parsetime.c revision 1.6
1 /* $NetBSD: parsetime.c,v 1.6 1998/02/04 15:16:29 christos 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 <tzfile.h> 47 #include <unistd.h> 48 #include <ctype.h> 49 50 /* Local headers */ 51 52 #include "at.h" 53 #include "panic.h" 54 #include "parsetime.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 }; 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 } Specials[] = { 75 { "midnight", MIDNIGHT }, /* 00:00:00 of today or tomorrow */ 76 { "noon", NOON }, /* 12:00:00 of today or tomorrow */ 77 { "teatime", TEATIME }, /* 16:00:00 of today or tomorrow */ 78 { "am", AM }, /* morning times for 0-12 clock */ 79 { "pm", PM }, /* evening times for 0-12 clock */ 80 { "tomorrow", TOMORROW }, /* execute 24 hours from time */ 81 { "today", TODAY }, /* execute today - don't advance time */ 82 { "now", NOW }, /* opt prefix for PLUS */ 83 84 { "minute", MINUTES }, /* minutes multiplier */ 85 { "min", MINUTES }, 86 { "m", MINUTES }, 87 { "minutes", MINUTES }, /* (pluralized) */ 88 { "hour", HOURS }, /* hours ... */ 89 { "hr", HOURS }, /* abbreviated */ 90 { "h", HOURS }, 91 { "hours", HOURS }, /* (pluralized) */ 92 { "day", DAYS }, /* days ... */ 93 { "d", DAYS }, 94 { "days", DAYS }, /* (pluralized) */ 95 { "week", WEEKS }, /* week ... */ 96 { "w", WEEKS }, 97 { "weeks", WEEKS }, /* (pluralized) */ 98 { "jan", JAN }, 99 { "feb", FEB }, 100 { "mar", MAR }, 101 { "apr", APR }, 102 { "may", MAY }, 103 { "jun", JUN }, 104 { "jul", JUL }, 105 { "aug", AUG }, 106 { "sep", SEP }, 107 { "oct", OCT }, 108 { "nov", NOV }, 109 { "dec", DEC } 110 } ; 111 112 /* File scope variables */ 113 114 static char **scp; /* scanner - pointer at arglist */ 115 static char scc; /* scanner - count of remaining arguments */ 116 static char *sct; /* scanner - next char pointer in current argument */ 117 static int need; /* scanner - need to advance to next argument */ 118 119 static char *sc_token; /* scanner - token buffer */ 120 static size_t sc_len; /* scanner - lenght of token buffer */ 121 static int sc_tokid; /* scanner - token id */ 122 123 #ifndef lint 124 __RCSID("$NetBSD: parsetime.c,v 1.6 1998/02/04 15:16:29 christos Exp $"); 125 #endif 126 127 /* Local functions */ 128 129 static void assign_date __P((struct tm *, long, long, long)); 130 static void dateadd __P((int, struct tm *)); 131 static void expect __P((int)); 132 static void init_scanner __P((int, char **)); 133 static void month __P((struct tm *)); 134 static int parse_token __P((char *)); 135 static void plonk __P((int)); 136 static void plus __P((struct tm *)); 137 static void tod __P((struct tm *)); 138 static int token __P((void)); 139 140 /* 141 * parse a token, checking if it's something special to us 142 */ 143 static int 144 parse_token(arg) 145 char *arg; 146 { 147 int i; 148 149 for (i=0; i<(sizeof Specials/sizeof Specials[0]); i++) 150 if (strcasecmp(Specials[i].name, arg) == 0) { 151 return sc_tokid = Specials[i].value; 152 } 153 154 /* not special - must be some random id */ 155 return ID; 156 } /* parse_token */ 157 158 159 /* 160 * init_scanner() sets up the scanner to eat arguments 161 */ 162 static void 163 init_scanner(argc, argv) 164 int argc; 165 char **argv; 166 { 167 scp = argv; 168 scc = argc; 169 need = 1; 170 sc_len = 1; 171 while (--argc > 0) 172 sc_len += strlen(*++argv); 173 174 sc_token = (char *) malloc(sc_len); 175 if (sc_token == NULL) 176 panic("Insufficient virtual memory"); 177 } /* init_scanner */ 178 179 /* 180 * token() fetches a token from the input stream 181 */ 182 static int 183 token() 184 { 185 int idx; 186 187 while (1) { 188 memset(sc_token, 0, sc_len); 189 sc_tokid = EOF; 190 idx = 0; 191 192 /* 193 * if we need to read another argument, walk along the argument list; 194 * when we fall off the arglist, we'll just return EOF forever 195 */ 196 if (need) { 197 if (scc < 1) 198 return sc_tokid; 199 sct = *scp; 200 scp++; 201 scc--; 202 need = 0; 203 } 204 /* 205 * eat whitespace now - if we walk off the end of the argument, 206 * we'll continue, which puts us up at the top of the while loop 207 * to fetch the next argument in 208 */ 209 while (isspace(*sct)) 210 ++sct; 211 if (!*sct) { 212 need = 1; 213 continue; 214 } 215 216 /* 217 * preserve the first character of the new token 218 */ 219 sc_token[0] = *sct++; 220 221 /* 222 * then see what it is 223 */ 224 if (isdigit(sc_token[0])) { 225 while (isdigit(*sct)) 226 sc_token[++idx] = *sct++; 227 sc_token[++idx] = 0; 228 return sc_tokid = NUMBER; 229 } else if (isalpha(sc_token[0])) { 230 while (isalpha(*sct)) 231 sc_token[++idx] = *sct++; 232 sc_token[++idx] = 0; 233 return parse_token(sc_token); 234 } 235 else if (sc_token[0] == ':' || sc_token[0] == '.') 236 return sc_tokid = DOT; 237 else if (sc_token[0] == '+') 238 return sc_tokid = PLUS; 239 else if (sc_token[0] == '/') 240 return sc_tokid = SLASH; 241 else 242 return sc_tokid = JUNK; 243 } /* while (1) */ 244 } /* token */ 245 246 247 /* 248 * plonk() gives an appropriate error message if a token is incorrect 249 */ 250 static void 251 plonk(tok) 252 int tok; 253 { 254 panic((tok == EOF) ? "incomplete time" 255 : "garbled time"); 256 } /* plonk */ 257 258 259 /* 260 * expect() gets a token and dies most horribly if it's not the token we want 261 */ 262 static void 263 expect(desired) 264 int desired; 265 { 266 if (token() != desired) 267 plonk(sc_tokid); /* and we die here... */ 268 } /* expect */ 269 270 271 /* 272 * dateadd() adds a number of minutes to a date. It is extraordinarily 273 * stupid regarding day-of-month overflow, and will most likely not 274 * work properly 275 */ 276 static void 277 dateadd(minutes, tm) 278 int minutes; 279 struct tm *tm; 280 { 281 /* increment days */ 282 283 while (minutes > 24*60) { 284 minutes -= 24*60; 285 tm->tm_mday++; 286 } 287 288 /* increment hours */ 289 while (minutes > 60) { 290 minutes -= 60; 291 tm->tm_hour++; 292 if (tm->tm_hour > 23) { 293 tm->tm_mday++; 294 tm->tm_hour = 0; 295 } 296 } 297 298 /* increment minutes */ 299 tm->tm_min += minutes; 300 301 if (tm->tm_min > 59) { 302 tm->tm_hour++; 303 tm->tm_min -= 60; 304 305 if (tm->tm_hour > 23) { 306 tm->tm_mday++; 307 tm->tm_hour = 0; 308 } 309 } 310 } /* dateadd */ 311 312 313 /* 314 * plus() parses a now + time 315 * 316 * at [NOW] PLUS NUMBER [MINUTES|HOURS|DAYS|WEEKS] 317 * 318 */ 319 static void 320 plus(tm) 321 struct tm *tm; 322 { 323 int delay; 324 325 expect(NUMBER); 326 327 delay = atoi(sc_token); 328 329 switch (token()) { 330 case WEEKS: 331 delay *= 7; 332 case DAYS: 333 delay *= 24; 334 case HOURS: 335 delay *= 60; 336 case MINUTES: 337 dateadd(delay, tm); 338 return; 339 } 340 plonk(sc_tokid); 341 } /* plus */ 342 343 344 /* 345 * tod() computes the time of day 346 * [NUMBER [DOT NUMBER] [AM|PM]] 347 */ 348 static void 349 tod(tm) 350 struct tm *tm; 351 { 352 int hour, minute = 0; 353 int tlen; 354 355 hour = atoi(sc_token); 356 tlen = strlen(sc_token); 357 358 /* 359 * first pick out the time of day - if it's 4 digits, we assume 360 * a HHMM time, otherwise it's HH DOT MM time 361 */ 362 if (token() == DOT) { 363 expect(NUMBER); 364 minute = atoi(sc_token); 365 token(); 366 } else if (tlen == 4) { 367 minute = hour%100; 368 hour = hour/100; 369 } 370 371 if (minute > 59) 372 panic("garbled time"); 373 374 /* 375 * check if an AM or PM specifier was given 376 */ 377 if (sc_tokid == AM || sc_tokid == PM) { 378 if (hour > 12) 379 panic("garbled time"); 380 else if (hour == 12) 381 hour = 0; 382 383 if (sc_tokid == PM) 384 hour += 12; 385 token(); 386 } else if (hour > 23) 387 panic("garbled time"); 388 389 /* 390 * if we specify an absolute time, we don't want to bump the day even 391 * if we've gone past that time - but if we're specifying a time plus 392 * a relative offset, it's okay to bump things 393 */ 394 if ((sc_tokid == EOF || sc_tokid == PLUS) && tm->tm_hour > hour) 395 tm->tm_mday++; 396 397 tm->tm_hour = hour; 398 tm->tm_min = minute; 399 } /* tod */ 400 401 402 /* 403 * assign_date() assigns a date, wrapping to next year if needed 404 */ 405 static void 406 assign_date(tm, mday, mon, year) 407 struct tm *tm; 408 long mday, mon, year; 409 { 410 if (year > 99) { 411 if (year >= TM_YEAR_BASE) 412 year -= TM_YEAR_BASE; 413 else 414 panic("garbled time"); 415 } 416 417 if (year >= 0) { 418 if (year < 69) 419 tm->tm_year = year + 2000 - TM_YEAR_BASE; 420 else 421 tm->tm_year = year + 1900 - TM_YEAR_BASE; 422 } 423 else { /* year < 0 */ 424 if (tm->tm_mon > mon || (tm->tm_mon == mon && tm->tm_mday > mday)) 425 tm->tm_year++; 426 } 427 428 tm->tm_mday = mday; 429 tm->tm_mon = mon; 430 } /* assign_date */ 431 432 433 /* 434 * month() picks apart a month specification 435 * 436 * /[<month> NUMBER [NUMBER]] \ 437 * |[TOMORROW] | 438 * |NUMBER [SLASH NUMBER [SLASH NUMBER]]| 439 * \PLUS NUMBER MINUTES|HOURS|DAYS|WEEKS/ 440 */ 441 static void 442 month(tm) 443 struct tm *tm; 444 { 445 long year= (-1); 446 long mday, mon; 447 int tlen; 448 449 mday = 0; 450 switch (sc_tokid) { 451 case PLUS: 452 plus(tm); 453 break; 454 455 case TOMORROW: 456 /* do something tomorrow */ 457 tm->tm_mday ++; 458 case TODAY: /* force ourselves to stay in today - no further processing */ 459 token(); 460 break; 461 462 case JAN: case FEB: case MAR: case APR: case MAY: case JUN: 463 case JUL: case AUG: case SEP: case OCT: case NOV: case DEC: 464 /* 465 * do month mday [year] 466 */ 467 mon = (sc_tokid-JAN); 468 expect(NUMBER); 469 mday = atol(sc_token); 470 if (token() == NUMBER) { 471 year = atol(sc_token); 472 token(); 473 } 474 assign_date(tm, mday, mon, year); 475 break; 476 477 case NUMBER: 478 /* 479 * get numeric MMDDYY, mm/dd/yy, or dd.mm.yy 480 */ 481 tlen = strlen(sc_token); 482 mon = atol(sc_token); 483 token(); 484 485 if (sc_tokid == SLASH || sc_tokid == DOT) { 486 int sep; 487 488 sep = sc_tokid; 489 expect(NUMBER); 490 mday = atol(sc_token); 491 if (token() == sep) { 492 expect(NUMBER); 493 year = atol(sc_token); 494 token(); 495 } 496 497 /* 498 * flip months and days for european timing 499 */ 500 if (sep == DOT) { 501 int x = mday; 502 mday = mon; 503 mon = x; 504 } 505 } else if (tlen == 6 || tlen == 8) { 506 if (tlen == 8) { 507 year = (mon % 10000) - 1900; 508 mon /= 10000; 509 } else { 510 year = mon % 100; 511 mon /= 100; 512 } 513 mday = mon % 100; 514 mon /= 100; 515 } else 516 panic("garbled time"); 517 518 mon--; 519 if (mon < 0 || mon > 11 || mday < 1 || mday > 31) 520 panic("garbled time"); 521 522 assign_date(tm, mday, mon, year); 523 break; 524 } /* case */ 525 } /* month */ 526 527 528 /* Global functions */ 529 530 time_t 531 parsetime(argc, argv) 532 int argc; 533 char **argv; 534 { 535 /* 536 * Do the argument parsing, die if necessary, and return the time the job 537 * should be run. 538 */ 539 time_t nowtimer, runtimer; 540 struct tm nowtime, runtime; 541 int hr = 0; 542 /* this MUST be initialized to zero for midnight/noon/teatime */ 543 544 nowtimer = time(NULL); 545 nowtime = *localtime(&nowtimer); 546 547 runtime = nowtime; 548 runtime.tm_sec = 0; 549 runtime.tm_isdst = 0; 550 551 if (argc <= optind) 552 usage(); 553 554 init_scanner(argc-optind, argv+optind); 555 556 switch (token()) { 557 case NOW: /* now is optional prefix for PLUS tree */ 558 expect(PLUS); 559 case PLUS: 560 plus(&runtime); 561 break; 562 563 case NUMBER: 564 tod(&runtime); 565 month(&runtime); 566 break; 567 568 /* 569 * evil coding for TEATIME|NOON|MIDNIGHT - we've initialised 570 * hr to zero up above, then fall into this case in such a 571 * way so we add +12 +4 hours to it for teatime, +12 hours 572 * to it for noon, and nothing at all for midnight, then 573 * set our runtime to that hour before leaping into the 574 * month scanner 575 */ 576 case TEATIME: 577 hr += 4; 578 case NOON: 579 hr += 12; 580 case MIDNIGHT: 581 if (runtime.tm_hour >= hr) 582 runtime.tm_mday++; 583 runtime.tm_hour = hr; 584 runtime.tm_min = 0; 585 token(); 586 /* fall through to month setting */ 587 default: 588 month(&runtime); 589 break; 590 } /* ugly case statement */ 591 expect(EOF); 592 593 /* 594 * adjust for daylight savings time 595 */ 596 runtime.tm_isdst = -1; 597 runtimer = mktime(&runtime); 598 if (runtime.tm_isdst > 0) { 599 runtimer -= 3600; 600 runtimer = mktime(&runtime); 601 } 602 603 if (runtimer < 0) 604 panic("garbled time"); 605 606 if (nowtimer > runtimer) 607 panic("Trying to travel back in time"); 608 609 return runtimer; 610 } /* parsetime */ 611
Indexes created Mon Oct 20 11:09:49 GMT 2025