1 /* $NetBSD: parsetime.c,v 1.3 1995/03/25 18:13:36 glass Exp $ */ 2 3 /* 4 * parsetime.c - parse time for at(1) 5 * Copyright (C) 1993 Thomas Koenig 6 * 7 * modifications for english-language times 8 * Copyright (C) 1993 David Parsons 9 * All rights reserved. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. The name of the author(s) may not be used to endorse or promote 17 * products derived from this software without specific prior written 18 * permission. 19 * 20 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR 21 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 22 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 23 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 24 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 25 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 * THEORY OF LIABILITY, WETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 29 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 * 31 * at [NOW] PLUS NUMBER MINUTES|HOURS|DAYS|WEEKS 32 * /NUMBER [DOT NUMBER] [AM|PM]\ /[MONTH NUMBER [NUMBER]] \ 33 * |NOON | |[TOMORROW] | 34 * |MIDNIGHT | |NUMBER [SLASH NUMBER [SLASH NUMBER]]| 35 * \TEATIME / \PLUS NUMBER MINUTES|HOURS|DAYS|WEEKS/ 36 */ 37 38 /* System Headers */ 39 40 #include <sys/types.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 49 /* Local headers */ 50 51 #include "at.h" 52 #include "panic.h" 53 54 55 /* Structures and unions */ 56 57 enum { /* symbols */ 58 MIDNIGHT, NOON, TEATIME, 59 PM, AM, TOMORROW, TODAY, NOW, 60 MINUTES, HOURS, DAYS, WEEKS, 61 NUMBER, PLUS, DOT, SLASH, ID, JUNK, 62 JAN, FEB, MAR, APR, MAY, JUN, 63 JUL, AUG, SEP, OCT, NOV, DEC 64 }; 65 66 /* 67 * parse translation table - table driven parsers can be your FRIEND! 68 */ 69 struct { 70 char *name; /* token name */ 71 int value; /* token id */ 72 } Specials[] = { 73 { "midnight", MIDNIGHT }, /* 00:00:00 of today or tomorrow */ 74 { "noon", NOON }, /* 12:00:00 of today or tomorrow */ 75 { "teatime", TEATIME }, /* 16:00:00 of today or tomorrow */ 76 { "am", AM }, /* morning times for 0-12 clock */ 77 { "pm", PM }, /* evening times for 0-12 clock */ 78 { "tomorrow", TOMORROW }, /* execute 24 hours from time */ 79 { "today", TODAY }, /* execute today - don't advance time */ 80 { "now", NOW }, /* opt prefix for PLUS */ 81 82 { "minute", MINUTES }, /* minutes multiplier */ 83 { "min", MINUTES }, 84 { "m", MINUTES }, 85 { "minutes", MINUTES }, /* (pluralized) */ 86 { "hour", HOURS }, /* hours ... */ 87 { "hr", HOURS }, /* abbreviated */ 88 { "h", HOURS }, 89 { "hours", HOURS }, /* (pluralized) */ 90 { "day", DAYS }, /* days ... */ 91 { "d", DAYS }, 92 { "days", DAYS }, /* (pluralized) */ 93 { "week", WEEKS }, /* week ... */ 94 { "w", WEEKS }, 95 { "weeks", WEEKS }, /* (pluralized) */ 96 { "jan", JAN }, 97 { "feb", FEB }, 98 { "mar", MAR }, 99 { "apr", APR }, 100 { "may", MAY }, 101 { "jun", JUN }, 102 { "jul", JUL }, 103 { "aug", AUG }, 104 { "sep", SEP }, 105 { "oct", OCT }, 106 { "nov", NOV }, 107 { "dec", DEC } 108 } ; 109 110 /* File scope variables */ 111 112 static char **scp; /* scanner - pointer at arglist */ 113 static char scc; /* scanner - count of remaining arguments */ 114 static char *sct; /* scanner - next char pointer in current argument */ 115 static int need; /* scanner - need to advance to next argument */ 116 117 static char *sc_token; /* scanner - token buffer */ 118 static size_t sc_len; /* scanner - lenght of token buffer */ 119 static int sc_tokid; /* scanner - token id */ 120 121 #ifndef lint 122 static char rcsid[] = "$NetBSD: parsetime.c,v 1.3 1995/03/25 18:13:36 glass Exp $"; 123 #endif 124 125 /* Local functions */ 126 127 /* 128 * parse a token, checking if it's something special to us 129 */ 130 static int 131 parse_token(arg) 132 char *arg; 133 { 134 int i; 135 136 for (i=0; i<(sizeof Specials/sizeof Specials[0]); i++) 137 if (strcasecmp(Specials[i].name, arg) == 0) { 138 return sc_tokid = Specials[i].value; 139 } 140 141 /* not special - must be some random id */ 142 return ID; 143 } /* parse_token */ 144 145 146 /* 147 * init_scanner() sets up the scanner to eat arguments 148 */ 149 static void 150 init_scanner(argc, argv) 151 int argc; 152 char **argv; 153 { 154 scp = argv; 155 scc = argc; 156 need = 1; 157 sc_len = 1; 158 while (--argc > 0) 159 sc_len += strlen(*++argv); 160 161 sc_token = (char *) malloc(sc_len); 162 if (sc_token == NULL) 163 panic("Insufficient virtual memory"); 164 } /* init_scanner */ 165 166 /* 167 * token() fetches a token from the input stream 168 */ 169 static int 170 token() 171 { 172 int idx; 173 174 while (1) { 175 memset(sc_token, 0, sc_len); 176 sc_tokid = EOF; 177 idx = 0; 178 179 /* 180 * if we need to read another argument, walk along the argument list; 181 * when we fall off the arglist, we'll just return EOF forever 182 */ 183 if (need) { 184 if (scc < 1) 185 return sc_tokid; 186 sct = *scp; 187 scp++; 188 scc--; 189 need = 0; 190 } 191 /* 192 * eat whitespace now - if we walk off the end of the argument, 193 * we'll continue, which puts us up at the top of the while loop 194 * to fetch the next argument in 195 */ 196 while (isspace(*sct)) 197 ++sct; 198 if (!*sct) { 199 need = 1; 200 continue; 201 } 202 203 /* 204 * preserve the first character of the new token 205 */ 206 sc_token[0] = *sct++; 207 208 /* 209 * then see what it is 210 */ 211 if (isdigit(sc_token[0])) { 212 while (isdigit(*sct)) 213 sc_token[++idx] = *sct++; 214 sc_token[++idx] = 0; 215 return sc_tokid = NUMBER; 216 } else if (isalpha(sc_token[0])) { 217 while (isalpha(*sct)) 218 sc_token[++idx] = *sct++; 219 sc_token[++idx] = 0; 220 return parse_token(sc_token); 221 } 222 else if (sc_token[0] == ':' || sc_token[0] == '.') 223 return sc_tokid = DOT; 224 else if (sc_token[0] == '+') 225 return sc_tokid = PLUS; 226 else if (sc_token[0] == '/') 227 return sc_tokid = SLASH; 228 else 229 return sc_tokid = JUNK; 230 } /* while (1) */ 231 } /* token */ 232 233 234 /* 235 * plonk() gives an appropriate error message if a token is incorrect 236 */ 237 static void 238 plonk(tok) 239 int tok; 240 { 241 panic((tok == EOF) ? "incomplete time" 242 : "garbled time"); 243 } /* plonk */ 244 245 246 /* 247 * expect() gets a token and dies most horribly if it's not the token we want 248 */ 249 static void 250 expect(desired) 251 int desired; 252 { 253 if (token() != desired) 254 plonk(sc_tokid); /* and we die here... */ 255 } /* expect */ 256 257 258 /* 259 * dateadd() adds a number of minutes to a date. It is extraordinarily 260 * stupid regarding day-of-month overflow, and will most likely not 261 * work properly 262 */ 263 static void 264 dateadd(minutes, tm) 265 int minutes; 266 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(tm) 308 struct tm *tm; 309 { 310 int delay; 311 312 expect(NUMBER); 313 314 delay = atoi(sc_token); 315 316 switch (token()) { 317 case WEEKS: 318 delay *= 7; 319 case DAYS: 320 delay *= 24; 321 case HOURS: 322 delay *= 60; 323 case MINUTES: 324 dateadd(delay, tm); 325 return; 326 } 327 plonk(sc_tokid); 328 } /* plus */ 329 330 331 /* 332 * tod() computes the time of day 333 * [NUMBER [DOT NUMBER] [AM|PM]] 334 */ 335 static void 336 tod(tm) 337 struct tm *tm; 338 { 339 int hour, minute = 0; 340 int tlen; 341 342 hour = atoi(sc_token); 343 tlen = strlen(sc_token); 344 345 /* 346 * first pick out the time of day - if it's 4 digits, we assume 347 * a HHMM time, otherwise it's HH DOT MM time 348 */ 349 if (token() == DOT) { 350 expect(NUMBER); 351 minute = atoi(sc_token); 352 if (minute > 59) 353 panic("garbled time"); 354 token(); 355 } else if (tlen == 4) { 356 minute = hour%100; 357 if (minute > 59) 358 panic("garbeld time"); 359 hour = hour/100; 360 } 361 362 /* 363 * check if an AM or PM specifier was given 364 */ 365 if (sc_tokid == AM || sc_tokid == PM) { 366 if (hour > 12) 367 panic("garbled time"); 368 369 if (sc_tokid == PM) 370 hour += 12; 371 token(); 372 } else if (hour > 23) 373 panic("garbled time"); 374 375 /* 376 * if we specify an absolute time, we don't want to bump the day even 377 * if we've gone past that time - but if we're specifying a time plus 378 * a relative offset, it's okay to bump things 379 */ 380 if ((sc_tokid == EOF || sc_tokid == PLUS) && tm->tm_hour > hour) 381 tm->tm_mday++; 382 383 tm->tm_hour = hour; 384 tm->tm_min = minute; 385 if (tm->tm_hour == 24) { 386 tm->tm_hour = 0; 387 tm->tm_mday++; 388 } 389 } /* tod */ 390 391 392 /* 393 * assign_date() assigns a date, wrapping to next year if needed 394 */ 395 static void 396 assign_date(tm, mday, mon, year) 397 struct tm *tm; 398 long mday, mon, year; 399 { 400 if (year > 99) { 401 if (year > 1899) 402 year -= 1900; 403 else 404 panic("garbled time"); 405 } 406 407 if (year < 0 && 408 (tm->tm_mon > mon ||(tm->tm_mon == mon && tm->tm_mday > mday))) 409 year = tm->tm_year + 1; 410 411 tm->tm_mday = mday; 412 tm->tm_mon = mon; 413 414 if (year >= 0) 415 tm->tm_year = year; 416 } /* assign_date */ 417 418 419 /* 420 * month() picks apart a month specification 421 * 422 * /[<month> NUMBER [NUMBER]] \ 423 * |[TOMORROW] | 424 * |NUMBER [SLASH NUMBER [SLASH NUMBER]]| 425 * \PLUS NUMBER MINUTES|HOURS|DAYS|WEEKS/ 426 */ 427 static void 428 month(tm) 429 struct tm *tm; 430 { 431 long year= (-1); 432 long mday, mon; 433 int tlen; 434 435 switch (sc_tokid) { 436 case PLUS: 437 plus(tm); 438 break; 439 440 case TOMORROW: 441 /* do something tomorrow */ 442 tm->tm_mday ++; 443 case TODAY: /* force ourselves to stay in today - no further processing */ 444 token(); 445 break; 446 447 case JAN: case FEB: case MAR: case APR: case MAY: case JUN: 448 case JUL: case AUG: case SEP: case OCT: case NOV: case DEC: 449 /* 450 * do month mday [year] 451 */ 452 mon = (sc_tokid-JAN); 453 expect(NUMBER); 454 mday = atol(sc_token); 455 if (token() == NUMBER) { 456 year = atol(sc_token); 457 token(); 458 } 459 assign_date(tm, mday, mon, year); 460 break; 461 462 case NUMBER: 463 /* 464 * get numeric MMDDYY, mm/dd/yy, or dd.mm.yy 465 */ 466 tlen = strlen(sc_token); 467 mon = atol(sc_token); 468 token(); 469 470 if (sc_tokid == SLASH || sc_tokid == DOT) { 471 int sep; 472 473 sep = sc_tokid; 474 expect(NUMBER); 475 mday = atol(sc_token); 476 if (token() == sep) { 477 expect(NUMBER); 478 year = atol(sc_token); 479 token(); 480 } 481 482 /* 483 * flip months and days for european timing 484 */ 485 if (sep == DOT) { 486 int x = mday; 487 mday = mon; 488 mon = x; 489 } 490 } else if (tlen == 6 || tlen == 8) { 491 if (tlen == 8) { 492 year = (mon % 10000) - 1900; 493 mon /= 10000; 494 } else { 495 year = mon % 100; 496 mon /= 100; 497 } 498 mday = mon % 100; 499 mon /= 100; 500 } else 501 panic("garbled time"); 502 503 mon--; 504 if (mon < 0 || mon > 11 || mday < 1 || mday > 31) 505 panic("garbled time"); 506 507 assign_date(tm, mday, mon, year); 508 break; 509 } /* case */ 510 } /* month */ 511 512 513 /* Global functions */ 514 515 time_t 516 parsetime(argc, argv) 517 int argc; 518 char **argv; 519 { 520 /* 521 * Do the argument parsing, die if necessary, and return the time the job 522 * should be run. 523 */ 524 time_t nowtimer, runtimer; 525 struct tm nowtime, runtime; 526 int hr = 0; 527 /* this MUST be initialized to zero for midnight/noon/teatime */ 528 529 nowtimer = time(NULL); 530 nowtime = *localtime(&nowtimer); 531 532 runtime = nowtime; 533 runtime.tm_sec = 0; 534 runtime.tm_isdst = 0; 535 536 if (argc <= optind) 537 usage(); 538 539 init_scanner(argc-optind, argv+optind); 540 541 switch (token()) { 542 case NOW: /* now is optional prefix for PLUS tree */ 543 expect(PLUS); 544 case PLUS: 545 plus(&runtime); 546 break; 547 548 case NUMBER: 549 tod(&runtime); 550 month(&runtime); 551 break; 552 553 /* 554 * evil coding for TEATIME|NOON|MIDNIGHT - we've initialised 555 * hr to zero up above, then fall into this case in such a 556 * way so we add +12 +4 hours to it for teatime, +12 hours 557 * to it for noon, and nothing at all for midnight, then 558 * set our runtime to that hour before leaping into the 559 * month scanner 560 */ 561 case TEATIME: 562 hr += 4; 563 case NOON: 564 hr += 12; 565 case MIDNIGHT: 566 if (runtime.tm_hour >= hr) 567 runtime.tm_mday++; 568 runtime.tm_hour = hr; 569 runtime.tm_min = 0; 570 token(); 571 /* fall through to month setting */ 572 default: 573 month(&runtime); 574 break; 575 } /* ugly case statement */ 576 expect(EOF); 577 578 /* 579 * adjust for daylight savings time 580 */ 581 runtime.tm_isdst = -1; 582 runtimer = mktime(&runtime); 583 if (runtime.tm_isdst > 0) { 584 runtimer -= 3600; 585 runtimer = mktime(&runtime); 586 } 587 588 if (runtimer < 0) 589 panic("garbled time"); 590 591 if (nowtimer > runtimer) 592 panic("Trying to travel back in time"); 593 594 return runtimer; 595 } /* parsetime */ 596