parsetime.c revision 1.5
1 /* $NetBSD: parsetime.c,v 1.5 1997/10/18 12:04:18 lukem 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 #include "parsetime.h" 54 55 56 /* Structures and unions */ 57 58 enum { /* symbols */ 59 MIDNIGHT, NOON, TEATIME, 60 PM, AM, TOMORROW, TODAY, NOW, 61 MINUTES, HOURS, DAYS, WEEKS, 62 NUMBER, PLUS, DOT, SLASH, ID, JUNK, 63 JAN, FEB, MAR, APR, MAY, JUN, 64 JUL, AUG, SEP, OCT, NOV, DEC 65 }; 66 67 /* 68 * parse translation table - table driven parsers can be your FRIEND! 69 */ 70 struct { 71 char *name; /* token name */ 72 int value; /* token id */ 73 } Specials[] = { 74 { "midnight", MIDNIGHT }, /* 00:00:00 of today or tomorrow */ 75 { "noon", NOON }, /* 12:00:00 of today or tomorrow */ 76 { "teatime", TEATIME }, /* 16:00:00 of today or tomorrow */ 77 { "am", AM }, /* morning times for 0-12 clock */ 78 { "pm", PM }, /* evening times for 0-12 clock */ 79 { "tomorrow", TOMORROW }, /* execute 24 hours from time */ 80 { "today", TODAY }, /* execute today - don't advance time */ 81 { "now", NOW }, /* opt prefix for PLUS */ 82 83 { "minute", MINUTES }, /* minutes multiplier */ 84 { "min", MINUTES }, 85 { "m", MINUTES }, 86 { "minutes", MINUTES }, /* (pluralized) */ 87 { "hour", HOURS }, /* hours ... */ 88 { "hr", HOURS }, /* abbreviated */ 89 { "h", HOURS }, 90 { "hours", HOURS }, /* (pluralized) */ 91 { "day", DAYS }, /* days ... */ 92 { "d", DAYS }, 93 { "days", DAYS }, /* (pluralized) */ 94 { "week", WEEKS }, /* week ... */ 95 { "w", WEEKS }, 96 { "weeks", WEEKS }, /* (pluralized) */ 97 { "jan", JAN }, 98 { "feb", FEB }, 99 { "mar", MAR }, 100 { "apr", APR }, 101 { "may", MAY }, 102 { "jun", JUN }, 103 { "jul", JUL }, 104 { "aug", AUG }, 105 { "sep", SEP }, 106 { "oct", OCT }, 107 { "nov", NOV }, 108 { "dec", DEC } 109 } ; 110 111 /* File scope variables */ 112 113 static char **scp; /* scanner - pointer at arglist */ 114 static char scc; /* scanner - count of remaining arguments */ 115 static char *sct; /* scanner - next char pointer in current argument */ 116 static int need; /* scanner - need to advance to next argument */ 117 118 static char *sc_token; /* scanner - token buffer */ 119 static size_t sc_len; /* scanner - lenght of token buffer */ 120 static int sc_tokid; /* scanner - token id */ 121 122 #ifndef lint 123 __RCSID("$NetBSD: parsetime.c,v 1.5 1997/10/18 12:04:18 lukem Exp $"); 124 #endif 125 126 /* Local functions */ 127 128 static void assign_date __P((struct tm *, long, long, long)); 129 static void dateadd __P((int, struct tm *)); 130 static void expect __P((int)); 131 static void init_scanner __P((int, char **)); 132 static void month __P((struct tm *)); 133 static int parse_token __P((char *)); 134 static void plonk __P((int)); 135 static void plus __P((struct tm *)); 136 static void tod __P((struct tm *)); 137 static int token __P((void)); 138 139 /* 140 * parse a token, checking if it's something special to us 141 */ 142 static int 143 parse_token(arg) 144 char *arg; 145 { 146 int i; 147 148 for (i=0; i<(sizeof Specials/sizeof Specials[0]); i++) 149 if (strcasecmp(Specials[i].name, arg) == 0) { 150 return sc_tokid = Specials[i].value; 151 } 152 153 /* not special - must be some random id */ 154 return ID; 155 } /* parse_token */ 156 157 158 /* 159 * init_scanner() sets up the scanner to eat arguments 160 */ 161 static void 162 init_scanner(argc, argv) 163 int argc; 164 char **argv; 165 { 166 scp = argv; 167 scc = argc; 168 need = 1; 169 sc_len = 1; 170 while (--argc > 0) 171 sc_len += strlen(*++argv); 172 173 sc_token = (char *) malloc(sc_len); 174 if (sc_token == NULL) 175 panic("Insufficient virtual memory"); 176 } /* init_scanner */ 177 178 /* 179 * token() fetches a token from the input stream 180 */ 181 static int 182 token() 183 { 184 int idx; 185 186 while (1) { 187 memset(sc_token, 0, sc_len); 188 sc_tokid = EOF; 189 idx = 0; 190 191 /* 192 * if we need to read another argument, walk along the argument list; 193 * when we fall off the arglist, we'll just return EOF forever 194 */ 195 if (need) { 196 if (scc < 1) 197 return sc_tokid; 198 sct = *scp; 199 scp++; 200 scc--; 201 need = 0; 202 } 203 /* 204 * eat whitespace now - if we walk off the end of the argument, 205 * we'll continue, which puts us up at the top of the while loop 206 * to fetch the next argument in 207 */ 208 while (isspace(*sct)) 209 ++sct; 210 if (!*sct) { 211 need = 1; 212 continue; 213 } 214 215 /* 216 * preserve the first character of the new token 217 */ 218 sc_token[0] = *sct++; 219 220 /* 221 * then see what it is 222 */ 223 if (isdigit(sc_token[0])) { 224 while (isdigit(*sct)) 225 sc_token[++idx] = *sct++; 226 sc_token[++idx] = 0; 227 return sc_tokid = NUMBER; 228 } else if (isalpha(sc_token[0])) { 229 while (isalpha(*sct)) 230 sc_token[++idx] = *sct++; 231 sc_token[++idx] = 0; 232 return parse_token(sc_token); 233 } 234 else if (sc_token[0] == ':' || sc_token[0] == '.') 235 return sc_tokid = DOT; 236 else if (sc_token[0] == '+') 237 return sc_tokid = PLUS; 238 else if (sc_token[0] == '/') 239 return sc_tokid = SLASH; 240 else 241 return sc_tokid = JUNK; 242 } /* while (1) */ 243 } /* token */ 244 245 246 /* 247 * plonk() gives an appropriate error message if a token is incorrect 248 */ 249 static void 250 plonk(tok) 251 int tok; 252 { 253 panic((tok == EOF) ? "incomplete time" 254 : "garbled time"); 255 } /* plonk */ 256 257 258 /* 259 * expect() gets a token and dies most horribly if it's not the token we want 260 */ 261 static void 262 expect(desired) 263 int desired; 264 { 265 if (token() != desired) 266 plonk(sc_tokid); /* and we die here... */ 267 } /* expect */ 268 269 270 /* 271 * dateadd() adds a number of minutes to a date. It is extraordinarily 272 * stupid regarding day-of-month overflow, and will most likely not 273 * work properly 274 */ 275 static void 276 dateadd(minutes, tm) 277 int minutes; 278 struct tm *tm; 279 { 280 /* increment days */ 281 282 while (minutes > 24*60) { 283 minutes -= 24*60; 284 tm->tm_mday++; 285 } 286 287 /* increment hours */ 288 while (minutes > 60) { 289 minutes -= 60; 290 tm->tm_hour++; 291 if (tm->tm_hour > 23) { 292 tm->tm_mday++; 293 tm->tm_hour = 0; 294 } 295 } 296 297 /* increment minutes */ 298 tm->tm_min += minutes; 299 300 if (tm->tm_min > 59) { 301 tm->tm_hour++; 302 tm->tm_min -= 60; 303 304 if (tm->tm_hour > 23) { 305 tm->tm_mday++; 306 tm->tm_hour = 0; 307 } 308 } 309 } /* dateadd */ 310 311 312 /* 313 * plus() parses a now + time 314 * 315 * at [NOW] PLUS NUMBER [MINUTES|HOURS|DAYS|WEEKS] 316 * 317 */ 318 static void 319 plus(tm) 320 struct tm *tm; 321 { 322 int delay; 323 324 expect(NUMBER); 325 326 delay = atoi(sc_token); 327 328 switch (token()) { 329 case WEEKS: 330 delay *= 7; 331 case DAYS: 332 delay *= 24; 333 case HOURS: 334 delay *= 60; 335 case MINUTES: 336 dateadd(delay, tm); 337 return; 338 } 339 plonk(sc_tokid); 340 } /* plus */ 341 342 343 /* 344 * tod() computes the time of day 345 * [NUMBER [DOT NUMBER] [AM|PM]] 346 */ 347 static void 348 tod(tm) 349 struct tm *tm; 350 { 351 int hour, minute = 0; 352 int tlen; 353 354 hour = atoi(sc_token); 355 tlen = strlen(sc_token); 356 357 /* 358 * first pick out the time of day - if it's 4 digits, we assume 359 * a HHMM time, otherwise it's HH DOT MM time 360 */ 361 if (token() == DOT) { 362 expect(NUMBER); 363 minute = atoi(sc_token); 364 token(); 365 } else if (tlen == 4) { 366 minute = hour%100; 367 hour = hour/100; 368 } 369 370 if (minute > 59) 371 panic("garbled time"); 372 373 /* 374 * check if an AM or PM specifier was given 375 */ 376 if (sc_tokid == AM || sc_tokid == PM) { 377 if (hour > 12) 378 panic("garbled time"); 379 else if (hour == 12) 380 hour = 0; 381 382 if (sc_tokid == PM) 383 hour += 12; 384 token(); 385 } else if (hour > 23) 386 panic("garbled time"); 387 388 /* 389 * if we specify an absolute time, we don't want to bump the day even 390 * if we've gone past that time - but if we're specifying a time plus 391 * a relative offset, it's okay to bump things 392 */ 393 if ((sc_tokid == EOF || sc_tokid == PLUS) && tm->tm_hour > hour) 394 tm->tm_mday++; 395 396 tm->tm_hour = hour; 397 tm->tm_min = minute; 398 } /* tod */ 399 400 401 /* 402 * assign_date() assigns a date, wrapping to next year if needed 403 */ 404 static void 405 assign_date(tm, mday, mon, year) 406 struct tm *tm; 407 long mday, mon, year; 408 { 409 if (year > 99) { 410 if (year > 1899) 411 year -= 1900; 412 else 413 panic("garbled time"); 414 } 415 416 if (year < 0 && 417 (tm->tm_mon > mon ||(tm->tm_mon == mon && tm->tm_mday > mday))) 418 year = tm->tm_year + 1; 419 420 tm->tm_mday = mday; 421 tm->tm_mon = mon; 422 423 if (year >= 0) 424 tm->tm_year = year; 425 } /* assign_date */ 426 427 428 /* 429 * month() picks apart a month specification 430 * 431 * /[<month> NUMBER [NUMBER]] \ 432 * |[TOMORROW] | 433 * |NUMBER [SLASH NUMBER [SLASH NUMBER]]| 434 * \PLUS NUMBER MINUTES|HOURS|DAYS|WEEKS/ 435 */ 436 static void 437 month(tm) 438 struct tm *tm; 439 { 440 long year= (-1); 441 long mday, mon; 442 int tlen; 443 444 mday = 0; 445 switch (sc_tokid) { 446 case PLUS: 447 plus(tm); 448 break; 449 450 case TOMORROW: 451 /* do something tomorrow */ 452 tm->tm_mday ++; 453 case TODAY: /* force ourselves to stay in today - no further processing */ 454 token(); 455 break; 456 457 case JAN: case FEB: case MAR: case APR: case MAY: case JUN: 458 case JUL: case AUG: case SEP: case OCT: case NOV: case DEC: 459 /* 460 * do month mday [year] 461 */ 462 mon = (sc_tokid-JAN); 463 expect(NUMBER); 464 mday = atol(sc_token); 465 if (token() == NUMBER) { 466 year = atol(sc_token); 467 token(); 468 } 469 assign_date(tm, mday, mon, year); 470 break; 471 472 case NUMBER: 473 /* 474 * get numeric MMDDYY, mm/dd/yy, or dd.mm.yy 475 */ 476 tlen = strlen(sc_token); 477 mon = atol(sc_token); 478 token(); 479 480 if (sc_tokid == SLASH || sc_tokid == DOT) { 481 int sep; 482 483 sep = sc_tokid; 484 expect(NUMBER); 485 mday = atol(sc_token); 486 if (token() == sep) { 487 expect(NUMBER); 488 year = atol(sc_token); 489 token(); 490 } 491 492 /* 493 * flip months and days for european timing 494 */ 495 if (sep == DOT) { 496 int x = mday; 497 mday = mon; 498 mon = x; 499 } 500 } else if (tlen == 6 || tlen == 8) { 501 if (tlen == 8) { 502 year = (mon % 10000) - 1900; 503 mon /= 10000; 504 } else { 505 year = mon % 100; 506 mon /= 100; 507 } 508 mday = mon % 100; 509 mon /= 100; 510 } else 511 panic("garbled time"); 512 513 mon--; 514 if (mon < 0 || mon > 11 || mday < 1 || mday > 31) 515 panic("garbled time"); 516 517 assign_date(tm, mday, mon, year); 518 break; 519 } /* case */ 520 } /* month */ 521 522 523 /* Global functions */ 524 525 time_t 526 parsetime(argc, argv) 527 int argc; 528 char **argv; 529 { 530 /* 531 * Do the argument parsing, die if necessary, and return the time the job 532 * should be run. 533 */ 534 time_t nowtimer, runtimer; 535 struct tm nowtime, runtime; 536 int hr = 0; 537 /* this MUST be initialized to zero for midnight/noon/teatime */ 538 539 nowtimer = time(NULL); 540 nowtime = *localtime(&nowtimer); 541 542 runtime = nowtime; 543 runtime.tm_sec = 0; 544 runtime.tm_isdst = 0; 545 546 if (argc <= optind) 547 usage(); 548 549 init_scanner(argc-optind, argv+optind); 550 551 switch (token()) { 552 case NOW: /* now is optional prefix for PLUS tree */ 553 expect(PLUS); 554 case PLUS: 555 plus(&runtime); 556 break; 557 558 case NUMBER: 559 tod(&runtime); 560 month(&runtime); 561 break; 562 563 /* 564 * evil coding for TEATIME|NOON|MIDNIGHT - we've initialised 565 * hr to zero up above, then fall into this case in such a 566 * way so we add +12 +4 hours to it for teatime, +12 hours 567 * to it for noon, and nothing at all for midnight, then 568 * set our runtime to that hour before leaping into the 569 * month scanner 570 */ 571 case TEATIME: 572 hr += 4; 573 case NOON: 574 hr += 12; 575 case MIDNIGHT: 576 if (runtime.tm_hour >= hr) 577 runtime.tm_mday++; 578 runtime.tm_hour = hr; 579 runtime.tm_min = 0; 580 token(); 581 /* fall through to month setting */ 582 default: 583 month(&runtime); 584 break; 585 } /* ugly case statement */ 586 expect(EOF); 587 588 /* 589 * adjust for daylight savings time 590 */ 591 runtime.tm_isdst = -1; 592 runtimer = mktime(&runtime); 593 if (runtime.tm_isdst > 0) { 594 runtimer -= 3600; 595 runtimer = mktime(&runtime); 596 } 597 598 if (runtimer < 0) 599 panic("garbled time"); 600 601 if (nowtimer > runtimer) 602 panic("Trying to travel back in time"); 603 604 return runtimer; 605 } /* parsetime */ 606
Indexes created Wed Sep 24 05:09:52 GMT 2025