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