1 /* 2 * Copyright (c) 1989 The Regents of the University of California. 3 * All rights reserved. 4 * 5 * Copyright (c) 2011 The FreeBSD Foundation 6 * All rights reserved. 7 * Portions of this software were developed by David Chisnall 8 * under sponsorship from the FreeBSD Foundation. 9 * 10 * Redistribution and use in source and binary forms are permitted 11 * provided that the above copyright notice and this paragraph are 12 * duplicated in all such forms and that any documentation, 13 * advertising materials, and other materials related to such 14 * distribution and use acknowledge that the software was developed 15 * by the University of California, Berkeley. The name of the 16 * University may not be used to endorse or promote products derived 17 * from this software without specific prior written permission. 18 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 20 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. 21 */ 22 23 #ifndef lint 24 #ifndef NOID 25 static const char elsieid[] = "@(#)strftime.3 8.3"; 26 /* 27 * Based on the UCB version with the ID appearing below. 28 * This is ANSIish only when "multibyte character == plain character". 29 */ 30 #endif /* !defined NOID */ 31 #endif /* !defined lint */ 32 33 #include "namespace.h" 34 #include "private.h" 35 36 #if defined(LIBC_SCCS) && !defined(lint) 37 static const char sccsid[] = "@(#)strftime.c 5.4 (Berkeley) 3/14/89"; 38 #endif /* LIBC_SCCS and not lint */ 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include "tzfile.h" 43 #include <fcntl.h> 44 #include <sys/stat.h> 45 #include "un-namespace.h" 46 #include "timelocal.h" 47 48 static char * _add(const char *, char *, const char *); 49 static char * _conv(int, const char *, char *, const char *, locale_t); 50 static char * _fmt(const char *, const struct tm *, char *, const char *, 51 int *, locale_t); 52 static char * _yconv(int, int, int, int, char *, const char *, locale_t); 53 54 extern char * tzname[]; 55 56 #ifndef YEAR_2000_NAME 57 #define YEAR_2000_NAME "CHECK_STRFTIME_FORMATS_FOR_TWO_DIGIT_YEARS" 58 #endif /* !defined YEAR_2000_NAME */ 59 60 #define IN_NONE 0 61 #define IN_SOME 1 62 #define IN_THIS 2 63 #define IN_ALL 3 64 65 #define PAD_DEFAULT 0 66 #define PAD_LESS 1 67 #define PAD_SPACE 2 68 #define PAD_ZERO 3 69 70 static const char fmt_padding[][4][5] = { 71 /* DEFAULT, LESS, SPACE, ZERO */ 72 #define PAD_FMT_MONTHDAY 0 73 #define PAD_FMT_HMS 0 74 #define PAD_FMT_CENTURY 0 75 #define PAD_FMT_SHORTYEAR 0 76 #define PAD_FMT_MONTH 0 77 #define PAD_FMT_WEEKOFYEAR 0 78 #define PAD_FMT_DAYOFMONTH 0 79 { "%02d", "%d", "%2d", "%02d" }, 80 #define PAD_FMT_SDAYOFMONTH 1 81 #define PAD_FMT_SHMS 1 82 { "%2d", "%d", "%2d", "%02d" }, 83 #define PAD_FMT_DAYOFYEAR 2 84 { "%03d", "%d", "%3d", "%03d" }, 85 #define PAD_FMT_YEAR 3 86 { "%04d", "%d", "%4d", "%04d" } 87 }; 88 89 size_t 90 strftime_l(char * __restrict s, size_t maxsize, const char * __restrict format, 91 const struct tm * __restrict t, locale_t loc) 92 { 93 char * p; 94 int warn; 95 FIX_LOCALE(loc); 96 97 tzset(); 98 warn = IN_NONE; 99 p = _fmt(((format == NULL) ? "%c" : format), t, s, s + maxsize, &warn, loc); 100 #ifndef NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU 101 if (warn != IN_NONE && getenv(YEAR_2000_NAME) != NULL) { 102 (void) fprintf_l(stderr, loc, "\n"); 103 if (format == NULL) 104 (void) fputs("NULL strftime format ", stderr); 105 else (void) fprintf_l(stderr, loc, "strftime format \"%s\" ", 106 format); 107 (void) fputs("yields only two digits of years in ", stderr); 108 if (warn == IN_SOME) 109 (void) fputs("some locales", stderr); 110 else if (warn == IN_THIS) 111 (void) fputs("the current locale", stderr); 112 else (void) fputs("all locales", stderr); 113 (void) fputs("\n", stderr); 114 } 115 #endif /* !defined NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU */ 116 if (p == s + maxsize) 117 return (0); 118 *p = '\0'; 119 return p - s; 120 } 121 122 size_t 123 strftime(char * __restrict s, size_t maxsize, const char * __restrict format, 124 const struct tm * __restrict t) 125 { 126 return strftime_l(s, maxsize, format, t, __get_locale()); 127 } 128 129 static char * 130 _fmt(const char *format, const struct tm * const t, char *pt, 131 const char * const ptlim, int *warnp, locale_t loc) 132 { 133 int Ealternative, Oalternative, PadIndex; 134 struct lc_time_T *tptr = __get_current_time_locale(loc); 135 136 for ( ; *format; ++format) { 137 if (*format == '%') { 138 Ealternative = 0; 139 Oalternative = 0; 140 PadIndex = PAD_DEFAULT; 141 label: 142 switch (*++format) { 143 case '\0': 144 --format; 145 break; 146 case 'A': 147 pt = _add((t->tm_wday < 0 || 148 t->tm_wday >= DAYSPERWEEK) ? 149 "?" : tptr->weekday[t->tm_wday], 150 pt, ptlim); 151 continue; 152 case 'a': 153 pt = _add((t->tm_wday < 0 || 154 t->tm_wday >= DAYSPERWEEK) ? 155 "?" : tptr->wday[t->tm_wday], 156 pt, ptlim); 157 continue; 158 case 'B': 159 pt = _add((t->tm_mon < 0 || 160 t->tm_mon >= MONSPERYEAR) ? 161 "?" : (Oalternative ? tptr->alt_month : 162 tptr->month)[t->tm_mon], 163 pt, ptlim); 164 continue; 165 case 'b': 166 case 'h': 167 pt = _add((t->tm_mon < 0 || 168 t->tm_mon >= MONSPERYEAR) ? 169 "?" : tptr->mon[t->tm_mon], 170 pt, ptlim); 171 continue; 172 case 'C': 173 /* 174 * %C used to do a... 175 * _fmt("%a %b %e %X %Y", t); 176 * ...whereas now POSIX 1003.2 calls for 177 * something completely different. 178 * (ado, 1993-05-24) 179 */ 180 pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 0, 181 pt, ptlim, loc); 182 continue; 183 case 'c': 184 { 185 int warn2 = IN_SOME; 186 187 pt = _fmt(tptr->c_fmt, t, pt, ptlim, &warn2, loc); 188 if (warn2 == IN_ALL) 189 warn2 = IN_THIS; 190 if (warn2 > *warnp) 191 *warnp = warn2; 192 } 193 continue; 194 case 'D': 195 pt = _fmt("%m/%d/%y", t, pt, ptlim, warnp, loc); 196 continue; 197 case 'd': 198 pt = _conv(t->tm_mday, 199 fmt_padding[PAD_FMT_DAYOFMONTH][PadIndex], 200 pt, ptlim, loc); 201 continue; 202 case 'E': 203 if (Ealternative || Oalternative) 204 break; 205 Ealternative++; 206 goto label; 207 case 'O': 208 /* 209 * C99 locale modifiers. 210 * The sequences 211 * %Ec %EC %Ex %EX %Ey %EY 212 * %Od %oe %OH %OI %Om %OM 213 * %OS %Ou %OU %OV %Ow %OW %Oy 214 * are supposed to provide alternate 215 * representations. 216 * 217 * FreeBSD extension 218 * %OB 219 */ 220 if (Ealternative || Oalternative) 221 break; 222 Oalternative++; 223 goto label; 224 case 'e': 225 pt = _conv(t->tm_mday, 226 fmt_padding[PAD_FMT_SDAYOFMONTH][PadIndex], 227 pt, ptlim, loc); 228 continue; 229 case 'F': 230 pt = _fmt("%Y-%m-%d", t, pt, ptlim, warnp, loc); 231 continue; 232 case 'H': 233 pt = _conv(t->tm_hour, fmt_padding[PAD_FMT_HMS][PadIndex], 234 pt, ptlim, loc); 235 continue; 236 case 'I': 237 pt = _conv((t->tm_hour % 12) ? 238 (t->tm_hour % 12) : 12, 239 fmt_padding[PAD_FMT_HMS][PadIndex], 240 pt, ptlim, loc); 241 continue; 242 case 'j': 243 pt = _conv(t->tm_yday + 1, 244 fmt_padding[PAD_FMT_DAYOFYEAR][PadIndex], 245 pt, ptlim, loc); 246 continue; 247 case 'k': 248 /* 249 * This used to be... 250 * _conv(t->tm_hour % 12 ? 251 * t->tm_hour % 12 : 12, 2, ' '); 252 * ...and has been changed to the below to 253 * match SunOS 4.1.1 and Arnold Robbins' 254 * strftime version 3.0. That is, "%k" and 255 * "%l" have been swapped. 256 * (ado, 1993-05-24) 257 */ 258 pt = _conv(t->tm_hour, fmt_padding[PAD_FMT_SHMS][PadIndex], 259 pt, ptlim, loc); 260 continue; 261 #ifdef KITCHEN_SINK 262 case 'K': 263 /* 264 ** After all this time, still unclaimed! 265 */ 266 pt = _add("kitchen sink", pt, ptlim); 267 continue; 268 #endif /* defined KITCHEN_SINK */ 269 case 'l': 270 /* 271 * This used to be... 272 * _conv(t->tm_hour, 2, ' '); 273 * ...and has been changed to the below to 274 * match SunOS 4.1.1 and Arnold Robbin's 275 * strftime version 3.0. That is, "%k" and 276 * "%l" have been swapped. 277 * (ado, 1993-05-24) 278 */ 279 pt = _conv((t->tm_hour % 12) ? 280 (t->tm_hour % 12) : 12, 281 fmt_padding[PAD_FMT_SHMS][PadIndex], 282 pt, ptlim, loc); 283 continue; 284 case 'M': 285 pt = _conv(t->tm_min, fmt_padding[PAD_FMT_HMS][PadIndex], 286 pt, ptlim, loc); 287 continue; 288 case 'm': 289 pt = _conv(t->tm_mon + 1, 290 fmt_padding[PAD_FMT_MONTH][PadIndex], 291 pt, ptlim, loc); 292 continue; 293 case 'n': 294 pt = _add("\n", pt, ptlim); 295 continue; 296 case 'p': 297 pt = _add((t->tm_hour >= (HOURSPERDAY / 2)) ? 298 tptr->pm : tptr->am, 299 pt, ptlim); 300 continue; 301 case 'R': 302 pt = _fmt("%H:%M", t, pt, ptlim, warnp, loc); 303 continue; 304 case 'r': 305 pt = _fmt(tptr->ampm_fmt, t, pt, ptlim, 306 warnp, loc); 307 continue; 308 case 'S': 309 pt = _conv(t->tm_sec, fmt_padding[PAD_FMT_HMS][PadIndex], 310 pt, ptlim, loc); 311 continue; 312 case 's': 313 { 314 struct tm tm; 315 char buf[INT_STRLEN_MAXIMUM( 316 time_t) + 1]; 317 time_t mkt; 318 319 tm = *t; 320 mkt = mktime(&tm); 321 if (TYPE_SIGNED(time_t)) 322 (void) sprintf_l(buf, loc, "%ld", 323 (long) mkt); 324 else (void) sprintf_l(buf, loc, "%lu", 325 (unsigned long) mkt); 326 pt = _add(buf, pt, ptlim); 327 } 328 continue; 329 case 'T': 330 pt = _fmt("%H:%M:%S", t, pt, ptlim, warnp, loc); 331 continue; 332 case 't': 333 pt = _add("\t", pt, ptlim); 334 continue; 335 case 'U': 336 pt = _conv((t->tm_yday + DAYSPERWEEK - 337 t->tm_wday) / DAYSPERWEEK, 338 fmt_padding[PAD_FMT_WEEKOFYEAR][PadIndex], 339 pt, ptlim, loc); 340 continue; 341 case 'u': 342 /* 343 * From Arnold Robbins' strftime version 3.0: 344 * "ISO 8601: Weekday as a decimal number 345 * [1 (Monday) - 7]" 346 * (ado, 1993-05-24) 347 */ 348 pt = _conv((t->tm_wday == 0) ? 349 DAYSPERWEEK : t->tm_wday, 350 "%d", pt, ptlim, loc); 351 continue; 352 case 'V': /* ISO 8601 week number */ 353 case 'G': /* ISO 8601 year (four digits) */ 354 case 'g': /* ISO 8601 year (two digits) */ 355 /* 356 * From Arnold Robbins' strftime version 3.0: "the week number of the 357 * year (the first Monday as the first day of week 1) as a decimal number 358 * (01-53)." 359 * (ado, 1993-05-24) 360 * 361 * From "http://www.ft.uni-erlangen.de/~mskuhn/iso-time.html" by Markus Kuhn: 362 * "Week 01 of a year is per definition the first week which has the 363 * Thursday in this year, which is equivalent to the week which contains 364 * the fourth day of January. In other words, the first week of a new year 365 * is the week which has the majority of its days in the new year. Week 01 366 * might also contain days from the previous year and the week before week 367 * 01 of a year is the last week (52 or 53) of the previous year even if 368 * it contains days from the new year. A week starts with Monday (day 1) 369 * and ends with Sunday (day 7). For example, the first week of the year 370 * 1997 lasts from 1996-12-30 to 1997-01-05..." 371 * (ado, 1996-01-02) 372 */ 373 { 374 int year; 375 int base; 376 int yday; 377 int wday; 378 int w; 379 380 year = t->tm_year; 381 base = TM_YEAR_BASE; 382 yday = t->tm_yday; 383 wday = t->tm_wday; 384 for ( ; ; ) { 385 int len; 386 int bot; 387 int top; 388 389 len = isleap_sum(year, base) ? 390 DAYSPERLYEAR : 391 DAYSPERNYEAR; 392 /* 393 * What yday (-3 ... 3) does 394 * the ISO year begin on? 395 */ 396 bot = ((yday + 11 - wday) % 397 DAYSPERWEEK) - 3; 398 /* 399 * What yday does the NEXT 400 * ISO year begin on? 401 */ 402 top = bot - 403 (len % DAYSPERWEEK); 404 if (top < -3) 405 top += DAYSPERWEEK; 406 top += len; 407 if (yday >= top) { 408 ++base; 409 w = 1; 410 break; 411 } 412 if (yday >= bot) { 413 w = 1 + ((yday - bot) / 414 DAYSPERWEEK); 415 break; 416 } 417 --base; 418 yday += isleap_sum(year, base) ? 419 DAYSPERLYEAR : 420 DAYSPERNYEAR; 421 } 422 #ifdef XPG4_1994_04_09 423 if ((w == 52 && 424 t->tm_mon == TM_JANUARY) || 425 (w == 1 && 426 t->tm_mon == TM_DECEMBER)) 427 w = 53; 428 #endif /* defined XPG4_1994_04_09 */ 429 if (*format == 'V') 430 pt = _conv(w, fmt_padding[PAD_FMT_WEEKOFYEAR][PadIndex], 431 pt, ptlim, loc); 432 else if (*format == 'g') { 433 *warnp = IN_ALL; 434 pt = _yconv(year, base, 0, 1, 435 pt, ptlim, loc); 436 } else pt = _yconv(year, base, 1, 1, 437 pt, ptlim, loc); 438 } 439 continue; 440 case 'v': 441 /* 442 * From Arnold Robbins' strftime version 3.0: 443 * "date as dd-bbb-YYYY" 444 * (ado, 1993-05-24) 445 */ 446 pt = _fmt("%e-%b-%Y", t, pt, ptlim, warnp, loc); 447 continue; 448 case 'W': 449 pt = _conv((t->tm_yday + DAYSPERWEEK - 450 (t->tm_wday ? 451 (t->tm_wday - 1) : 452 (DAYSPERWEEK - 1))) / DAYSPERWEEK, 453 fmt_padding[PAD_FMT_WEEKOFYEAR][PadIndex], 454 pt, ptlim, loc); 455 continue; 456 case 'w': 457 pt = _conv(t->tm_wday, "%d", pt, ptlim, loc); 458 continue; 459 case 'X': 460 pt = _fmt(tptr->X_fmt, t, pt, ptlim, warnp, loc); 461 continue; 462 case 'x': 463 { 464 int warn2 = IN_SOME; 465 466 pt = _fmt(tptr->x_fmt, t, pt, ptlim, &warn2, loc); 467 if (warn2 == IN_ALL) 468 warn2 = IN_THIS; 469 if (warn2 > *warnp) 470 *warnp = warn2; 471 } 472 continue; 473 case 'y': 474 *warnp = IN_ALL; 475 pt = _yconv(t->tm_year, TM_YEAR_BASE, 0, 1, 476 pt, ptlim, loc); 477 continue; 478 case 'Y': 479 pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 1, 480 pt, ptlim, loc); 481 continue; 482 case 'Z': 483 #ifdef TM_ZONE 484 if (t->TM_ZONE != NULL) 485 pt = _add(t->TM_ZONE, pt, ptlim); 486 else 487 #endif /* defined TM_ZONE */ 488 if (t->tm_isdst >= 0) 489 pt = _add(tzname[t->tm_isdst != 0], 490 pt, ptlim); 491 /* 492 * C99 says that %Z must be replaced by the 493 * empty string if the time zone is not 494 * determinable. 495 */ 496 continue; 497 case 'z': 498 { 499 int diff; 500 char const * sign; 501 502 if (t->tm_isdst < 0) 503 continue; 504 #ifdef TM_GMTOFF 505 diff = t->TM_GMTOFF; 506 #else /* !defined TM_GMTOFF */ 507 /* 508 * C99 says that the UTC offset must 509 * be computed by looking only at 510 * tm_isdst. This requirement is 511 * incorrect, since it means the code 512 * must rely on magic (in this case 513 * altzone and timezone), and the 514 * magic might not have the correct 515 * offset. Doing things correctly is 516 * tricky and requires disobeying C99; 517 * see GNU C strftime for details. 518 * For now, punt and conform to the 519 * standard, even though it's incorrect. 520 * 521 * C99 says that %z must be replaced by the 522 * empty string if the time zone is not 523 * determinable, so output nothing if the 524 * appropriate variables are not available. 525 */ 526 if (t->tm_isdst == 0) 527 #ifdef USG_COMPAT 528 diff = -timezone; 529 #else /* !defined USG_COMPAT */ 530 continue; 531 #endif /* !defined USG_COMPAT */ 532 else 533 #ifdef ALTZONE 534 diff = -altzone; 535 #else /* !defined ALTZONE */ 536 continue; 537 #endif /* !defined ALTZONE */ 538 #endif /* !defined TM_GMTOFF */ 539 if (diff < 0) { 540 sign = "-"; 541 diff = -diff; 542 } else 543 sign = "+"; 544 pt = _add(sign, pt, ptlim); 545 diff /= SECSPERMIN; 546 diff = (diff / MINSPERHOUR) * 100 + 547 (diff % MINSPERHOUR); 548 pt = _conv(diff, 549 fmt_padding[PAD_FMT_YEAR][PadIndex], 550 pt, ptlim, loc); 551 } 552 continue; 553 case '+': 554 pt = _fmt(tptr->date_fmt, t, pt, ptlim, 555 warnp, loc); 556 continue; 557 case '-': 558 if (PadIndex != PAD_DEFAULT) 559 break; 560 PadIndex = PAD_LESS; 561 goto label; 562 case '_': 563 if (PadIndex != PAD_DEFAULT) 564 break; 565 PadIndex = PAD_SPACE; 566 goto label; 567 case '0': 568 if (PadIndex != PAD_DEFAULT) 569 break; 570 PadIndex = PAD_ZERO; 571 goto label; 572 case '%': 573 /* 574 * X311J/88-090 (4.12.3.5): if conversion char is 575 * undefined, behavior is undefined. Print out the 576 * character itself as printf(3) also does. 577 */ 578 default: 579 break; 580 } 581 } 582 if (pt == ptlim) 583 break; 584 *pt++ = *format; 585 } 586 return (pt); 587 } 588 589 static char * 590 _conv(const int n, const char * const format, char * const pt, 591 const char * const ptlim, locale_t loc) 592 { 593 char buf[INT_STRLEN_MAXIMUM(int) + 1]; 594 595 (void) sprintf_l(buf, loc, format, n); 596 return _add(buf, pt, ptlim); 597 } 598 599 static char * 600 _add(const char *str, char *pt, const char * const ptlim) 601 { 602 while (pt < ptlim && (*pt = *str++) != '\0') 603 ++pt; 604 return (pt); 605 } 606 607 /* 608 * POSIX and the C Standard are unclear or inconsistent about 609 * what %C and %y do if the year is negative or exceeds 9999. 610 * Use the convention that %C concatenated with %y yields the 611 * same output as %Y, and that %Y contains at least 4 bytes, 612 * with more only if necessary. 613 */ 614 615 static char * 616 _yconv(const int a, const int b, const int convert_top, const int convert_yy, 617 char *pt, const char * const ptlim, locale_t loc) 618 { 619 register int lead; 620 register int trail; 621 622 #define DIVISOR 100 623 trail = a % DIVISOR + b % DIVISOR; 624 lead = a / DIVISOR + b / DIVISOR + trail / DIVISOR; 625 trail %= DIVISOR; 626 if (trail < 0 && lead > 0) { 627 trail += DIVISOR; 628 --lead; 629 } else if (lead < 0 && trail > 0) { 630 trail -= DIVISOR; 631 ++lead; 632 } 633 if (convert_top) { 634 if (lead == 0 && trail < 0) 635 pt = _add("-0", pt, ptlim); 636 else pt = _conv(lead, "%02d", pt, ptlim, loc); 637 } 638 if (convert_yy) 639 pt = _conv(((trail < 0) ? -trail : trail), "%02d", pt, 640 ptlim, loc); 641 return (pt); 642 } 643