parsetime.c revision 54158
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#ifndef lint 37static const char rcsid[] = 38 "$FreeBSD: head/usr.bin/at/parsetime.c 54158 1999-12-05 19:57:14Z charnier $"; 39#endif /* not lint */ 40 41/* System Headers */ 42 43#include <sys/types.h> 44#include <ctype.h> 45#include <err.h> 46#include <errno.h> 47#include <stdio.h> 48#include <stdlib.h> 49#include <string.h> 50#include <time.h> 51#include <unistd.h> 52#ifndef __FreeBSD__ 53#include <getopt.h> 54#endif 55 56/* Local headers */ 57 58#include "at.h" 59#include "panic.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 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 int 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 sc_token = (char *) mymalloc(sc_len); 189} /* init_scanner */ 190 191/* 192 * token() fetches a token from the input stream 193 */ 194static int 195token() 196{ 197 int idx; 198 199 while (1) { 200 memset(sc_token, 0, sc_len); 201 sc_tokid = EOF; 202 sc_tokplur = 0; 203 idx = 0; 204 205 /* if we need to read another argument, walk along the argument list; 206 * when we fall off the arglist, we'll just return EOF forever 207 */ 208 if (need) { 209 if (scc < 1) 210 return sc_tokid; 211 sct = *scp; 212 scp++; 213 scc--; 214 need = 0; 215 } 216 /* eat whitespace now - if we walk off the end of the argument, 217 * we'll continue, which puts us up at the top of the while loop 218 * to fetch the next argument in 219 */ 220 while (isspace(*sct)) 221 ++sct; 222 if (!*sct) { 223 need = 1; 224 continue; 225 } 226 227 /* preserve the first character of the new token 228 */ 229 sc_token[0] = *sct++; 230 231 /* then see what it is 232 */ 233 if (isdigit(sc_token[0])) { 234 while (isdigit(*sct)) 235 sc_token[++idx] = *sct++; 236 sc_token[++idx] = 0; 237 return sc_tokid = NUMBER; 238 } 239 else if (isalpha(sc_token[0])) { 240 while (isalpha(*sct)) 241 sc_token[++idx] = *sct++; 242 sc_token[++idx] = 0; 243 return parse_token(sc_token); 244 } 245 else if (sc_token[0] == ':' || sc_token[0] == '.') 246 return sc_tokid = DOT; 247 else if (sc_token[0] == '+') 248 return sc_tokid = PLUS; 249 else if (sc_token[0] == '/') 250 return sc_tokid = SLASH; 251 else 252 return sc_tokid = JUNK; 253 } /* while (1) */ 254} /* token */ 255 256 257/* 258 * plonk() gives an appropriate error message if a token is incorrect 259 */ 260static void 261plonk(int tok) 262{ 263 panic((tok == EOF) ? "incomplete time" 264 : "garbled time"); 265} /* plonk */ 266 267 268/* 269 * expect() gets a token and dies most horribly if it's not the token we want 270 */ 271static void 272expect(int desired) 273{ 274 if (token() != desired) 275 plonk(sc_tokid); /* and we die here... */ 276} /* expect */ 277 278 279/* 280 * plus() parses a now + time 281 * 282 * at [NOW] PLUS NUMBER [MINUTES|HOURS|DAYS|WEEKS|MONTHS|YEARS] 283 * 284 */ 285 286static void 287plus(struct tm *tm) 288{ 289 int delay; 290 int expectplur; 291 292 expect(NUMBER); 293 294 delay = atoi(sc_token); 295 expectplur = (delay != 1) ? 1 : 0; 296 297 switch (token()) { 298 case YEARS: 299 tm->tm_year += delay; 300 break; 301 case MONTHS: 302 tm->tm_mon += delay; 303 break; 304 case WEEKS: 305 delay *= 7; 306 case DAYS: 307 tm->tm_mday += delay; 308 break; 309 case HOURS: 310 tm->tm_hour += delay; 311 break; 312 case MINUTES: 313 tm->tm_min += delay; 314 break; 315 default: 316 plonk(sc_tokid); 317 break; 318 } 319 320 if (expectplur != sc_tokplur) 321 warnx("pluralization is wrong"); 322 323 tm->tm_isdst = -1; 324 if (mktime(tm) < 0) 325 plonk(sc_tokid); 326 327} /* plus */ 328 329 330/* 331 * tod() computes the time of day 332 * [NUMBER [DOT NUMBER] [AM|PM]] 333 */ 334static void 335tod(struct tm *tm) 336{ 337 int hour, minute = 0; 338 int tlen; 339 340 hour = atoi(sc_token); 341 tlen = strlen(sc_token); 342 343 /* first pick out the time of day - if it's 4 digits, we assume 344 * a HHMM time, otherwise it's HH DOT MM time 345 */ 346 if (token() == DOT) { 347 expect(NUMBER); 348 minute = atoi(sc_token); 349 if (minute > 59) 350 panic("garbled time"); 351 token(); 352 } 353 else if (tlen == 4) { 354 minute = hour%100; 355 if (minute > 59) 356 panic("garbled time"); 357 hour = hour/100; 358 } 359 360 /* check if an AM or PM specifier was given 361 */ 362 if (sc_tokid == AM || sc_tokid == PM) { 363 if (hour > 12) 364 panic("garbled time"); 365 366 if (sc_tokid == PM) { 367 if (hour != 12) /* 12:xx PM is 12:xx, not 24:xx */ 368 hour += 12; 369 } else { 370 if (hour == 12) /* 12:xx AM is 00:xx, not 12:xx */ 371 hour = 0; 372 } 373 token(); 374 } 375 else if (hour > 23) 376 panic("garbled time"); 377 378 /* if we specify an absolute time, we don't want to bump the day even 379 * if we've gone past that time - but if we're specifying a time plus 380 * a relative offset, it's okay to bump things 381 */ 382 if ((sc_tokid == EOF || sc_tokid == PLUS) && tm->tm_hour > hour) { 383 tm->tm_mday++; 384 tm->tm_wday++; 385 } 386 387 tm->tm_hour = hour; 388 tm->tm_min = minute; 389 if (tm->tm_hour == 24) { 390 tm->tm_hour = 0; 391 tm->tm_mday++; 392 } 393} /* tod */ 394 395 396/* 397 * assign_date() assigns a date, wrapping to next year if needed 398 */ 399static void 400assign_date(struct tm *tm, long mday, long mon, long year) 401{ 402 if (year > 99) { 403 if (year > 1899) 404 year -= 1900; 405 else 406 panic("garbled time"); 407 } else if (year != -1) { 408 struct tm *lt; 409 time_t now; 410 411 time(&now); 412 lt = localtime(&now); 413 414 /* 415 * check if the specified year is in the next century. 416 * allow for one year of user error as many people will 417 * enter n - 1 at the start of year n. 418 */ 419 if (year < (lt->tm_year % 100) - 1) 420 year += 100; 421 /* adjust for the year 2000 and beyond */ 422 year += lt->tm_year - (lt->tm_year % 100); 423 } 424 425 if (year < 0 && 426 (tm->tm_mon > mon ||(tm->tm_mon == mon && tm->tm_mday > mday))) 427 year = tm->tm_year + 1; 428 429 tm->tm_mday = mday; 430 tm->tm_mon = mon; 431 432 if (year >= 0) 433 tm->tm_year = year; 434} /* assign_date */ 435 436 437/* 438 * month() picks apart a month specification 439 * 440 * /[<month> NUMBER [NUMBER]] \ 441 * |[TOMORROW] | 442 * |[DAY OF WEEK] | 443 * |NUMBER [SLASH NUMBER [SLASH NUMBER]]| 444 * \PLUS NUMBER MINUTES|HOURS|DAYS|WEEKS/ 445 */ 446static void 447month(struct tm *tm) 448{ 449 long year= (-1); 450 long mday = 0, wday, mon; 451 int tlen; 452 453 switch (sc_tokid) { 454 case PLUS: 455 plus(tm); 456 break; 457 458 case TOMORROW: 459 /* do something tomorrow */ 460 tm->tm_mday ++; 461 tm->tm_wday ++; 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 555time_t 556parsetime(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: /* now is optional prefix for PLUS tree */ 580 expect(PLUS); 581 case PLUS: 582 plus(&runtime); 583 break; 584 585 case NUMBER: 586 tod(&runtime); 587 month(&runtime); 588 break; 589 590 /* evil coding for TEATIME|NOON|MIDNIGHT - we've initialised 591 * hr to zero up above, then fall into this case in such a 592 * way so we add +12 +4 hours to it for teatime, +12 hours 593 * to it for noon, and nothing at all for midnight, then 594 * set our runtime to that hour before leaping into the 595 * month scanner 596 */ 597 case TEATIME: 598 hr += 4; 599 case NOON: 600 hr += 12; 601 case MIDNIGHT: 602 if (runtime.tm_hour >= hr) { 603 runtime.tm_mday++; 604 runtime.tm_wday++; 605 } 606 runtime.tm_hour = hr; 607 runtime.tm_min = 0; 608 token(); 609 /* FALLTHROUGH to month setting */ 610 default: 611 month(&runtime); 612 break; 613 } /* ugly case statement */ 614 expect(EOF); 615 616 /* adjust for daylight savings time 617 */ 618 runtime.tm_isdst = -1; 619 runtimer = mktime(&runtime); 620 if (runtime.tm_isdst > 0) { 621 runtimer -= 3600; 622 runtimer = mktime(&runtime); 623 } 624 625 if (runtimer < 0) 626 panic("garbled time"); 627 628 if (nowtimer > runtimer) 629 panic("trying to travel back in time"); 630 631 return runtimer; 632} /* parsetime */ 633