/usr.bin/at/parsetime.c
C | 670 lines | 439 code | 90 blank | 141 comment | 113 complexity | 4fd6be20a16b061b2016ee2d014049c2 MD5 | raw file
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__FBSDID("$FreeBSD$"); 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#include "parsetime.h" 59 60 61/* Structures and unions */ 62 63enum { /* symbols */ 64 MIDNIGHT, NOON, TEATIME, 65 PM, AM, TOMORROW, TODAY, NOW, 66 MINUTES, HOURS, DAYS, WEEKS, MONTHS, YEARS, 67 NUMBER, PLUS, MINUS, DOT, SLASH, ID, JUNK, 68 JAN, FEB, MAR, APR, MAY, JUN, 69 JUL, AUG, SEP, OCT, NOV, DEC, 70 SUN, MON, TUE, WED, THU, FRI, SAT 71 }; 72 73/* parse translation table - table driven parsers can be your FRIEND! 74 */ 75static const struct { 76 const char *name; /* token name */ 77 int value; /* token id */ 78 int plural; /* is this plural? */ 79} Specials[] = { 80 { "midnight", MIDNIGHT,0 }, /* 00:00:00 of today or tomorrow */ 81 { "noon", NOON,0 }, /* 12:00:00 of today or tomorrow */ 82 { "teatime", TEATIME,0 }, /* 16:00:00 of today or tomorrow */ 83 { "am", AM,0 }, /* morning times for 0-12 clock */ 84 { "pm", PM,0 }, /* evening times for 0-12 clock */ 85 { "tomorrow", TOMORROW,0 }, /* execute 24 hours from time */ 86 { "today", TODAY, 0 }, /* execute today - don't advance time */ 87 { "now", NOW,0 }, /* opt prefix for PLUS */ 88 89 { "minute", MINUTES,0 }, /* minutes multiplier */ 90 { "minutes", MINUTES,1 }, /* (pluralized) */ 91 { "hour", HOURS,0 }, /* hours ... */ 92 { "hours", HOURS,1 }, /* (pluralized) */ 93 { "day", DAYS,0 }, /* days ... */ 94 { "days", DAYS,1 }, /* (pluralized) */ 95 { "week", WEEKS,0 }, /* week ... */ 96 { "weeks", WEEKS,1 }, /* (pluralized) */ 97 { "month", MONTHS,0 }, /* month ... */ 98 { "months", MONTHS,1 }, /* (pluralized) */ 99 { "year", YEARS,0 }, /* year ... */ 100 { "years", YEARS,1 }, /* (pluralized) */ 101 { "jan", JAN,0 }, 102 { "feb", FEB,0 }, 103 { "mar", MAR,0 }, 104 { "apr", APR,0 }, 105 { "may", MAY,0 }, 106 { "jun", JUN,0 }, 107 { "jul", JUL,0 }, 108 { "aug", AUG,0 }, 109 { "sep", SEP,0 }, 110 { "oct", OCT,0 }, 111 { "nov", NOV,0 }, 112 { "dec", DEC,0 }, 113 { "january", JAN,0 }, 114 { "february", FEB,0 }, 115 { "march", MAR,0 }, 116 { "april", APR,0 }, 117 { "may", MAY,0 }, 118 { "june", JUN,0 }, 119 { "july", JUL,0 }, 120 { "august", AUG,0 }, 121 { "september", SEP,0 }, 122 { "october", OCT,0 }, 123 { "november", NOV,0 }, 124 { "december", DEC,0 }, 125 { "sunday", SUN, 0 }, 126 { "sun", SUN, 0 }, 127 { "monday", MON, 0 }, 128 { "mon", MON, 0 }, 129 { "tuesday", TUE, 0 }, 130 { "tue", TUE, 0 }, 131 { "wednesday", WED, 0 }, 132 { "wed", WED, 0 }, 133 { "thursday", THU, 0 }, 134 { "thu", THU, 0 }, 135 { "friday", FRI, 0 }, 136 { "fri", FRI, 0 }, 137 { "saturday", SAT, 0 }, 138 { "sat", SAT, 0 }, 139} ; 140 141/* File scope variables */ 142 143static char **scp; /* scanner - pointer at arglist */ 144static char scc; /* scanner - count of remaining arguments */ 145static char *sct; /* scanner - next char pointer in current argument */ 146static int need; /* scanner - need to advance to next argument */ 147 148static char *sc_token; /* scanner - token buffer */ 149static size_t sc_len; /* scanner - length of token buffer */ 150static int sc_tokid; /* scanner - token id */ 151static int sc_tokplur; /* scanner - is token plural? */ 152 153/* Local functions */ 154 155/* 156 * parse a token, checking if it's something special to us 157 */ 158static int 159parse_token(char *arg) 160{ 161 size_t i; 162 163 for (i=0; i<(sizeof Specials/sizeof Specials[0]); i++) 164 if (strcasecmp(Specials[i].name, arg) == 0) { 165 sc_tokplur = Specials[i].plural; 166 return sc_tokid = Specials[i].value; 167 } 168 169 /* not special - must be some random id */ 170 return ID; 171} /* parse_token */ 172 173 174/* 175 * init_scanner() sets up the scanner to eat arguments 176 */ 177static void 178init_scanner(int argc, char **argv) 179{ 180 scp = argv; 181 scc = argc; 182 need = 1; 183 sc_len = 1; 184 while (argc-- > 0) 185 sc_len += strlen(*argv++); 186 187 if ((sc_token = malloc(sc_len)) == NULL) 188 errx(EXIT_FAILURE, "virtual memory exhausted"); 189} /* init_scanner */ 190 191/* 192 * token() fetches a token from the input stream 193 */ 194static int 195token(void) 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 = MINUS; 251 else if (sc_token[0] == '/') 252 return sc_tokid = SLASH; 253 else 254 return sc_tokid = JUNK; 255 } /* while (1) */ 256} /* token */ 257 258 259/* 260 * plonk() gives an appropriate error message if a token is incorrect 261 */ 262static void 263plonk(int tok) 264{ 265 panic((tok == EOF) ? "incomplete time" 266 : "garbled time"); 267} /* plonk */ 268 269 270/* 271 * expect() gets a token and dies most horribly if it's not the token we want 272 */ 273static void 274expect(int desired) 275{ 276 if (token() != desired) 277 plonk(sc_tokid); /* and we die here... */ 278} /* expect */ 279 280 281/* 282 * plus_or_minus() holds functionality common to plus() and minus() 283 */ 284static void 285plus_or_minus(struct tm *tm, int delay) 286{ 287 int expectplur; 288 289 expectplur = (delay != 1 && delay != -1) ? 1 : 0; 290 291 switch (token()) { 292 case YEARS: 293 tm->tm_year += delay; 294 break; 295 case MONTHS: 296 tm->tm_mon += delay; 297 break; 298 case WEEKS: 299 delay *= 7; 300 case DAYS: 301 tm->tm_mday += delay; 302 break; 303 case HOURS: 304 tm->tm_hour += delay; 305 break; 306 case MINUTES: 307 tm->tm_min += delay; 308 break; 309 default: 310 plonk(sc_tokid); 311 break; 312 } 313 314 if (expectplur != sc_tokplur) 315 warnx("pluralization is wrong"); 316 317 tm->tm_isdst = -1; 318 if (mktime(tm) < 0) 319 plonk(sc_tokid); 320} /* plus_or_minus */ 321 322 323/* 324 * plus() parses a now + time 325 * 326 * at [NOW] PLUS NUMBER [MINUTES|HOURS|DAYS|WEEKS|MONTHS|YEARS] 327 * 328 */ 329static void 330plus(struct tm *tm) 331{ 332 int delay; 333 334 expect(NUMBER); 335 336 delay = atoi(sc_token); 337 plus_or_minus(tm, delay); 338} /* plus */ 339 340 341/* 342 * minus() is like plus but can not be used with NOW 343 */ 344static void 345minus(struct tm *tm) 346{ 347 int delay; 348 349 expect(NUMBER); 350 351 delay = -atoi(sc_token); 352 plus_or_minus(tm, delay); 353} /* minus */ 354 355 356/* 357 * tod() computes the time of day 358 * [NUMBER [DOT NUMBER] [AM|PM]] 359 */ 360static void 361tod(struct tm *tm) 362{ 363 int hour, minute = 0; 364 int tlen; 365 366 hour = atoi(sc_token); 367 tlen = strlen(sc_token); 368 369 /* first pick out the time of day - if it's 4 digits, we assume 370 * a HHMM time, otherwise it's HH DOT MM time 371 */ 372 if (token() == DOT) { 373 expect(NUMBER); 374 minute = atoi(sc_token); 375 if (minute > 59) 376 panic("garbled time"); 377 token(); 378 } 379 else if (tlen == 4) { 380 minute = hour%100; 381 if (minute > 59) 382 panic("garbled time"); 383 hour = hour/100; 384 } 385 386 /* check if an AM or PM specifier was given 387 */ 388 if (sc_tokid == AM || sc_tokid == PM) { 389 if (hour > 12) 390 panic("garbled time"); 391 392 if (sc_tokid == PM) { 393 if (hour != 12) /* 12:xx PM is 12:xx, not 24:xx */ 394 hour += 12; 395 } else { 396 if (hour == 12) /* 12:xx AM is 00:xx, not 12:xx */ 397 hour = 0; 398 } 399 token(); 400 } 401 else if (hour > 23) 402 panic("garbled time"); 403 404 /* if we specify an absolute time, we don't want to bump the day even 405 * if we've gone past that time - but if we're specifying a time plus 406 * a relative offset, it's okay to bump things 407 */ 408 if ((sc_tokid == EOF || sc_tokid == PLUS || sc_tokid == MINUS) && 409 tm->tm_hour > hour) { 410 tm->tm_mday++; 411 tm->tm_wday++; 412 } 413 414 tm->tm_hour = hour; 415 tm->tm_min = minute; 416 if (tm->tm_hour == 24) { 417 tm->tm_hour = 0; 418 tm->tm_mday++; 419 } 420} /* tod */ 421 422 423/* 424 * assign_date() assigns a date, wrapping to next year if needed 425 */ 426static void 427assign_date(struct tm *tm, long mday, long mon, long year) 428{ 429 430 /* 431 * Convert year into tm_year format (year - 1900). 432 * We may be given the year in 2 digit, 4 digit, or tm_year format. 433 */ 434 if (year != -1) { 435 if (year >= 1900) 436 year -= 1900; /* convert from 4 digit year */ 437 else if (year < 100) { 438 /* convert from 2 digit year */ 439 struct tm *lt; 440 time_t now; 441 442 time(&now); 443 lt = localtime(&now); 444 445 /* Convert to tm_year assuming current century */ 446 year += (lt->tm_year / 100) * 100; 447 448 if (year == lt->tm_year - 1) year++; 449 else if (year < lt->tm_year) 450 year += 100; /* must be in next century */ 451 } 452 } 453 454 if (year < 0 && 455 (tm->tm_mon > mon ||(tm->tm_mon == mon && tm->tm_mday > mday))) 456 year = tm->tm_year + 1; 457 458 tm->tm_mday = mday; 459 tm->tm_mon = mon; 460 461 if (year >= 0) 462 tm->tm_year = year; 463} /* assign_date */ 464 465 466/* 467 * month() picks apart a month specification 468 * 469 * /[<month> NUMBER [NUMBER]] \ 470 * |[TOMORROW] | 471 * |[DAY OF WEEK] | 472 * |NUMBER [SLASH NUMBER [SLASH NUMBER]]| 473 * \PLUS NUMBER MINUTES|HOURS|DAYS|WEEKS/ 474 */ 475static void 476month(struct tm *tm) 477{ 478 long year= (-1); 479 long mday = 0, wday, mon; 480 int tlen; 481 482 switch (sc_tokid) { 483 case PLUS: 484 plus(tm); 485 break; 486 case MINUS: 487 minus(tm); 488 break; 489 490 case TOMORROW: 491 /* do something tomorrow */ 492 tm->tm_mday ++; 493 tm->tm_wday ++; 494 case TODAY: /* force ourselves to stay in today - no further processing */ 495 token(); 496 break; 497 498 case JAN: case FEB: case MAR: case APR: case MAY: case JUN: 499 case JUL: case AUG: case SEP: case OCT: case NOV: case DEC: 500 /* do month mday [year] 501 */ 502 mon = (sc_tokid-JAN); 503 expect(NUMBER); 504 mday = atol(sc_token); 505 if (token() == NUMBER) { 506 year = atol(sc_token); 507 token(); 508 } 509 assign_date(tm, mday, mon, year); 510 break; 511 512 case SUN: case MON: case TUE: 513 case WED: case THU: case FRI: 514 case SAT: 515 /* do a particular day of the week 516 */ 517 wday = (sc_tokid-SUN); 518 519 mday = tm->tm_mday; 520 521 /* if this day is < today, then roll to next week 522 */ 523 if (wday < tm->tm_wday) 524 mday += 7 - (tm->tm_wday - wday); 525 else 526 mday += (wday - tm->tm_wday); 527 528 tm->tm_wday = wday; 529 530 assign_date(tm, mday, tm->tm_mon, tm->tm_year); 531 break; 532 533 case NUMBER: 534 /* get numeric MMDDYY, mm/dd/yy, or dd.mm.yy 535 */ 536 tlen = strlen(sc_token); 537 mon = atol(sc_token); 538 token(); 539 540 if (sc_tokid == SLASH || sc_tokid == DOT) { 541 int sep; 542 543 sep = sc_tokid; 544 expect(NUMBER); 545 mday = atol(sc_token); 546 if (token() == sep) { 547 expect(NUMBER); 548 year = atol(sc_token); 549 token(); 550 } 551 552 /* flip months and days for European timing 553 */ 554 if (sep == DOT) { 555 int x = mday; 556 mday = mon; 557 mon = x; 558 } 559 } 560 else if (tlen == 6 || tlen == 8) { 561 if (tlen == 8) { 562 year = (mon % 10000) - 1900; 563 mon /= 10000; 564 } 565 else { 566 year = mon % 100; 567 mon /= 100; 568 } 569 mday = mon % 100; 570 mon /= 100; 571 } 572 else 573 panic("garbled time"); 574 575 mon--; 576 if (mon < 0 || mon > 11 || mday < 1 || mday > 31) 577 panic("garbled time"); 578 579 assign_date(tm, mday, mon, year); 580 break; 581 } /* case */ 582} /* month */ 583 584 585/* Global functions */ 586 587time_t 588parsetime(int argc, char **argv) 589{ 590/* Do the argument parsing, die if necessary, and return the time the job 591 * should be run. 592 */ 593 time_t nowtimer, runtimer; 594 struct tm nowtime, runtime; 595 int hr = 0; 596 /* this MUST be initialized to zero for midnight/noon/teatime */ 597 598 nowtimer = time(NULL); 599 nowtime = *localtime(&nowtimer); 600 601 runtime = nowtime; 602 runtime.tm_sec = 0; 603 runtime.tm_isdst = 0; 604 605 if (argc <= optind) 606 usage(); 607 608 init_scanner(argc-optind, argv+optind); 609 610 switch (token()) { 611 case NOW: 612 if (scc < 1) { 613 return nowtimer; 614 } 615 /* now is optional prefix for PLUS tree */ 616 expect(PLUS); 617 case PLUS: 618 plus(&runtime); 619 break; 620 621 /* MINUS is different from PLUS in that NOW is not 622 * an optional prefix for it 623 */ 624 case MINUS: 625 minus(&runtime); 626 break; 627 case NUMBER: 628 tod(&runtime); 629 month(&runtime); 630 break; 631 632 /* evil coding for TEATIME|NOON|MIDNIGHT - we've initialised 633 * hr to zero up above, then fall into this case in such a 634 * way so we add +12 +4 hours to it for teatime, +12 hours 635 * to it for noon, and nothing at all for midnight, then 636 * set our runtime to that hour before leaping into the 637 * month scanner 638 */ 639 case TEATIME: 640 hr += 4; 641 case NOON: 642 hr += 12; 643 case MIDNIGHT: 644 if (runtime.tm_hour >= hr) { 645 runtime.tm_mday++; 646 runtime.tm_wday++; 647 } 648 runtime.tm_hour = hr; 649 runtime.tm_min = 0; 650 token(); 651 /* FALLTHROUGH to month setting */ 652 default: 653 month(&runtime); 654 break; 655 } /* ugly case statement */ 656 expect(EOF); 657 658 /* convert back to time_t 659 */ 660 runtime.tm_isdst = -1; 661 runtimer = mktime(&runtime); 662 663 if (runtimer < 0) 664 panic("garbled time"); 665 666 if (nowtimer > runtimer) 667 panic("trying to travel back in time"); 668 669 return runtimer; 670} /* parsetime */