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 <errno.h> 41 #include <stdio.h> 42 #include <stdlib.h> 43 #include <string.h> 44 #include <time.h> 45 #include <unistd.h> 46 #include <ctype.h> 47 #ifndef __FreeBSD__ 48 #include <getopt.h> 49 #endif 50 51 /* Local headers */ 52 53 #include "at.h" 54 #include "panic.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, 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 struct { 72 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 { "jan", JAN,0 }, 94 { "feb", FEB,0 }, 95 { "mar", MAR,0 }, 96 { "apr", APR,0 }, 97 { "may", MAY,0 }, 98 { "jun", JUN,0 }, 99 { "jul", JUL,0 }, 100 { "aug", AUG,0 }, 101 { "sep", SEP,0 }, 102 { "oct", OCT,0 }, 103 { "nov", NOV,0 }, 104 { "dec", DEC,0 }, 105 { "sunday", SUN, 0 }, 106 { "sun", SUN, 0 }, 107 { "monday", MON, 0 }, 108 { "mon", MON, 0 }, 109 { "tuesday", TUE, 0 }, 110 { "tue", TUE, 0 }, 111 { "wednesday", WED, 0 }, 112 { "wed", WED, 0 }, 113 { "thursday", THU, 0 }, 114 { "thu", THU, 0 }, 115 { "friday", FRI, 0 }, 116 { "fri", FRI, 0 }, 117 { "saturday", SAT, 0 }, 118 { "sat", SAT, 0 }, 119 } ; 120 121 /* File scope variables */ 122 123 static char **scp; /* scanner - pointer at arglist */ 124 static char scc; /* scanner - count of remaining arguments */ 125 static char *sct; /* scanner - next char pointer in current argument */ 126 static int need; /* scanner - need to advance to next argument */ 127 128 static char *sc_token; /* scanner - token buffer */ 129 static size_t sc_len; /* scanner - lenght of token buffer */ 130 static int sc_tokid; /* scanner - token id */ 131 static int sc_tokplur; /* scanner - is token plural? */ 132 133 static char rcsid[] = "$Id: parsetime.c,v 1.1 1995/05/24 15:07:32 ig25 Exp $"; 134 135 /* Local functions */ 136 137 /* 138 * parse a token, checking if it's something special to us 139 */ 140 static int 141 parse_token(char *arg) 142 { 143 int i; 144 145 for (i=0; i<(sizeof Specials/sizeof Specials[0]); i++) 146 if (strcasecmp(Specials[i].name, arg) == 0) { 147 sc_tokplur = Specials[i].plural; 148 return sc_tokid = Specials[i].value; 149 } 150 151 /* not special - must be some random id */ 152 return ID; 153 } /* parse_token */ 154 155 156 /* 157 * init_scanner() sets up the scanner to eat arguments 158 */ 159 static void 160 init_scanner(int argc, char **argv) 161 { 162 scp = argv; 163 scc = argc; 164 need = 1; 165 sc_len = 1; 166 while (argc-- > 0) 167 sc_len += strlen(*argv++); 168 169 sc_token = (char *) mymalloc(sc_len); 170 } /* init_scanner */ 171 172 /* 173 * token() fetches a token from the input stream 174 */ 175 static int 176 token() 177 { 178 int idx; 179 180 while (1) { 181 memset(sc_token, 0, sc_len); 182 sc_tokid = EOF; 183 sc_tokplur = 0; 184 idx = 0; 185 186 /* if we need to read another argument, walk along the argument list; 187 * when we fall off the arglist, we'll just return EOF forever 188 */ 189 if (need) { 190 if (scc < 1) 191 return sc_tokid; 192 sct = *scp; 193 scp++; 194 scc--; 195 need = 0; 196 } 197 /* eat whitespace now - if we walk off the end of the argument, 198 * we'll continue, which puts us up at the top of the while loop 199 * to fetch the next argument in 200 */ 201 while (isspace(*sct)) 202 ++sct; 203 if (!*sct) { 204 need = 1; 205 continue; 206 } 207 208 /* preserve the first character of the new token 209 */ 210 sc_token[0] = *sct++; 211 212 /* then see what it is 213 */ 214 if (isdigit(sc_token[0])) { 215 while (isdigit(*sct)) 216 sc_token[++idx] = *sct++; 217 sc_token[++idx] = 0; 218 return sc_tokid = NUMBER; 219 } 220 else if (isalpha(sc_token[0])) { 221 while (isalpha(*sct)) 222 sc_token[++idx] = *sct++; 223 sc_token[++idx] = 0; 224 return parse_token(sc_token); 225 } 226 else if (sc_token[0] == ':' || sc_token[0] == '.') 227 return sc_tokid = DOT; 228 else if (sc_token[0] == '+') 229 return sc_tokid = PLUS; 230 else if (sc_token[0] == '/') 231 return sc_tokid = SLASH; 232 else 233 return sc_tokid = JUNK; 234 } /* while (1) */ 235 } /* token */ 236 237 238 /* 239 * plonk() gives an appropriate error message if a token is incorrect 240 */ 241 static void 242 plonk(int tok) 243 { 244 panic((tok == EOF) ? "incomplete time" 245 : "garbled time"); 246 } /* plonk */ 247 248 249 /* 250 * expect() gets a token and dies most horribly if it's not the token we want 251 */ 252 static void 253 expect(int desired) 254 { 255 if (token() != desired) 256 plonk(sc_tokid); /* and we die here... */ 257 } /* expect */ 258 259 260 /* 261 * dateadd() adds a number of minutes to a date. It is extraordinarily 262 * stupid regarding day-of-month overflow, and will most likely not 263 * work properly 264 */ 265 static void 266 dateadd(int minutes, struct tm *tm) 267 { 268 /* increment days */ 269 270 while (minutes > 24*60) { 271 minutes -= 24*60; 272 tm->tm_mday++; 273 } 274 275 /* increment hours */ 276 while (minutes > 60) { 277 minutes -= 60; 278 tm->tm_hour++; 279 if (tm->tm_hour > 23) { 280 tm->tm_mday++; 281 tm->tm_hour = 0; 282 } 283 } 284 285 /* increment minutes */ 286 tm->tm_min += minutes; 287 288 if (tm->tm_min > 59) { 289 tm->tm_hour++; 290 tm->tm_min -= 60; 291 292 if (tm->tm_hour > 23) { 293 tm->tm_mday++; 294 tm->tm_hour = 0; 295 } 296 } 297 } /* dateadd */ 298 299 300 /* 301 * plus() parses a now + time 302 * 303 * at [NOW] PLUS NUMBER [MINUTES|HOURS|DAYS|WEEKS] 304 * 305 */ 306 static void 307 plus(struct tm *tm) 308 { 309 int delay; 310 int expectplur; 311 312 expect(NUMBER); 313 314 delay = atoi(sc_token); 315 expectplur = (delay != 1) ? 1 : 0; 316 317 switch (token()) { 318 case WEEKS: 319 delay *= 7; 320 case DAYS: 321 delay *= 24; 322 case HOURS: 323 delay *= 60; 324 case MINUTES: 325 if (expectplur != sc_tokplur) 326 fprintf(stderr, "at: pluralization is wrong\n"); 327 dateadd(delay, tm); 328 return; 329 } 330 plonk(sc_tokid); 331 } /* plus */ 332 333 334 /* 335 * tod() computes the time of day 336 * [NUMBER [DOT NUMBER] [AM|PM]] 337 */ 338 static void 339 tod(struct tm *tm) 340 { 341 int hour, minute = 0; 342 int tlen; 343 344 hour = atoi(sc_token); 345 tlen = strlen(sc_token); 346 347 /* first pick out the time of day - if it's 4 digits, we assume 348 * a HHMM time, otherwise it's HH DOT MM time 349 */ 350 if (token() == DOT) { 351 expect(NUMBER); 352 minute = atoi(sc_token); 353 if (minute > 59) 354 panic("garbled time"); 355 token(); 356 } 357 else if (tlen == 4) { 358 minute = hour%100; 359 if (minute > 59) 360 panic("garbeld time"); 361 hour = hour/100; 362 } 363 364 /* check if an AM or PM specifier was given 365 */ 366 if (sc_tokid == AM || sc_tokid == PM) { 367 if (hour > 12) 368 panic("garbled time"); 369 370 if (sc_tokid == PM) 371 hour += 12; 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 if (year > 99) { 402 if (year > 1899) 403 year -= 1900; 404 else 405 panic("garbled time"); 406 } 407 408 if (year < 0 && 409 (tm->tm_mon > mon ||(tm->tm_mon == mon && tm->tm_mday > mday))) 410 year = tm->tm_year + 1; 411 412 tm->tm_mday = mday; 413 tm->tm_mon = mon; 414 415 if (year >= 0) 416 tm->tm_year = year; 417 } /* assign_date */ 418 419 420 /* 421 * month() picks apart a month specification 422 * 423 * /[<month> NUMBER [NUMBER]] \ 424 * |[TOMORROW] | 425 * |[DAY OF WEEK] | 426 * |NUMBER [SLASH NUMBER [SLASH NUMBER]]| 427 * \PLUS NUMBER MINUTES|HOURS|DAYS|WEEKS/ 428 */ 429 static void 430 month(struct tm *tm) 431 { 432 long year= (-1); 433 long mday, wday, mon; 434 int tlen; 435 436 switch (sc_tokid) { 437 case PLUS: 438 plus(tm); 439 break; 440 441 case TOMORROW: 442 /* do something tomorrow */ 443 tm->tm_mday ++; 444 tm->tm_wday ++; 445 case TODAY: /* force ourselves to stay in today - no further processing */ 446 token(); 447 break; 448 449 case JAN: case FEB: case MAR: case APR: case MAY: case JUN: 450 case JUL: case AUG: case SEP: case OCT: case NOV: case DEC: 451 /* do month mday [year] 452 */ 453 mon = (sc_tokid-JAN); 454 expect(NUMBER); 455 mday = atol(sc_token); 456 if (token() == NUMBER) { 457 year = atol(sc_token); 458 token(); 459 } 460 assign_date(tm, mday, mon, year); 461 break; 462 463 case SUN: case MON: case TUE: 464 case WED: case THU: case FRI: 465 case SAT: 466 /* do a particular day of the week 467 */ 468 wday = (sc_tokid-SUN); 469 470 mday = tm->tm_mday; 471 472 /* if this day is < today, then roll to next week 473 */ 474 if (wday < tm->tm_wday) 475 mday += 7 - (tm->tm_wday - wday); 476 else 477 mday += (wday - tm->tm_wday); 478 479 tm->tm_wday = wday; 480 481 assign_date(tm, mday, tm->tm_mon, tm->tm_year); 482 break; 483 484 case NUMBER: 485 /* get numeric MMDDYY, mm/dd/yy, or dd.mm.yy 486 */ 487 tlen = strlen(sc_token); 488 mon = atol(sc_token); 489 token(); 490 491 if (sc_tokid == SLASH || sc_tokid == DOT) { 492 int sep; 493 494 sep = sc_tokid; 495 expect(NUMBER); 496 mday = atol(sc_token); 497 if (token() == sep) { 498 expect(NUMBER); 499 year = atol(sc_token); 500 token(); 501 } 502 503 /* flip months and days for european timing 504 */ 505 if (sep == DOT) { 506 int x = mday; 507 mday = mon; 508 mon = x; 509 } 510 } 511 else if (tlen == 6 || tlen == 8) { 512 if (tlen == 8) { 513 year = (mon % 10000) - 1900; 514 mon /= 10000; 515 } 516 else { 517 year = mon % 100; 518 mon /= 100; 519 } 520 mday = mon % 100; 521 mon /= 100; 522 } 523 else 524 panic("garbled time"); 525 526 mon--; 527 if (mon < 0 || mon > 11 || mday < 1 || mday > 31) 528 panic("garbled time"); 529 530 assign_date(tm, mday, mon, year); 531 break; 532 } /* case */ 533 } /* month */ 534 535 536 /* Global functions */ 537 538 time_t 539 parsetime(int argc, char **argv) 540 { 541 /* Do the argument parsing, die if necessary, and return the time the job 542 * should be run. 543 */ 544 time_t nowtimer, runtimer; 545 struct tm nowtime, runtime; 546 int hr = 0; 547 /* this MUST be initialized to zero for midnight/noon/teatime */ 548 549 nowtimer = time(NULL); 550 nowtime = *localtime(&nowtimer); 551 552 runtime = nowtime; 553 runtime.tm_sec = 0; 554 runtime.tm_isdst = 0; 555 556 if (argc <= optind) 557 usage(); 558 559 init_scanner(argc-optind, argv+optind); 560 561 switch (token()) { 562 case NOW: /* now is optional prefix for PLUS tree */ 563 expect(PLUS); 564 case PLUS: 565 plus(&runtime); 566 break; 567 568 case NUMBER: 569 tod(&runtime); 570 month(&runtime); 571 break; 572 573 /* evil coding for TEATIME|NOON|MIDNIGHT - we've initialised 574 * hr to zero up above, then fall into this case in such a 575 * way so we add +12 +4 hours to it for teatime, +12 hours 576 * to it for noon, and nothing at all for midnight, then 577 * set our runtime to that hour before leaping into the 578 * month scanner 579 */ 580 case TEATIME: 581 hr += 4; 582 case NOON: 583 hr += 12; 584 case MIDNIGHT: 585 if (runtime.tm_hour >= hr) { 586 runtime.tm_mday++; 587 runtime.tm_wday++; 588 } 589 runtime.tm_hour = hr; 590 runtime.tm_min = 0; 591 token(); 592 /* fall through to month setting */ 593 default: 594 month(&runtime); 595 break; 596 } /* ugly case statement */ 597 expect(EOF); 598 599 /* adjust for daylight savings time 600 */ 601 runtime.tm_isdst = -1; 602 runtimer = mktime(&runtime); 603 if (runtime.tm_isdst > 0) { 604 runtimer -= 3600; 605 runtimer = mktime(&runtime); 606 } 607 608 if (runtimer < 0) 609 panic("garbled time"); 610 611 if (nowtimer > runtimer) 612 panic("Trying to travel back in time"); 613 614 return runtimer; 615 } /* parsetime */ 616