parsetime.c revision 1.4
1 /* $NetBSD: parsetime.c,v 1.4 1997/07/18 01:09:48 phil 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 1.4 1997/07/18 01:09:48 phil 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 token(); 353 } else if (tlen == 4) { 354 minute = hour%100; 355 hour = hour/100; 356 } 357 358 if (minute > 59) 359 panic("garbled time"); 360 361 /* 362 * check if an AM or PM specifier was given 363 */ 364 if (sc_tokid == AM || sc_tokid == PM) { 365 if (hour > 12) 366 panic("garbled time"); 367 else if (hour == 12) 368 hour = 0; 369 370 if (sc_tokid == PM) 371 hour += 12; 372 token(); 373 } else if (hour > 23) 374 panic("garbled time"); 375 376 /* 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++; 383 384 tm->tm_hour = hour; 385 tm->tm_min = minute; 386 } /* tod */ 387 388 389 /* 390 * assign_date() assigns a date, wrapping to next year if needed 391 */ 392 static void 393 assign_date(tm, mday, mon, year) 394 struct tm *tm; 395 long mday, mon, year; 396 { 397 if (year > 99) { 398 if (year > 1899) 399 year -= 1900; 400 else 401 panic("garbled time"); 402 } 403 404 if (year < 0 && 405 (tm->tm_mon > mon ||(tm->tm_mon == mon && tm->tm_mday > mday))) 406 year = tm->tm_year + 1; 407 408 tm->tm_mday = mday; 409 tm->tm_mon = mon; 410 411 if (year >= 0) 412 tm->tm_year = year; 413 } /* assign_date */ 414 415 416 /* 417 * month() picks apart a month specification 418 * 419 * /[<month> NUMBER [NUMBER]] \ 420 * |[TOMORROW] | 421 * |NUMBER [SLASH NUMBER [SLASH NUMBER]]| 422 * \PLUS NUMBER MINUTES|HOURS|DAYS|WEEKS/ 423 */ 424 static void 425 month(tm) 426 struct tm *tm; 427 { 428 long year= (-1); 429 long mday, mon; 430 int tlen; 431 432 switch (sc_tokid) { 433 case PLUS: 434 plus(tm); 435 break; 436 437 case TOMORROW: 438 /* do something tomorrow */ 439 tm->tm_mday ++; 440 case TODAY: /* force ourselves to stay in today - no further processing */ 441 token(); 442 break; 443 444 case JAN: case FEB: case MAR: case APR: case MAY: case JUN: 445 case JUL: case AUG: case SEP: case OCT: case NOV: case DEC: 446 /* 447 * do month mday [year] 448 */ 449 mon = (sc_tokid-JAN); 450 expect(NUMBER); 451 mday = atol(sc_token); 452 if (token() == NUMBER) { 453 year = atol(sc_token); 454 token(); 455 } 456 assign_date(tm, mday, mon, year); 457 break; 458 459 case NUMBER: 460 /* 461 * get numeric MMDDYY, mm/dd/yy, or dd.mm.yy 462 */ 463 tlen = strlen(sc_token); 464 mon = atol(sc_token); 465 token(); 466 467 if (sc_tokid == SLASH || sc_tokid == DOT) { 468 int sep; 469 470 sep = sc_tokid; 471 expect(NUMBER); 472 mday = atol(sc_token); 473 if (token() == sep) { 474 expect(NUMBER); 475 year = atol(sc_token); 476 token(); 477 } 478 479 /* 480 * flip months and days for european timing 481 */ 482 if (sep == DOT) { 483 int x = mday; 484 mday = mon; 485 mon = x; 486 } 487 } else if (tlen == 6 || tlen == 8) { 488 if (tlen == 8) { 489 year = (mon % 10000) - 1900; 490 mon /= 10000; 491 } else { 492 year = mon % 100; 493 mon /= 100; 494 } 495 mday = mon % 100; 496 mon /= 100; 497 } else 498 panic("garbled time"); 499 500 mon--; 501 if (mon < 0 || mon > 11 || mday < 1 || mday > 31) 502 panic("garbled time"); 503 504 assign_date(tm, mday, mon, year); 505 break; 506 } /* case */ 507 } /* month */ 508 509 510 /* Global functions */ 511 512 time_t 513 parsetime(argc, argv) 514 int argc; 515 char **argv; 516 { 517 /* 518 * Do the argument parsing, die if necessary, and return the time the job 519 * should be run. 520 */ 521 time_t nowtimer, runtimer; 522 struct tm nowtime, runtime; 523 int hr = 0; 524 /* this MUST be initialized to zero for midnight/noon/teatime */ 525 526 nowtimer = time(NULL); 527 nowtime = *localtime(&nowtimer); 528 529 runtime = nowtime; 530 runtime.tm_sec = 0; 531 runtime.tm_isdst = 0; 532 533 if (argc <= optind) 534 usage(); 535 536 init_scanner(argc-optind, argv+optind); 537 538 switch (token()) { 539 case NOW: /* now is optional prefix for PLUS tree */ 540 expect(PLUS); 541 case PLUS: 542 plus(&runtime); 543 break; 544 545 case NUMBER: 546 tod(&runtime); 547 month(&runtime); 548 break; 549 550 /* 551 * evil coding for TEATIME|NOON|MIDNIGHT - we've initialised 552 * hr to zero up above, then fall into this case in such a 553 * way so we add +12 +4 hours to it for teatime, +12 hours 554 * to it for noon, and nothing at all for midnight, then 555 * set our runtime to that hour before leaping into the 556 * month scanner 557 */ 558 case TEATIME: 559 hr += 4; 560 case NOON: 561 hr += 12; 562 case MIDNIGHT: 563 if (runtime.tm_hour >= hr) 564 runtime.tm_mday++; 565 runtime.tm_hour = hr; 566 runtime.tm_min = 0; 567 token(); 568 /* fall through to month setting */ 569 default: 570 month(&runtime); 571 break; 572 } /* ugly case statement */ 573 expect(EOF); 574 575 /* 576 * adjust for daylight savings time 577 */ 578 runtime.tm_isdst = -1; 579 runtimer = mktime(&runtime); 580 if (runtime.tm_isdst > 0) { 581 runtimer -= 3600; 582 runtimer = mktime(&runtime); 583 } 584 585 if (runtimer < 0) 586 panic("garbled time"); 587 588 if (nowtimer > runtimer) 589 panic("Trying to travel back in time"); 590 591 return runtimer; 592 } /* parsetime */ 593
Indexes created Wed Sep 24 14:09:57 GMT 2025