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(format, t, pt, ptlim, warnp, loc) 131 const char * format; 132 const struct tm * const t; 133 char * pt; 134 const char * const ptlim; 135 int * warnp; 136 locale_t loc; 137 { 138 int Ealternative, Oalternative, PadIndex; 139 struct lc_time_T *tptr = __get_current_time_locale(loc); 140 141 for ( ; *format; ++format) { 142 if (*format == '%') { 143 Ealternative = 0; 144 Oalternative = 0; 145 PadIndex = PAD_DEFAULT; 146 label: 147 switch (*++format) { 148 case '\0': 149 --format; 150 break; 151 case 'A': 152 pt = _add((t->tm_wday < 0 || 153 t->tm_wday >= DAYSPERWEEK) ? 154 "?" : tptr->weekday[t->tm_wday], 155 pt, ptlim); 156 continue; 157 case 'a': 158 pt = _add((t->tm_wday < 0 || 159 t->tm_wday >= DAYSPERWEEK) ? 160 "?" : tptr->wday[t->tm_wday], 161 pt, ptlim); 162 continue; 163 case 'B': 164 pt = _add((t->tm_mon < 0 || 165 t->tm_mon >= MONSPERYEAR) ? 166 "?" : (Oalternative ? tptr->alt_month : 167 tptr->month)[t->tm_mon], 168 pt, ptlim); 169 continue; 170 case 'b': 171 case 'h': 172 pt = _add((t->tm_mon < 0 || 173 t->tm_mon >= MONSPERYEAR) ? 174 "?" : tptr->mon[t->tm_mon], 175 pt, ptlim); 176 continue; 177 case 'C': 178 /* 179 * %C used to do a... 180 * _fmt("%a %b %e %X %Y", t); 181 * ...whereas now POSIX 1003.2 calls for 182 * something completely different. 183 * (ado, 1993-05-24) 184 */ 185 pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 0, 186 pt, ptlim, loc); 187 continue; 188 case 'c': 189 { 190 int warn2 = IN_SOME; 191 192 pt = _fmt(tptr->c_fmt, t, pt, ptlim, &warn2, loc); 193 if (warn2 == IN_ALL) 194 warn2 = IN_THIS; 195 if (warn2 > *warnp) 196 *warnp = warn2; 197 } 198 continue; 199 case 'D': 200 pt = _fmt("%m/%d/%y", t, pt, ptlim, warnp, loc); 201 continue; 202 case 'd': 203 pt = _conv(t->tm_mday, 204 fmt_padding[PAD_FMT_DAYOFMONTH][PadIndex], 205 pt, ptlim, loc); 206 continue; 207 case 'E': 208 if (Ealternative || Oalternative) 209 break; 210 Ealternative++; 211 goto label; 212 case 'O': 213 /* 214 * C99 locale modifiers. 215 * The sequences 216 * %Ec %EC %Ex %EX %Ey %EY 217 * %Od %oe %OH %OI %Om %OM 218 * %OS %Ou %OU %OV %Ow %OW %Oy 219 * are supposed to provide alternate 220 * representations. 221 * 222 * FreeBSD extension 223 * %OB 224 */ 225 if (Ealternative || Oalternative) 226 break; 227 Oalternative++; 228 goto label; 229 case 'e': 230 pt = _conv(t->tm_mday, 231 fmt_padding[PAD_FMT_SDAYOFMONTH][PadIndex], 232 pt, ptlim, loc); 233 continue; 234 case 'F': 235 pt = _fmt("%Y-%m-%d", t, pt, ptlim, warnp, loc); 236 continue; 237 case 'H': 238 pt = _conv(t->tm_hour, fmt_padding[PAD_FMT_HMS][PadIndex], 239 pt, ptlim, loc); 240 continue; 241 case 'I': 242 pt = _conv((t->tm_hour % 12) ? 243 (t->tm_hour % 12) : 12, 244 fmt_padding[PAD_FMT_HMS][PadIndex], 245 pt, ptlim, loc); 246 continue; 247 case 'j': 248 pt = _conv(t->tm_yday + 1, 249 fmt_padding[PAD_FMT_DAYOFYEAR][PadIndex], 250 pt, ptlim, loc); 251 continue; 252 case 'k': 253 /* 254 * This used to be... 255 * _conv(t->tm_hour % 12 ? 256 * t->tm_hour % 12 : 12, 2, ' '); 257 * ...and has been changed to the below to 258 * match SunOS 4.1.1 and Arnold Robbins' 259 * strftime version 3.0. That is, "%k" and 260 * "%l" have been swapped. 261 * (ado, 1993-05-24) 262 */ 263 pt = _conv(t->tm_hour, fmt_padding[PAD_FMT_SHMS][PadIndex], 264 pt, ptlim, loc); 265 continue; 266 #ifdef KITCHEN_SINK 267 case 'K': 268 /* 269 ** After all this time, still unclaimed! 270 */ 271 pt = _add("kitchen sink", pt, ptlim); 272 continue; 273 #endif /* defined KITCHEN_SINK */ 274 case 'l': 275 /* 276 * This used to be... 277 * _conv(t->tm_hour, 2, ' '); 278 * ...and has been changed to the below to 279 * match SunOS 4.1.1 and Arnold Robbin's 280 * strftime version 3.0. That is, "%k" and 281 * "%l" have been swapped. 282 * (ado, 1993-05-24) 283 */ 284 pt = _conv((t->tm_hour % 12) ? 285 (t->tm_hour % 12) : 12, 286 fmt_padding[PAD_FMT_SHMS][PadIndex], 287 pt, ptlim, loc); 288 continue; 289 case 'M': 290 pt = _conv(t->tm_min, fmt_padding[PAD_FMT_HMS][PadIndex], 291 pt, ptlim, loc); 292 continue; 293 case 'm': 294 pt = _conv(t->tm_mon + 1, 295 fmt_padding[PAD_FMT_MONTH][PadIndex], 296 pt, ptlim, loc); 297 continue; 298 case 'n': 299 pt = _add("\n", pt, ptlim); 300 continue; 301 case 'p': 302 pt = _add((t->tm_hour >= (HOURSPERDAY / 2)) ? 303 tptr->pm : tptr->am, 304 pt, ptlim); 305 continue; 306 case 'R': 307 pt = _fmt("%H:%M", t, pt, ptlim, warnp, loc); 308 continue; 309 case 'r': 310 pt = _fmt(tptr->ampm_fmt, t, pt, ptlim, 311 warnp, loc); 312 continue; 313 case 'S': 314 pt = _conv(t->tm_sec, fmt_padding[PAD_FMT_HMS][PadIndex], 315 pt, ptlim, loc); 316 continue; 317 case 's': 318 { 319 struct tm tm; 320 char buf[INT_STRLEN_MAXIMUM( 321 time_t) + 1]; 322 time_t mkt; 323 324 tm = *t; 325 mkt = mktime(&tm); 326 if (TYPE_SIGNED(time_t)) 327 (void) sprintf_l(buf, loc, "%ld", 328 (long) mkt); 329 else (void) sprintf_l(buf, loc, "%lu", 330 (unsigned long) mkt); 331 pt = _add(buf, pt, ptlim); 332 } 333 continue; 334 case 'T': 335 pt = _fmt("%H:%M:%S", t, pt, ptlim, warnp, loc); 336 continue; 337 case 't': 338 pt = _add("\t", pt, ptlim); 339 continue; 340 case 'U': 341 pt = _conv((t->tm_yday + DAYSPERWEEK - 342 t->tm_wday) / DAYSPERWEEK, 343 fmt_padding[PAD_FMT_WEEKOFYEAR][PadIndex], 344 pt, ptlim, loc); 345 continue; 346 case 'u': 347 /* 348 * From Arnold Robbins' strftime version 3.0: 349 * "ISO 8601: Weekday as a decimal number 350 * [1 (Monday) - 7]" 351 * (ado, 1993-05-24) 352 */ 353 pt = _conv((t->tm_wday == 0) ? 354 DAYSPERWEEK : t->tm_wday, 355 "%d", pt, ptlim, loc); 356 continue; 357 case 'V': /* ISO 8601 week number */ 358 case 'G': /* ISO 8601 year (four digits) */ 359 case 'g': /* ISO 8601 year (two digits) */ 360 /* 361 * From Arnold Robbins' strftime version 3.0: "the week number of the 362 * year (the first Monday as the first day of week 1) as a decimal number 363 * (01-53)." 364 * (ado, 1993-05-24) 365 * 366 * From "http://www.ft.uni-erlangen.de/~mskuhn/iso-time.html" by Markus Kuhn: 367 * "Week 01 of a year is per definition the first week which has the 368 * Thursday in this year, which is equivalent to the week which contains 369 * the fourth day of January. In other words, the first week of a new year 370 * is the week which has the majority of its days in the new year. Week 01 371 * might also contain days from the previous year and the week before week 372 * 01 of a year is the last week (52 or 53) of the previous year even if 373 * it contains days from the new year. A week starts with Monday (day 1) 374 * and ends with Sunday (day 7). For example, the first week of the year 375 * 1997 lasts from 1996-12-30 to 1997-01-05..." 376 * (ado, 1996-01-02) 377 */ 378 { 379 int year; 380 int base; 381 int yday; 382 int wday; 383 int w; 384 385 year = t->tm_year; 386 base = TM_YEAR_BASE; 387 yday = t->tm_yday; 388 wday = t->tm_wday; 389 for ( ; ; ) { 390 int len; 391 int bot; 392 int top; 393 394 len = isleap_sum(year, base) ? 395 DAYSPERLYEAR : 396 DAYSPERNYEAR; 397 /* 398 * What yday (-3 ... 3) does 399 * the ISO year begin on? 400 */ 401 bot = ((yday + 11 - wday) % 402 DAYSPERWEEK) - 3; 403 /* 404 * What yday does the NEXT 405 * ISO year begin on? 406 */ 407 top = bot - 408 (len % DAYSPERWEEK); 409 if (top < -3) 410 top += DAYSPERWEEK; 411 top += len; 412 if (yday >= top) { 413 ++base; 414 w = 1; 415 break; 416 } 417 if (yday >= bot) { 418 w = 1 + ((yday - bot) / 419 DAYSPERWEEK); 420 break; 421 } 422 --base; 423 yday += isleap_sum(year, base) ? 424 DAYSPERLYEAR : 425 DAYSPERNYEAR; 426 } 427 #ifdef XPG4_1994_04_09 428 if ((w == 52 && 429 t->tm_mon == TM_JANUARY) || 430 (w == 1 && 431 t->tm_mon == TM_DECEMBER)) 432 w = 53; 433 #endif /* defined XPG4_1994_04_09 */ 434 if (*format == 'V') 435 pt = _conv(w, fmt_padding[PAD_FMT_WEEKOFYEAR][PadIndex], 436 pt, ptlim, loc); 437 else if (*format == 'g') { 438 *warnp = IN_ALL; 439 pt = _yconv(year, base, 0, 1, 440 pt, ptlim, loc); 441 } else pt = _yconv(year, base, 1, 1, 442 pt, ptlim, loc); 443 } 444 continue; 445 case 'v': 446 /* 447 * From Arnold Robbins' strftime version 3.0: 448 * "date as dd-bbb-YYYY" 449 * (ado, 1993-05-24) 450 */ 451 pt = _fmt("%e-%b-%Y", t, pt, ptlim, warnp, loc); 452 continue; 453 case 'W': 454 pt = _conv((t->tm_yday + DAYSPERWEEK - 455 (t->tm_wday ? 456 (t->tm_wday - 1) : 457 (DAYSPERWEEK - 1))) / DAYSPERWEEK, 458 fmt_padding[PAD_FMT_WEEKOFYEAR][PadIndex], 459 pt, ptlim, loc); 460 continue; 461 case 'w': 462 pt = _conv(t->tm_wday, "%d", pt, ptlim, loc); 463 continue; 464 case 'X': 465 pt = _fmt(tptr->X_fmt, t, pt, ptlim, warnp, loc); 466 continue; 467 case 'x': 468 { 469 int warn2 = IN_SOME; 470 471 pt = _fmt(tptr->x_fmt, t, pt, ptlim, &warn2, loc); 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 = _yconv(t->tm_year, TM_YEAR_BASE, 0, 1, 481 pt, ptlim, loc); 482 continue; 483 case 'Y': 484 pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 1, 485 pt, ptlim, loc); 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 548 sign = "+"; 549 pt = _add(sign, pt, ptlim); 550 diff /= SECSPERMIN; 551 diff = (diff / MINSPERHOUR) * 100 + 552 (diff % MINSPERHOUR); 553 pt = _conv(diff, 554 fmt_padding[PAD_FMT_YEAR][PadIndex], 555 pt, ptlim, loc); 556 } 557 continue; 558 case '+': 559 pt = _fmt(tptr->date_fmt, t, pt, ptlim, 560 warnp, loc); 561 continue; 562 case '-': 563 if (PadIndex != PAD_DEFAULT) 564 break; 565 PadIndex = PAD_LESS; 566 goto label; 567 case '_': 568 if (PadIndex != PAD_DEFAULT) 569 break; 570 PadIndex = PAD_SPACE; 571 goto label; 572 case '0': 573 if (PadIndex != PAD_DEFAULT) 574 break; 575 PadIndex = PAD_ZERO; 576 goto label; 577 case '%': 578 /* 579 * X311J/88-090 (4.12.3.5): if conversion char is 580 * undefined, behavior is undefined. Print out the 581 * character itself as printf(3) also does. 582 */ 583 default: 584 break; 585 } 586 } 587 if (pt == ptlim) 588 break; 589 *pt++ = *format; 590 } 591 return (pt); 592 } 593 594 static char * 595 _conv(n, format, pt, ptlim, loc) 596 const int n; 597 const char * const format; 598 char * const pt; 599 const char * const ptlim; 600 locale_t loc; 601 { 602 char buf[INT_STRLEN_MAXIMUM(int) + 1]; 603 604 (void) sprintf_l(buf, loc, format, n); 605 return _add(buf, pt, ptlim); 606 } 607 608 static char * 609 _add(str, pt, ptlim) 610 const char * str; 611 char * pt; 612 const char * const ptlim; 613 { 614 while (pt < ptlim && (*pt = *str++) != '\0') 615 ++pt; 616 return (pt); 617 } 618 619 /* 620 * POSIX and the C Standard are unclear or inconsistent about 621 * what %C and %y do if the year is negative or exceeds 9999. 622 * Use the convention that %C concatenated with %y yields the 623 * same output as %Y, and that %Y contains at least 4 bytes, 624 * with more only if necessary. 625 */ 626 627 static char * 628 _yconv(a, b, convert_top, convert_yy, pt, ptlim, loc) 629 const int a; 630 const int b; 631 const int convert_top; 632 const int convert_yy; 633 char * pt; 634 const char * const ptlim; 635 locale_t loc; 636 { 637 register int lead; 638 register int trail; 639 640 #define DIVISOR 100 641 trail = a % DIVISOR + b % DIVISOR; 642 lead = a / DIVISOR + b / DIVISOR + trail / DIVISOR; 643 trail %= DIVISOR; 644 if (trail < 0 && lead > 0) { 645 trail += DIVISOR; 646 --lead; 647 } else if (lead < 0 && trail > 0) { 648 trail -= DIVISOR; 649 ++lead; 650 } 651 if (convert_top) { 652 if (lead == 0 && trail < 0) 653 pt = _add("-0", pt, ptlim); 654 else pt = _conv(lead, "%02d", pt, ptlim, loc); 655 } 656 if (convert_yy) 657 pt = _conv(((trail < 0) ? -trail : trail), "%02d", pt, 658 ptlim, loc); 659 return (pt); 660 } 661