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