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 /* System Headers */ 37 38 39 #include <sys/types.h> 40 #include <err.h> 41 #include <errno.h> 42 #include <stdio.h> 43 #include <stdlib.h> 44 #include <string.h> 45 #include <time.h> 46 #include <unistd.h> 47 #include <ctype.h> 48 #ifndef __FreeBSD__ 49 #include <getopt.h> 50 #endif 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 /* parse translation table - table driven parsers can be your FRIEND! 71 */ 72 struct { 73 char *name; /* token name */ 74 int value; /* token id */ 75 int plural; /* is this plural? */ 76 } Specials[] = { 77 { "midnight", MIDNIGHT,0 }, /* 00:00:00 of today or tomorrow */ 78 { "noon", NOON,0 }, /* 12:00:00 of today or tomorrow */ 79 { "teatime", TEATIME,0 }, /* 16:00:00 of today or tomorrow */ 80 { "am", AM,0 }, /* morning times for 0-12 clock */ 81 { "pm", PM,0 }, /* evening times for 0-12 clock */ 82 { "tomorrow", TOMORROW,0 }, /* execute 24 hours from time */ 83 { "today", TODAY, 0 }, /* execute today - don't advance time */ 84 { "now", NOW,0 }, /* opt prefix for PLUS */ 85 86 { "minute", MINUTES,0 }, /* minutes multiplier */ 87 { "minutes", MINUTES,1 }, /* (pluralized) */ 88 { "hour", HOURS,0 }, /* hours ... */ 89 { "hours", HOURS,1 }, /* (pluralized) */ 90 { "day", DAYS,0 }, /* days ... */ 91 { "days", DAYS,1 }, /* (pluralized) */ 92 { "week", WEEKS,0 }, /* week ... */ 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 } ; 133 134 /* File scope variables */ 135 136 static char **scp; /* scanner - pointer at arglist */ 137 static char scc; /* scanner - count of remaining arguments */ 138 static char *sct; /* scanner - next char pointer in current argument */ 139 static int need; /* scanner - need to advance to next argument */ 140 141 static char *sc_token; /* scanner - token buffer */ 142 static size_t sc_len; /* scanner - lenght of token buffer */ 143 static int sc_tokid; /* scanner - token id */ 144 static int sc_tokplur; /* scanner - is token plural? */ 145 146 static const char rcsid[] = 147 "$Id: parsetime.c,v 1.15 1998/08/30 17:33:05 steve Exp $"; 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 int 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 sc_token = (char *) mymalloc(sc_len); 184 } /* init_scanner */ 185 186 /* 187 * token() fetches a token from the input stream 188 */ 189 static int 190 token() 191 { 192 int idx; 193 194 while (1) { 195 memset(sc_token, 0, sc_len); 196 sc_tokid = EOF; 197 sc_tokplur = 0; 198 idx = 0; 199 200 /* if we need to read another argument, walk along the argument list; 201 * when we fall off the arglist, we'll just return EOF forever 202 */ 203 if (need) { 204 if (scc < 1) 205 return sc_tokid; 206 sct = *scp; 207 scp++; 208 scc--; 209 need = 0; 210 } 211 /* eat whitespace now - if we walk off the end of the argument, 212 * we'll continue, which puts us up at the top of the while loop 213 * to fetch the next argument in 214 */ 215 while (isspace(*sct)) 216 ++sct; 217 if (!*sct) { 218 need = 1; 219 continue; 220 } 221 222 /* preserve the first character of the new token 223 */ 224 sc_token[0] = *sct++; 225 226 /* then see what it is 227 */ 228 if (isdigit(sc_token[0])) { 229 while (isdigit(*sct)) 230 sc_token[++idx] = *sct++; 231 sc_token[++idx] = 0; 232 return sc_tokid = NUMBER; 233 } 234 else if (isalpha(sc_token[0])) { 235 while (isalpha(*sct)) 236 sc_token[++idx] = *sct++; 237 sc_token[++idx] = 0; 238 return parse_token(sc_token); 239 } 240 else if (sc_token[0] == ':' || sc_token[0] == '.') 241 return sc_tokid = DOT; 242 else if (sc_token[0] == '+') 243 return sc_tokid = PLUS; 244 else if (sc_token[0] == '/') 245 return sc_tokid = SLASH; 246 else 247 return sc_tokid = JUNK; 248 } /* while (1) */ 249 } /* token */ 250 251 252 /* 253 * plonk() gives an appropriate error message if a token is incorrect 254 */ 255 static void 256 plonk(int tok) 257 { 258 panic((tok == EOF) ? "incomplete time" 259 : "garbled time"); 260 } /* plonk */ 261 262 263 /* 264 * expect() gets a token and dies most horribly if it's not the token we want 265 */ 266 static void 267 expect(int desired) 268 { 269 if (token() != desired) 270 plonk(sc_tokid); /* and we die here... */ 271 } /* expect */ 272 273 274 /* 275 * dateadd() adds a number of minutes to a date. It is extraordinarily 276 * stupid regarding day-of-month overflow, and will most likely not 277 * work properly 278 */ 279 static void 280 dateadd(int minutes, struct tm *tm) 281 { 282 /* increment days */ 283 284 while (minutes > 24*60) { 285 minutes -= 24*60; 286 tm->tm_mday++; 287 } 288 289 /* increment hours */ 290 while (minutes > 60) { 291 minutes -= 60; 292 tm->tm_hour++; 293 if (tm->tm_hour > 23) { 294 tm->tm_mday++; 295 tm->tm_hour = 0; 296 } 297 } 298 299 /* increment minutes */ 300 tm->tm_min += minutes; 301 302 if (tm->tm_min > 59) { 303 tm->tm_hour++; 304 tm->tm_min -= 60; 305 306 if (tm->tm_hour > 23) { 307 tm->tm_mday++; 308 tm->tm_hour = 0; 309 } 310 } 311 } /* dateadd */ 312 313 314 /* 315 * plus() parses a now + time 316 * 317 * at [NOW] PLUS NUMBER [MINUTES|HOURS|DAYS|WEEKS] 318 * 319 */ 320 static void 321 plus(struct tm *tm) 322 { 323 int delay; 324 int expectplur; 325 326 expect(NUMBER); 327 328 delay = atoi(sc_token); 329 expectplur = (delay != 1) ? 1 : 0; 330 331 switch (token()) { 332 case WEEKS: 333 delay *= 7; 334 case DAYS: 335 delay *= 24; 336 case HOURS: 337 delay *= 60; 338 case MINUTES: 339 if (expectplur != sc_tokplur) 340 warnx("pluralization is wrong"); 341 dateadd(delay, tm); 342 return; 343 } 344 plonk(sc_tokid); 345 } /* plus */ 346 347 348 /* 349 * tod() computes the time of day 350 * [NUMBER [DOT NUMBER] [AM|PM]] 351 */ 352 static void 353 tod(struct tm *tm) 354 { 355 int hour, minute = 0; 356 int tlen; 357 358 hour = atoi(sc_token); 359 tlen = strlen(sc_token); 360 361 /* first pick out the time of day - if it's 4 digits, we assume 362 * a HHMM time, otherwise it's HH DOT MM time 363 */ 364 if (token() == DOT) { 365 expect(NUMBER); 366 minute = atoi(sc_token); 367 if (minute > 59) 368 panic("garbled time"); 369 token(); 370 } 371 else if (tlen == 4) { 372 minute = hour%100; 373 if (minute > 59) 374 panic("garbled time"); 375 hour = hour/100; 376 } 377 378 /* check if an AM or PM specifier was given 379 */ 380 if (sc_tokid == AM || sc_tokid == PM) { 381 if (hour > 12) 382 panic("garbled time"); 383 384 if (sc_tokid == PM) { 385 if (hour != 12) /* 12:xx PM is 12:xx, not 24:xx */ 386 hour += 12; 387 } else { 388 if (hour == 12) /* 12:xx AM is 00:xx, not 12:xx */ 389 hour = 0; 390 } 391 token(); 392 } 393 else if (hour > 23) 394 panic("garbled time"); 395 396 /* if we specify an absolute time, we don't want to bump the day even 397 * if we've gone past that time - but if we're specifying a time plus 398 * a relative offset, it's okay to bump things 399 */ 400 if ((sc_tokid == EOF || sc_tokid == PLUS) && tm->tm_hour > hour) { 401 tm->tm_mday++; 402 tm->tm_wday++; 403 } 404 405 tm->tm_hour = hour; 406 tm->tm_min = minute; 407 if (tm->tm_hour == 24) { 408 tm->tm_hour = 0; 409 tm->tm_mday++; 410 } 411 } /* tod */ 412 413 414 /* 415 * assign_date() assigns a date, wrapping to next year if needed 416 */ 417 static void 418 assign_date(struct tm *tm, long mday, long mon, long year) 419 { 420 if (year > 99) { 421 if (year > 1899) 422 year -= 1900; 423 else 424 panic("garbled time"); 425 } else if (year != -1) { 426 struct tm *lt; 427 time_t now; 428 429 time(&now); 430 lt = localtime(&now); 431 432 /* 433 * check if the specified year is in the next century. 434 * allow for one year of user error as many people will 435 * enter n - 1 at the start of year n. 436 */ 437 if (year < (lt->tm_year % 100) - 1) 438 year += 100; 439 /* adjust for the year 2000 and beyond */ 440 year += lt->tm_year - (lt->tm_year % 100); 441 } 442 443 if (year < 0 && 444 (tm->tm_mon > mon ||(tm->tm_mon == mon && tm->tm_mday > mday))) 445 year = tm->tm_year + 1; 446 447 tm->tm_mday = mday; 448 tm->tm_mon = mon; 449 450 if (year >= 0) 451 tm->tm_year = year; 452 } /* assign_date */ 453 454 455 /* 456 * month() picks apart a month specification 457 * 458 * /[<month> NUMBER [NUMBER]] \ 459 * |[TOMORROW] | 460 * |[DAY OF WEEK] | 461 * |NUMBER [SLASH NUMBER [SLASH NUMBER]]| 462 * \PLUS NUMBER MINUTES|HOURS|DAYS|WEEKS/ 463 */ 464 static void 465 month(struct tm *tm) 466 { 467 long year= (-1); 468 long mday = 0, wday, mon; 469 int tlen; 470 471 switch (sc_tokid) { 472 case PLUS: 473 plus(tm); 474 break; 475 476 case TOMORROW: 477 /* do something tomorrow */ 478 tm->tm_mday ++; 479 tm->tm_wday ++; 480 case TODAY: /* force ourselves to stay in today - no further processing */ 481 token(); 482 break; 483 484 case JAN: case FEB: case MAR: case APR: case MAY: case JUN: 485 case JUL: case AUG: case SEP: case OCT: case NOV: case DEC: 486 /* do month mday [year] 487 */ 488 mon = (sc_tokid-JAN); 489 expect(NUMBER); 490 mday = atol(sc_token); 491 if (token() == NUMBER) { 492 year = atol(sc_token); 493 token(); 494 } 495 assign_date(tm, mday, mon, year); 496 break; 497 498 case SUN: case MON: case TUE: 499 case WED: case THU: case FRI: 500 case SAT: 501 /* do a particular day of the week 502 */ 503 wday = (sc_tokid-SUN); 504 505 mday = tm->tm_mday; 506 507 /* if this day is < today, then roll to next week 508 */ 509 if (wday < tm->tm_wday) 510 mday += 7 - (tm->tm_wday - wday); 511 else 512 mday += (wday - tm->tm_wday); 513 514 tm->tm_wday = wday; 515 516 assign_date(tm, mday, tm->tm_mon, tm->tm_year); 517 break; 518 519 case NUMBER: 520 /* get numeric MMDDYY, mm/dd/yy, or dd.mm.yy 521 */ 522 tlen = strlen(sc_token); 523 mon = atol(sc_token); 524 token(); 525 526 if (sc_tokid == SLASH || sc_tokid == DOT) { 527 int sep; 528 529 sep = sc_tokid; 530 expect(NUMBER); 531 mday = atol(sc_token); 532 if (token() == sep) { 533 expect(NUMBER); 534 year = atol(sc_token); 535 token(); 536 } 537 538 /* flip months and days for european timing 539 */ 540 if (sep == DOT) { 541 int x = mday; 542 mday = mon; 543 mon = x; 544 } 545 } 546 else if (tlen == 6 || tlen == 8) { 547 if (tlen == 8) { 548 year = (mon % 10000) - 1900; 549 mon /= 10000; 550 } 551 else { 552 year = mon % 100; 553 mon /= 100; 554 } 555 mday = mon % 100; 556 mon /= 100; 557 } 558 else 559 panic("garbled time"); 560 561 mon--; 562 if (mon < 0 || mon > 11 || mday < 1 || mday > 31) 563 panic("garbled time"); 564 565 assign_date(tm, mday, mon, year); 566 break; 567 } /* case */ 568 } /* month */ 569 570 571 /* Global functions */ 572 573 time_t 574 parsetime(int argc, char **argv) 575 { 576 /* Do the argument parsing, die if necessary, and return the time the job 577 * should be run. 578 */ 579 time_t nowtimer, runtimer; 580 struct tm nowtime, runtime; 581 int hr = 0; 582 /* this MUST be initialized to zero for midnight/noon/teatime */ 583 584 nowtimer = time(NULL); 585 nowtime = *localtime(&nowtimer); 586 587 runtime = nowtime; 588 runtime.tm_sec = 0; 589 runtime.tm_isdst = 0; 590 591 if (argc <= optind) 592 usage(); 593 594 init_scanner(argc-optind, argv+optind); 595 596 switch (token()) { 597 case NOW: /* now is optional prefix for PLUS tree */ 598 expect(PLUS); 599 case PLUS: 600 plus(&runtime); 601 break; 602 603 case NUMBER: 604 tod(&runtime); 605 month(&runtime); 606 break; 607 608 /* evil coding for TEATIME|NOON|MIDNIGHT - we've initialised 609 * hr to zero up above, then fall into this case in such a 610 * way so we add +12 +4 hours to it for teatime, +12 hours 611 * to it for noon, and nothing at all for midnight, then 612 * set our runtime to that hour before leaping into the 613 * month scanner 614 */ 615 case TEATIME: 616 hr += 4; 617 case NOON: 618 hr += 12; 619 case MIDNIGHT: 620 if (runtime.tm_hour >= hr) { 621 runtime.tm_mday++; 622 runtime.tm_wday++; 623 } 624 runtime.tm_hour = hr; 625 runtime.tm_min = 0; 626 token(); 627 /* fall through to month setting */ 628 default: 629 month(&runtime); 630 break; 631 } /* ugly case statement */ 632 expect(EOF); 633 634 /* adjust for daylight savings time 635 */ 636 runtime.tm_isdst = -1; 637 runtimer = mktime(&runtime); 638 if (runtime.tm_isdst > 0) { 639 runtimer -= 3600; 640 runtimer = mktime(&runtime); 641 } 642 643 if (runtimer < 0) 644 panic("garbled time"); 645 646 if (nowtimer > runtimer) 647 panic("Trying to travel back in time"); 648 649 return runtimer; 650 } /* parsetime */ 651