNIGHT,0 }, /* 00:00:00 of today or tomorrow */ 77 { "noon", NOON,0 }, /* 12:00:00 of today or tomorrow */ 78 { "teatime", TEATIME,0 }, /* 16:00:00 of today or tomorrow */ 79 { "am", AM,0 }, /* morning times for 0-12 clock */ 80 { "pm", PM,0 }, /* evening times for 0-12 clock */ 81 { "tomorrow", TOMORROW,0 }, /* execute 24 hours from time */ 82 { "today", TODAY, 0 }, /* execute today - don't advance time */ 83 { "now", NOW,0 }, /* opt prefix for PLUS */ 84 85 { "minute", MINUTES,0 }, /* minutes multiplier */ 86 { "minutes", MINUTES,1 }, /* (pluralized) */ 87 { "hour", HOURS,0 }, /* hours ... */ 88 { "hours", HOURS,1 }, /* (pluralized) */ 89 { "day", DAYS,0 }, /* days ... */ 90 { "days", DAYS,1 }, /* (pluralized) */ 91 { "week", WEEKS,0 }, /* week ... */ 92 { "weeks", WEEKS,1 }, /* (pluralized) */ 93 { "month", MONTHS,0 }, /* month ... */ 94 { "months", MONTHS,1 }, /* (pluralized) */ 95 { "year", YEARS,0 }, /* year ... */ 96 { "years", YEARS,1 }, /* (pluralized) */ 97 { "jan", JAN,0 }, 98 { "feb", FEB,0 }, 99 { "mar", MAR,0 }, 100 { "apr", APR,0 }, 101 { "may", MAY,0 }, 102 { "jun", JUN,0 }, 103 { "jul", JUL,0 }, 104 { "aug", AUG,0 }, 105 { "sep", SEP,0 }, 106 { "oct", OCT,0 }, 107 { "nov", NOV,0 }, 108 { "dec", DEC,0 }, 109 { "january", JAN,0 }, 110 { "february", FEB,0 }, 111 { "march", MAR,0 }, 112 { "april", APR,0 }, 113 { "may", MAY,0 }, 114 { "june", JUN,0 }, 115 { "july", JUL,0 }, 116 { "august", AUG,0 }, 117 { "september", SEP,0 }, 118 { "october", OCT,0 }, 119 { "november", NOV,0 }, 120 { "december", DEC,0 }, 121 { "sunday", SUN, 0 }, 122 { "sun", SUN, 0 }, 123 { "monday", MON, 0 }, 124 { "mon", MON, 0 }, 125 { "tuesday", TUE, 0 }, 126 { "tue", TUE, 0 }, 127 { "wednesday", WED, 0 }, 128 { "wed", WED, 0 }, 129 { "thursday", THU, 0 }, 130 { "thu", THU, 0 }, 131 { "friday", FRI, 0 }, 132 { "fri", FRI, 0 }, 133 { "saturday", SAT, 0 }, 134 { "sat", SAT, 0 }, 135 } ; 136 137 /* File scope variables */ 138 139 static char **scp; /* scanner - pointer at arglist */ 140 static char scc; /* scanner - count of remaining arguments */ 141 static char *sct; /* scanner - next char pointer in current argument */ 142 static int need; /* scanner - need to advance to next argument */ 143 144 static char *sc_token; /* scanner - token buffer */ 145 static size_t sc_len; /* scanner - length of token buffer */ 146 static int sc_tokid; /* scanner - token id */ 147 static int sc_tokplur; /* scanner - is token plural? */ 148 149 /* Local functions */ 150 151 /* 152 * parse a token, checking if it's something special to us 153 */ 154 static int 155 parse_token(char *arg) 156 { 157 size_t i; 158 159 for (i=0; i<(sizeof Specials/sizeof Specials[0]); i++) 160 if (strcasecmp(Specials[i].name, arg) == 0) { 161 sc_tokplur = Specials[i].plural; 162 return sc_tokid = Specials[i].value; 163 } 164 165 /* not special - must be some random id */ 166 return ID; 167 } /* parse_token */ 168 169 170 /* 171 * init_scanner() sets up the scanner to eat arguments 172 */ 173 static void 174 init_scanner(int argc, char **argv) 175 { 176 scp = argv; 177 scc = argc; 178 need = 1; 179 sc_len = 1; 180 while (argc-- > 0) 181 sc_len += strlen(*argv++); 182 183 if ((sc_token = malloc(sc_len)) == NULL) 184 errx(EXIT_FAILURE, "virtual memory exhausted"); 185 } /* init_scanner */ 186 187 /* 188 * token() fetches a token from the input stream 189 */ 190 static int 191 token(void) 192 { 193 int idx; 194 195 while (1) { 196 memset(sc_token, 0, sc_len); 197 sc_tokid = EOF; 198 sc_tokplur = 0; 199 idx = 0; 200 201 /* if we need to read another argument, walk along the argument list; 202 * when we fall off the arglist, we'll just return EOF forever 203 */ 204 if (need) { 205 if (scc < 1) 206 return sc_tokid; 207 sct = *scp; 208 scp++; 209 scc--; 210 need = 0; 211 } 212 /* eat whitespace now - if we walk off the end of the argument, 213 * we'll continue, which puts us up at the top of the while loop 214 * to fetch the next argument in 215 */ 216 while (isspace(*sct)) 217 ++sct; 218 if (!*sct) { 219 need = 1; 220 continue; 221 } 222 223 /* preserve the first character of the new token 224 */ 225 sc_token[0] = *sct++; 226 227 /* then see what it is 228 */ 229 if (isdigit(sc_token[0])) { 230 while (isdigit(*sct)) 231 sc_token[++idx] = *sct++; 232 sc_token[++idx] = 0; 233 return sc_tokid = NUMBER; 234 } 235 else if (isalpha(sc_token[0])) { 236 while (isalpha(*sct)) 237 sc_token[++idx] = *sct++; 238 sc_token[++idx] = 0; 239 return parse_token(sc_token); 240 } 241 else if (sc_token[0] == ':' || sc_token[0] == '.') 242 return sc_tokid = DOT; 243 else if (sc_token[0] == '+') 244 return sc_tokid = PLUS; 245 else if (sc_token[0] == '/') 246 return sc_tokid = SLASH; 247 else 248 return sc_tokid = JUNK; 249 } /* while (1) */ 250 } /* token */ 251 252 253 /* 254 * plonk() gives an appropriate error message if a token is incorrect 255 */ 256 static void 257 plonk(int tok) 258 { 259 panic((tok == EOF) ? "incomplete time" 260 : "garbled time"); 261 } /* plonk */ 262 263 264 /* 265 * expect() gets a token and dies most horribly if it's not the token we want 266 */ 267 static void 268 expect(int desired) 269 { 270 if (token() != desired) 271 plonk(sc_tokid); /* and we die here... */ 272 } /* expect */ 273 274 275 /* 276 * plus() parses a now + time 277 * 278 * at [NOW] PLUS NUMBER [MINUTES|HOURS|DAYS|WEEKS|MONTHS|YEARS] 279 * 280 */ 281 282 static void 283 plus(struct tm *tm) 284 { 285 int delay; 286 int expectplur; 287 288 expect(NUMBER); 289 290 delay = atoi(sc_token); 291 expectplur = (delay != 1) ? 1 : 0; 292 293 switch (token()) { 294 case YEARS: 295 tm->tm_year += delay; 296 break; 297 case MONTHS: 298 tm->tm_mon += delay; 299 break; 300 case WEEKS: 301 delay *= 7; 302 /* FALLTHROUGH */ 303 case DAYS: 304 tm->tm_mday += delay; 305 break; 306 case HOURS: 307 tm->tm_hour += delay; 308 break; 309 case MINUTES: 310 tm->tm_min += delay; 311 break; 312 default: 313 plonk(sc_tokid); 314 break; 315 } 316 317 if (expectplur != sc_tokplur) 318 warnx("pluralization is wrong"); 319 320 tm->tm_isdst = -1; 321 if (mktime(tm) < 0) 322 plonk(sc_tokid); 323 324 } /* plus */ 325 326 327 /* 328 * tod() computes the time of day 329 * [NUMBER [DOT NUMBER] [AM|PM]] 330 */ 331 static void 332 tod(struct tm *tm) 333 { 334 int hour, minute = 0; 335 int tlen; 336 337 hour = atoi(sc_token); 338 tlen = strlen(sc_token); 339 340 /* first pick out the time of day - if it's 4 digits, we assume 341 * a HHMM time, otherwise it's HH DOT MM time 342 */ 343 if (token() == DOT) { 344 expect(NUMBER); 345 minute = atoi(sc_token); 346 if (minute > 59) 347 panic("garbled time"); 348 token(); 349 } 350 else if (tlen == 4) { 351 minute = hour%100; 352 if (minute > 59) 353 panic("garbled time"); 354 hour = hour/100; 355 } 356 357 /* check if an AM or PM specifier was given 358 */ 359 if (sc_tokid == AM || sc_tokid == PM) { 360 if (hour > 12) 361 panic("garbled time"); 362 363 if (sc_tokid == PM) { 364 if (hour != 12) /* 12:xx PM is 12:xx, not 24:xx */ 365 hour += 12; 366 } else { 367 if (hour == 12) /* 12:xx AM is 00:xx, not 12:xx */ 368 hour = 0; 369 } 370 token(); 371 } 372 else if (hour > 23) 373 panic("garbled time"); 374 375 /* if we specify an absolute time, we don't want to bump the day even 376 * if we've gone past that time - but if we're specifying a time plus 377 * a relative offset, it's okay to bump things 378 */ 379 if ((sc_tokid == EOF || sc_tokid == PLUS) && tm->tm_hour > hour) { 380 tm->tm_mday++; 381 tm->tm_wday++; 382 } 383 384 tm->tm_hour = hour; 385 tm->tm_min = minute; 386 if (tm->tm_hour == 24) { 387 tm->tm_hour = 0; 388 tm->tm_mday++; 389 } 390 } /* tod */ 391 392 393 /* 394 * assign_date() assigns a date, wrapping to next year if needed 395 */ 396 static void 397 assign_date(struct tm *tm, long mday, long mon, long year) 398 { 399 400 /* 401 * Convert year into tm_year format (year - 1900). 402 * We may be given the year in 2 digit, 4 digit, or tm_year format. 403 */ 404 if (year != -1) { 405 if (year >= 1900) 406 year -= 1900; /* convert from 4 digit year */ 407 else if (year < 100) { 408 /* convert from 2 digit year */ 409 struct tm *lt; 410 time_t now; 411 412 time(&now); 413 lt = localtime(&now); 414 415 /* Convert to tm_year assuming current century */ 416 year += (lt->tm_year / 100) * 100; 417 418 if (year == lt->tm_year - 1) year++; 419 else if (year < lt->tm_year) 420 year += 100; /* must be in next century */ 421 } 422 } 423 424 if (year < 0 && 425 (tm->tm_mon > mon ||(tm->tm_mon == mon && tm->tm_mday > mday))) 426 year = tm->tm_year + 1; 427 428 tm->tm_mday = mday; 429 tm->tm_mon = mon; 430 431 if (year >= 0) 432 tm->tm_year = year; 433 } /* assign_date */ 434 435 436 /* 437 * month() picks apart a month specification 438 * 439 * /[<month> NUMBER [NUMBER]] \ 440 * |[TOMORROW] | 441 * |[DAY OF WEEK] | 442 * |NUMBER [SLASH NUMBER [SLASH NUMBER]]| 443 * \PLUS NUMBER MINUTES|HOURS|DAYS|WEEKS/ 444 */ 445 static void 446 month(struct tm *tm) 447 { 448 long year= (-1); 449 long mday = 0, wday, mon; 450 int tlen; 451 452 switch (sc_tokid) { 453 case PLUS: 454 plus(tm); 455 break; 456 457 case TOMORROW: 458 /* do something tomorrow */ 459 tm->tm_mday ++; 460 tm->tm_wday ++; 461 /* FALLTHROUGH */ 462 case TODAY: /* force ourselves to stay in today - no further processing */ 463 token(); 464 break; 465 466 case JAN: case FEB: case MAR: case APR: case MAY: case JUN: 467 case JUL: case AUG: case SEP: case OCT: case NOV: case DEC: 468 /* do month mday [year] 469 */ 470 mon = (sc_tokid-JAN); 471 expect(NUMBER); 472 mday = atol(sc_token); 473 if (token() == NUMBER) { 474 year = atol(sc_token); 475 token(); 476 } 477 assign_date(tm, mday, mon, year); 478 break; 479 480 case SUN: case MON: case TUE: 481 case WED: case THU: case FRI: 482 case SAT: 483 /* do a particular day of the week 484 */ 485 wday = (sc_tokid-SUN); 486 487 mday = tm->tm_mday; 488 489 /* if this day is < today, then roll to next week 490 */ 491 if (wday < tm->tm_wday) 492 mday += 7 - (tm->tm_wday - wday); 493 else 494 mday += (wday - tm->tm_wday); 495 496 tm->tm_wday = wday; 497 498 assign_date(tm, mday, tm->tm_mon, tm->tm_year); 499 break; 500 501 case NUMBER: 502 /* get numeric MMDDYY, mm/dd/yy, or dd.mm.yy 503 */ 504 tlen = strlen(sc_token); 505 mon = atol(sc_token); 506 token(); 507 508 if (sc_tokid == SLASH || sc_tokid == DOT) { 509 int sep; 510 511 sep = sc_tokid; 512 expect(NUMBER); 513 mday = atol(sc_token); 514 if (token() == sep) { 515 expect(NUMBER); 516 year = atol(sc_token); 517 token(); 518 } 519 520 /* flip months and days for European timing 521 */ 522 if (sep == DOT) { 523 int x = mday; 524 mday = mon; 525 mon = x; 526 } 527 } 528 else if (tlen == 6 || tlen == 8) { 529 if (tlen == 8) { 530 year = (mon % 10000) - 1900; 531 mon /= 10000; 532 } 533 else { 534 year = mon % 100; 535 mon /= 100; 536 } 537 mday = mon % 100; 538 mon /= 100; 539 } 540 else 541 panic("garbled time"); 542 543 mon--; 544 if (mon < 0 || mon > 11 || mday < 1 || mday > 31) 545 panic("garbled time"); 546 547 assign_date(tm, mday, mon, year); 548 break; 549 } /* case */ 550 } /* month */ 551 552 553 /* Global functions */ 554 555 time_t 556 parsetime(int argc, char **argv) 557 { 558 /* Do the argument parsing, die if necessary, and return the time the job 559 * should be run. 560 */ 561 time_t nowtimer, runtimer; 562 struct tm nowtime, runtime; 563 int hr = 0; 564 /* this MUST be initialized to zero for midnight/noon/teatime */ 565 566 nowtimer = time(NULL); 567 nowtime = *localtime(&nowtimer); 568 569 runtime = nowtime; 570 runtime.tm_sec = 0; 571 runtime.tm_isdst = 0; 572 573 if (argc <= optind) 574 usage(); 575 576 init_scanner(argc-optind, argv+optind); 577 578 switch (token()) { 579 case NOW: 580 if (scc < 1) { 581 return nowtimer; 582 } 583 /* now is optional prefix for PLUS tree */ 584 expect(PLUS); 585 /* FALLTHROUGH */ 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 /* FALLTHROUGH */ 605 case NOON: 606 hr += 12; 607 /* FALLTHROUGH */ 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 */ 617 default: 618 month(&runtime); 619 break; 620 } /* ugly case statement */ 621 expect(EOF); 622 623 /* convert back to time_t 624 */ 625 runtime.tm_isdst = -1; 626 runtimer = mktime(&runtime); 627 628 if (runtimer < 0) 629 panic("garbled time"); 630 631 if (nowtimer > runtimer) 632 panic("trying to travel back in time"); 633 634 return runtimer; 635 } /* parsetime */ 636