strftime.c revision 1.1.1.1
1 #ifndef lint 2 #ifndef NOID 3 static char elsieid[] = "@(#)strftime.c 7.62"; 4 /* 5 ** Based on the UCB version with the ID appearing below. 6 ** This is ANSIish only when "multibyte character == plain character". 7 */ 8 #endif /* !defined NOID */ 9 #endif /* !defined lint */ 10 11 #include "private.h" 12 13 /* 14 ** Copyright (c) 1989 The Regents of the University of California. 15 ** All rights reserved. 16 ** 17 ** Redistribution and use in source and binary forms are permitted 18 ** provided that the above copyright notice and this paragraph are 19 ** duplicated in all such forms and that any documentation, 20 ** advertising materials, and other materials related to such 21 ** distribution and use acknowledge that the software was developed 22 ** by the University of California, Berkeley. The name of the 23 ** University may not be used to endorse or promote products derived 24 ** from this software without specific prior written permission. 25 ** THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 26 ** IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 27 ** WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. 28 */ 29 30 #ifndef LIBC_SCCS 31 #ifndef lint 32 static const char sccsid[] = "@(#)strftime.c 5.4 (Berkeley) 3/14/89"; 33 #endif /* !defined lint */ 34 #endif /* !defined LIBC_SCCS */ 35 36 #include "tzfile.h" 37 #include "fcntl.h" 38 #include "locale.h" 39 40 struct lc_time_T { 41 const char * mon[MONSPERYEAR]; 42 const char * month[MONSPERYEAR]; 43 const char * wday[DAYSPERWEEK]; 44 const char * weekday[DAYSPERWEEK]; 45 const char * X_fmt; 46 const char * x_fmt; 47 const char * c_fmt; 48 const char * am; 49 const char * pm; 50 const char * date_fmt; 51 }; 52 53 #ifdef LOCALE_HOME 54 #include "sys/stat.h" 55 static struct lc_time_T localebuf; 56 static struct lc_time_T * _loc P((void)); 57 #define Locale _loc() 58 #endif /* defined LOCALE_HOME */ 59 #ifndef LOCALE_HOME 60 #define Locale (&C_time_locale) 61 #endif /* !defined LOCALE_HOME */ 62 63 static const struct lc_time_T C_time_locale = { 64 { 65 "Jan", "Feb", "Mar", "Apr", "May", "Jun", 66 "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" 67 }, { 68 "January", "February", "March", "April", "May", "June", 69 "July", "August", "September", "October", "November", "December" 70 }, { 71 "Sun", "Mon", "Tue", "Wed", 72 "Thu", "Fri", "Sat" 73 }, { 74 "Sunday", "Monday", "Tuesday", "Wednesday", 75 "Thursday", "Friday", "Saturday" 76 }, 77 78 /* X_fmt */ 79 "%H:%M:%S", 80 81 /* 82 ** x_fmt 83 ** C99 requires this format. 84 ** Using just numbers (as here) makes Quakers happier; 85 ** it's also compatible with SVR4. 86 */ 87 "%m/%d/%y", 88 89 /* 90 ** c_fmt 91 ** C99 requires this format. 92 ** Previously this code used "%D %X", but we now conform to C99. 93 ** Note that 94 ** "%a %b %d %H:%M:%S %Y" 95 ** is used by Solaris 2.3. 96 */ 97 "%a %b %e %T %Y", 98 99 /* am */ 100 "AM", 101 102 /* pm */ 103 "PM", 104 105 /* date_fmt */ 106 "%a %b %e %H:%M:%S %Z %Y" 107 }; 108 109 static char * _add P((const char *, char *, const char *)); 110 static char * _conv P((int, const char *, char *, const char *)); 111 static char * _fmt P((const char *, const struct tm *, char *, const char *, int *)); 112 113 size_t strftime P((char *, size_t, const char *, const struct tm *)); 114 115 extern char * tzname[]; 116 117 #ifndef YEAR_2000_NAME 118 #define YEAR_2000_NAME "CHECK_STRFTIME_FORMATS_FOR_TWO_DIGIT_YEARS" 119 #endif /* !defined YEAR_2000_NAME */ 120 121 122 #define IN_NONE 0 123 #define IN_SOME 1 124 #define IN_THIS 2 125 #define IN_ALL 3 126 127 size_t 128 strftime(s, maxsize, format, t) 129 char * const s; 130 const size_t maxsize; 131 const char * const format; 132 const struct tm * const t; 133 { 134 char * p; 135 int warn; 136 137 tzset(); 138 #ifdef LOCALE_HOME 139 localebuf.mon[0] = 0; 140 #endif /* defined LOCALE_HOME */ 141 warn = IN_NONE; 142 p = _fmt(((format == NULL) ? "%c" : format), t, s, s + maxsize, &warn); 143 #ifndef NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU 144 if (warn != IN_NONE && getenv(YEAR_2000_NAME) != NULL) { 145 (void) fprintf(stderr, "\n"); 146 if (format == NULL) 147 (void) fprintf(stderr, "NULL strftime format "); 148 else (void) fprintf(stderr, "strftime format \"%s\" ", 149 format); 150 (void) fprintf(stderr, "yields only two digits of years in "); 151 if (warn == IN_SOME) 152 (void) fprintf(stderr, "some locales"); 153 else if (warn == IN_THIS) 154 (void) fprintf(stderr, "the current locale"); 155 else (void) fprintf(stderr, "all locales"); 156 (void) fprintf(stderr, "\n"); 157 } 158 #endif /* !defined NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU */ 159 if (p == s + maxsize) 160 return 0; 161 *p = '\0'; 162 return p - s; 163 } 164 165 static char * 166 _fmt(format, t, pt, ptlim, warnp) 167 const char * format; 168 const struct tm * const t; 169 char * pt; 170 const char * const ptlim; 171 int * warnp; 172 { 173 for ( ; *format; ++format) { 174 if (*format == '%') { 175 label: 176 switch (*++format) { 177 case '\0': 178 --format; 179 break; 180 case 'A': 181 pt = _add((t->tm_wday < 0 || 182 t->tm_wday >= DAYSPERWEEK) ? 183 "?" : Locale->weekday[t->tm_wday], 184 pt, ptlim); 185 continue; 186 case 'a': 187 pt = _add((t->tm_wday < 0 || 188 t->tm_wday >= DAYSPERWEEK) ? 189 "?" : Locale->wday[t->tm_wday], 190 pt, ptlim); 191 continue; 192 case 'B': 193 pt = _add((t->tm_mon < 0 || 194 t->tm_mon >= MONSPERYEAR) ? 195 "?" : Locale->month[t->tm_mon], 196 pt, ptlim); 197 continue; 198 case 'b': 199 case 'h': 200 pt = _add((t->tm_mon < 0 || 201 t->tm_mon >= MONSPERYEAR) ? 202 "?" : Locale->mon[t->tm_mon], 203 pt, ptlim); 204 continue; 205 case 'C': 206 /* 207 ** %C used to do a... 208 ** _fmt("%a %b %e %X %Y", t); 209 ** ...whereas now POSIX 1003.2 calls for 210 ** something completely different. 211 ** (ado, 1993-05-24) 212 */ 213 pt = _conv((t->tm_year + TM_YEAR_BASE) / 100, 214 "%02d", pt, ptlim); 215 continue; 216 case 'c': 217 { 218 int warn2 = IN_SOME; 219 220 pt = _fmt(Locale->c_fmt, t, pt, ptlim, warnp); 221 if (warn2 == IN_ALL) 222 warn2 = IN_THIS; 223 if (warn2 > *warnp) 224 *warnp = warn2; 225 } 226 continue; 227 case 'D': 228 pt = _fmt("%m/%d/%y", t, pt, ptlim, warnp); 229 continue; 230 case 'd': 231 pt = _conv(t->tm_mday, "%02d", pt, ptlim); 232 continue; 233 case 'E': 234 case 'O': 235 /* 236 ** C99 locale modifiers. 237 ** The sequences 238 ** %Ec %EC %Ex %EX %Ey %EY 239 ** %Od %oe %OH %OI %Om %OM 240 ** %OS %Ou %OU %OV %Ow %OW %Oy 241 ** are supposed to provide alternate 242 ** representations. 243 */ 244 goto label; 245 case 'e': 246 pt = _conv(t->tm_mday, "%2d", pt, ptlim); 247 continue; 248 case 'F': 249 pt = _fmt("%Y-%m-%d", t, pt, ptlim, warnp); 250 continue; 251 case 'H': 252 pt = _conv(t->tm_hour, "%02d", pt, ptlim); 253 continue; 254 case 'I': 255 pt = _conv((t->tm_hour % 12) ? 256 (t->tm_hour % 12) : 12, 257 "%02d", pt, ptlim); 258 continue; 259 case 'j': 260 pt = _conv(t->tm_yday + 1, "%03d", pt, ptlim); 261 continue; 262 case 'k': 263 /* 264 ** This used to be... 265 ** _conv(t->tm_hour % 12 ? 266 ** t->tm_hour % 12 : 12, 2, ' '); 267 ** ...and has been changed to the below to 268 ** match SunOS 4.1.1 and Arnold Robbins' 269 ** strftime version 3.0. That is, "%k" and 270 ** "%l" have been swapped. 271 ** (ado, 1993-05-24) 272 */ 273 pt = _conv(t->tm_hour, "%2d", pt, ptlim); 274 continue; 275 #ifdef KITCHEN_SINK 276 case 'K': 277 /* 278 ** After all this time, still unclaimed! 279 */ 280 pt = _add("kitchen sink", pt, ptlim); 281 continue; 282 #endif /* defined KITCHEN_SINK */ 283 case 'l': 284 /* 285 ** This used to be... 286 ** _conv(t->tm_hour, 2, ' '); 287 ** ...and has been changed to the below to 288 ** match SunOS 4.1.1 and Arnold Robbin's 289 ** strftime version 3.0. That is, "%k" and 290 ** "%l" have been swapped. 291 ** (ado, 1993-05-24) 292 */ 293 pt = _conv((t->tm_hour % 12) ? 294 (t->tm_hour % 12) : 12, 295 "%2d", pt, ptlim); 296 continue; 297 case 'M': 298 pt = _conv(t->tm_min, "%02d", pt, ptlim); 299 continue; 300 case 'm': 301 pt = _conv(t->tm_mon + 1, "%02d", pt, ptlim); 302 continue; 303 case 'n': 304 pt = _add("\n", pt, ptlim); 305 continue; 306 case 'p': 307 pt = _add((t->tm_hour >= (HOURSPERDAY / 2)) ? 308 Locale->pm : 309 Locale->am, 310 pt, ptlim); 311 continue; 312 case 'R': 313 pt = _fmt("%H:%M", t, pt, ptlim, warnp); 314 continue; 315 case 'r': 316 pt = _fmt("%I:%M:%S %p", t, pt, ptlim, warnp); 317 continue; 318 case 'S': 319 pt = _conv(t->tm_sec, "%02d", pt, ptlim); 320 continue; 321 case 's': 322 { 323 struct tm tm; 324 char buf[INT_STRLEN_MAXIMUM( 325 time_t) + 1]; 326 time_t mkt; 327 328 tm = *t; 329 mkt = mktime(&tm); 330 if (TYPE_SIGNED(time_t)) 331 (void) sprintf(buf, "%ld", 332 (long) mkt); 333 else (void) sprintf(buf, "%lu", 334 (unsigned long) mkt); 335 pt = _add(buf, pt, ptlim); 336 } 337 continue; 338 case 'T': 339 pt = _fmt("%H:%M:%S", t, pt, ptlim, warnp); 340 continue; 341 case 't': 342 pt = _add("\t", pt, ptlim); 343 continue; 344 case 'U': 345 pt = _conv((t->tm_yday + DAYSPERWEEK - 346 t->tm_wday) / DAYSPERWEEK, 347 "%02d", pt, ptlim); 348 continue; 349 case 'u': 350 /* 351 ** From Arnold Robbins' strftime version 3.0: 352 ** "ISO 8601: Weekday as a decimal number 353 ** [1 (Monday) - 7]" 354 ** (ado, 1993-05-24) 355 */ 356 pt = _conv((t->tm_wday == 0) ? 357 DAYSPERWEEK : t->tm_wday, 358 "%d", pt, ptlim); 359 continue; 360 case 'V': /* ISO 8601 week number */ 361 case 'G': /* ISO 8601 year (four digits) */ 362 case 'g': /* ISO 8601 year (two digits) */ 363 /* 364 ** From Arnold Robbins' strftime version 3.0: "the week number of the 365 ** year (the first Monday as the first day of week 1) as a decimal number 366 ** (01-53)." 367 ** (ado, 1993-05-24) 368 ** 369 ** From "http://www.ft.uni-erlangen.de/~mskuhn/iso-time.html" by Markus Kuhn: 370 ** "Week 01 of a year is per definition the first week which has the 371 ** Thursday in this year, which is equivalent to the week which contains 372 ** the fourth day of January. In other words, the first week of a new year 373 ** is the week which has the majority of its days in the new year. Week 01 374 ** might also contain days from the previous year and the week before week 375 ** 01 of a year is the last week (52 or 53) of the previous year even if 376 ** it contains days from the new year. A week starts with Monday (day 1) 377 ** and ends with Sunday (day 7). For example, the first week of the year 378 ** 1997 lasts from 1996-12-30 to 1997-01-05..." 379 ** (ado, 1996-01-02) 380 */ 381 { 382 int year; 383 int yday; 384 int wday; 385 int w; 386 387 year = t->tm_year + TM_YEAR_BASE; 388 yday = t->tm_yday; 389 wday = t->tm_wday; 390 for ( ; ; ) { 391 int len; 392 int bot; 393 int top; 394 395 len = isleap(year) ? 396 DAYSPERLYEAR : 397 DAYSPERNYEAR; 398 /* 399 ** What yday (-3 ... 3) does 400 ** the ISO year begin on? 401 */ 402 bot = ((yday + 11 - wday) % 403 DAYSPERWEEK) - 3; 404 /* 405 ** What yday does the NEXT 406 ** ISO year begin on? 407 */ 408 top = bot - 409 (len % DAYSPERWEEK); 410 if (top < -3) 411 top += DAYSPERWEEK; 412 top += len; 413 if (yday >= top) { 414 ++year; 415 w = 1; 416 break; 417 } 418 if (yday >= bot) { 419 w = 1 + ((yday - bot) / 420 DAYSPERWEEK); 421 break; 422 } 423 --year; 424 yday += isleap(year) ? 425 DAYSPERLYEAR : 426 DAYSPERNYEAR; 427 } 428 #ifdef XPG4_1994_04_09 429 if ((w == 52 430 && t->tm_mon == TM_JANUARY) 431 || (w == 1 432 && t->tm_mon == TM_DECEMBER)) 433 w = 53; 434 #endif /* defined XPG4_1994_04_09 */ 435 if (*format == 'V') 436 pt = _conv(w, "%02d", 437 pt, ptlim); 438 else if (*format == 'g') { 439 *warnp = IN_ALL; 440 pt = _conv(year % 100, "%02d", 441 pt, ptlim); 442 } else pt = _conv(year, "%04d", 443 pt, ptlim); 444 } 445 continue; 446 case 'v': 447 /* 448 ** From Arnold Robbins' strftime version 3.0: 449 ** "date as dd-bbb-YYYY" 450 ** (ado, 1993-05-24) 451 */ 452 pt = _fmt("%e-%b-%Y", t, pt, ptlim, warnp); 453 continue; 454 case 'W': 455 pt = _conv((t->tm_yday + DAYSPERWEEK - 456 (t->tm_wday ? 457 (t->tm_wday - 1) : 458 (DAYSPERWEEK - 1))) / DAYSPERWEEK, 459 "%02d", pt, ptlim); 460 continue; 461 case 'w': 462 pt = _conv(t->tm_wday, "%d", pt, ptlim); 463 continue; 464 case 'X': 465 pt = _fmt(Locale->X_fmt, t, pt, ptlim, warnp); 466 continue; 467 case 'x': 468 { 469 int warn2 = IN_SOME; 470 471 pt = _fmt(Locale->x_fmt, t, pt, ptlim, &warn2); 472 if (warn2 == IN_ALL) 473 warn2 = IN_THIS; 474 if (warn2 > *warnp) 475 *warnp = warn2; 476 } 477 continue; 478 case 'y': 479 *warnp = IN_ALL; 480 pt = _conv((t->tm_year + TM_YEAR_BASE) % 100, 481 "%02d", pt, ptlim); 482 continue; 483 case 'Y': 484 pt = _conv(t->tm_year + TM_YEAR_BASE, "%04d", 485 pt, ptlim); 486 continue; 487 case 'Z': 488 #ifdef TM_ZONE 489 if (t->TM_ZONE != NULL) 490 pt = _add(t->TM_ZONE, pt, ptlim); 491 else 492 #endif /* defined TM_ZONE */ 493 if (t->tm_isdst >= 0) 494 pt = _add(tzname[t->tm_isdst != 0], 495 pt, ptlim); 496 /* 497 ** C99 says that %Z must be replaced by the 498 ** empty string if the time zone is not 499 ** determinable. 500 */ 501 continue; 502 case 'z': 503 { 504 int diff; 505 char const * sign; 506 507 if (t->tm_isdst < 0) 508 continue; 509 #ifdef TM_GMTOFF 510 diff = t->TM_GMTOFF; 511 #else /* !defined TM_GMTOFF */ 512 /* 513 ** C99 says that the UTC offset must 514 ** be computed by looking only at 515 ** tm_isdst. This requirement is 516 ** incorrect, since it means the code 517 ** must rely on magic (in this case 518 ** altzone and timezone), and the 519 ** magic might not have the correct 520 ** offset. Doing things correctly is 521 ** tricky and requires disobeying C99; 522 ** see GNU C strftime for details. 523 ** For now, punt and conform to the 524 ** standard, even though it's incorrect. 525 ** 526 ** C99 says that %z must be replaced by the 527 ** empty string if the time zone is not 528 ** determinable, so output nothing if the 529 ** appropriate variables are not available. 530 */ 531 if (t->tm_isdst == 0) 532 #ifdef USG_COMPAT 533 diff = -timezone; 534 #else /* defined USG_COMPAT */ 535 continue; 536 #endif /* !defined USG_COMPAT */ 537 else 538 #ifdef ALTZONE 539 diff = -altzone; 540 #else /* !defined ALTZONE */ 541 continue; 542 #endif /* !defined ALTZONE */ 543 #endif /* !defined TM_GMTOFF */ 544 if (diff < 0) { 545 sign = "-"; 546 diff = -diff; 547 } else sign = "+"; 548 pt = _add(sign, pt, ptlim); 549 diff /= 60; 550 pt = _conv((diff/60)*100 + diff%60, 551 "%04d", pt, ptlim); 552 } 553 continue; 554 case '+': 555 pt = _fmt(Locale->date_fmt, t, pt, ptlim, 556 warnp); 557 continue; 558 case '%': 559 /* 560 ** X311J/88-090 (4.12.3.5): if conversion char is 561 ** undefined, behavior is undefined. Print out the 562 ** character itself as printf(3) also does. 563 */ 564 default: 565 break; 566 } 567 } 568 if (pt == ptlim) 569 break; 570 *pt++ = *format; 571 } 572 return pt; 573 } 574 575 static char * 576 _conv(n, format, pt, ptlim) 577 const int n; 578 const char * const format; 579 char * const pt; 580 const char * const ptlim; 581 { 582 char buf[INT_STRLEN_MAXIMUM(int) + 1]; 583 584 (void) sprintf(buf, format, n); 585 return _add(buf, pt, ptlim); 586 } 587 588 static char * 589 _add(str, pt, ptlim) 590 const char * str; 591 char * pt; 592 const char * const ptlim; 593 { 594 while (pt < ptlim && (*pt = *str++) != '\0') 595 ++pt; 596 return pt; 597 } 598 599 #ifdef LOCALE_HOME 600 static struct lc_time_T * 601 _loc P((void)) 602 { 603 static const char locale_home[] = LOCALE_HOME; 604 static const char lc_time[] = "LC_TIME"; 605 static char * locale_buf; 606 static char locale_buf_C[] = "C"; 607 608 int fd; 609 int oldsun; /* "...ain't got nothin' to do..." */ 610 char * lbuf; 611 char * name; 612 char * p; 613 const char ** ap; 614 const char * plim; 615 char filename[FILENAME_MAX]; 616 struct stat st; 617 size_t namesize; 618 size_t bufsize; 619 620 /* 621 ** Use localebuf.mon[0] to signal whether locale is already set up. 622 */ 623 if (localebuf.mon[0]) 624 return &localebuf; 625 name = setlocale(LC_TIME, (char *) NULL); 626 if (name == NULL || *name == '\0') 627 goto no_locale; 628 /* 629 ** If the locale name is the same as our cache, use the cache. 630 */ 631 lbuf = locale_buf; 632 if (lbuf != NULL && strcmp(name, lbuf) == 0) { 633 p = lbuf; 634 for (ap = (const char **) &localebuf; 635 ap < (const char **) (&localebuf + 1); 636 ++ap) 637 *ap = p += strlen(p) + 1; 638 return &localebuf; 639 } 640 /* 641 ** Slurp the locale file into the cache. 642 */ 643 namesize = strlen(name) + 1; 644 if (sizeof(filename) < 645 sizeof(locale_home) + namesize + sizeof(lc_time)) 646 goto no_locale; 647 oldsun = 0; 648 (void) sprintf(filename, "%s/%s/%s", locale_home, name, lc_time); 649 fd = open(filename, O_RDONLY); 650 if (fd < 0) { 651 /* 652 ** Old Sun systems have a different naming and data convention. 653 */ 654 oldsun = 1; 655 (void) sprintf(filename, "%s/%s/%s", locale_home, 656 lc_time, name); 657 fd = open(filename, O_RDONLY); 658 if (fd < 0) 659 goto no_locale; 660 } 661 if (fstat(fd, &st) != 0) 662 goto bad_locale; 663 if (st.st_size <= 0) 664 goto bad_locale; 665 bufsize = namesize + st.st_size; 666 locale_buf = NULL; 667 lbuf = (lbuf == NULL || lbuf == locale_buf_C) ? 668 malloc(bufsize) : realloc(lbuf, bufsize); 669 if (lbuf == NULL) 670 goto bad_locale; 671 (void) strcpy(lbuf, name); 672 p = lbuf + namesize; 673 plim = p + st.st_size; 674 if (read(fd, p, (size_t) st.st_size) != st.st_size) 675 goto bad_lbuf; 676 if (close(fd) != 0) 677 goto bad_lbuf; 678 /* 679 ** Parse the locale file into localebuf. 680 */ 681 if (plim[-1] != '\n') 682 goto bad_lbuf; 683 for (ap = (const char **) &localebuf; 684 ap < (const char **) (&localebuf + 1); 685 ++ap) { 686 if (p == plim) 687 goto bad_lbuf; 688 *ap = p; 689 while (*p != '\n') 690 ++p; 691 *p++ = '\0'; 692 } 693 if (oldsun) { 694 /* 695 ** SunOS 4 used an obsolescent format; see localdtconv(3). 696 ** c_fmt had the ``short format for dates and times together'' 697 ** (SunOS 4 date, "%a %b %e %T %Z %Y" in the C locale); 698 ** date_fmt had the ``long format for dates'' 699 ** (SunOS 4 strftime %C, "%A, %B %e, %Y" in the C locale). 700 ** Discard the latter in favor of the former. 701 */ 702 localebuf.date_fmt = localebuf.c_fmt; 703 } 704 /* 705 ** Record the successful parse in the cache. 706 */ 707 locale_buf = lbuf; 708 709 return &localebuf; 710 711 bad_lbuf: 712 free(lbuf); 713 bad_locale: 714 (void) close(fd); 715 no_locale: 716 localebuf = C_time_locale; 717 locale_buf = locale_buf_C; 718 return &localebuf; 719 } 720 #endif /* defined LOCALE_HOME */ 721
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