1 /* 2 * SPDX-License-Identifier: BSD-4.3TAHOE 3 * 4 * Copyright (c) 1989 The Regents of the University of California. 5 * All rights reserved. 6 * 7 * Copyright (c) 2011 The FreeBSD Foundation 8 * 9 * Portions of this software were developed by David Chisnall 10 * under sponsorship from the FreeBSD Foundation. 11 * 12 * Redistribution and use in source and binary forms are permitted 13 * provided that the above copyright notice and this paragraph are 14 * duplicated in all such forms and that any documentation, 15 * advertising materials, and other materials related to such 16 * distribution and use acknowledge that the software was developed 17 * by the University of California, Berkeley. The name of the 18 * University may not be used to endorse or promote products derived 19 * from this software without specific prior written permission. 20 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 21 * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED 22 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. 23 */ 24 25 #include "namespace.h" 26 #include "private.h" 27 28 #include "tzfile.h" 29 #include <fcntl.h> 30 #include <sys/stat.h> 31 #include <stdio.h> 32 #include "un-namespace.h" 33 #include "timelocal.h" 34 35 static char * _add(const char *, char *, const char *); 36 static char * _conv(int, const char *, char *, const char *, locale_t); 37 static char * _fmt(const char *, const struct tm *, char *, const char *, 38 int *, locale_t); 39 static char * _yconv(int, int, int, int, char *, const char *, locale_t); 40 41 extern char * tzname[]; 42 43 #ifndef YEAR_2000_NAME 44 #define YEAR_2000_NAME "CHECK_STRFTIME_FORMATS_FOR_TWO_DIGIT_YEARS" 45 #endif /* !defined YEAR_2000_NAME */ 46 47 #define IN_NONE 0 48 #define IN_SOME 1 49 #define IN_THIS 2 50 #define IN_ALL 3 51 52 #define PAD_DEFAULT 0 53 #define PAD_LESS 1 54 #define PAD_SPACE 2 55 #define PAD_ZERO 3 56 57 static const char fmt_padding[][4][5] = { 58 /* DEFAULT, LESS, SPACE, ZERO */ 59 #define PAD_FMT_MONTHDAY 0 60 #define PAD_FMT_HMS 0 61 #define PAD_FMT_CENTURY 0 62 #define PAD_FMT_SHORTYEAR 0 63 #define PAD_FMT_MONTH 0 64 #define PAD_FMT_WEEKOFYEAR 0 65 #define PAD_FMT_DAYOFMONTH 0 66 { "%02d", "%d", "%2d", "%02d" }, 67 #define PAD_FMT_SDAYOFMONTH 1 68 #define PAD_FMT_SHMS 1 69 { "%2d", "%d", "%2d", "%02d" }, 70 #define PAD_FMT_DAYOFYEAR 2 71 { "%03d", "%d", "%3d", "%03d" }, 72 #define PAD_FMT_YEAR 3 73 { "%04d", "%d", "%4d", "%04d" } 74 }; 75 76 size_t 77 strftime_l(char * __restrict s, size_t maxsize, const char * __restrict format, 78 const struct tm * __restrict t, locale_t loc) 79 { 80 char * p; 81 int warn; 82 FIX_LOCALE(loc); 83 84 tzset(); 85 warn = IN_NONE; 86 p = _fmt(((format == NULL) ? "%c" : format), t, s, s + maxsize, &warn, loc); 87 #ifndef NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU 88 if (warn != IN_NONE && getenv(YEAR_2000_NAME) != NULL) { 89 (void) fprintf_l(stderr, loc, "\n"); 90 if (format == NULL) 91 (void) fputs("NULL strftime format ", stderr); 92 else (void) fprintf_l(stderr, loc, "strftime format \"%s\" ", 93 format); 94 (void) fputs("yields only two digits of years in ", stderr); 95 if (warn == IN_SOME) 96 (void) fputs("some locales", stderr); 97 else if (warn == IN_THIS) 98 (void) fputs("the current locale", stderr); 99 else (void) fputs("all locales", stderr); 100 (void) fputs("\n", stderr); 101 } 102 #endif /* !defined NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU */ 103 if (p == s + maxsize) 104 return (0); 105 *p = '\0'; 106 return p - s; 107 } 108 109 size_t 110 strftime(char * __restrict s, size_t maxsize, const char * __restrict format, 111 const struct tm * __restrict t) 112 { 113 return strftime_l(s, maxsize, format, t, __get_locale()); 114 } 115 116 static char * 117 _fmt(const char *format, const struct tm * const t, char *pt, 118 const char * const ptlim, int *warnp, locale_t loc) 119 { 120 int Ealternative, Oalternative, PadIndex; 121 struct lc_time_T *tptr = __get_current_time_locale(loc); 122 123 for ( ; *format; ++format) { 124 if (*format == '%') { 125 Ealternative = 0; 126 Oalternative = 0; 127 PadIndex = PAD_DEFAULT; 128 label: 129 switch (*++format) { 130 case '\0': 131 --format; 132 break; 133 case 'A': 134 pt = _add((t->tm_wday < 0 || 135 t->tm_wday >= DAYSPERWEEK) ? 136 "?" : tptr->weekday[t->tm_wday], 137 pt, ptlim); 138 continue; 139 case 'a': 140 pt = _add((t->tm_wday < 0 || 141 t->tm_wday >= DAYSPERWEEK) ? 142 "?" : tptr->wday[t->tm_wday], 143 pt, ptlim); 144 continue; 145 case 'B': 146 pt = _add((t->tm_mon < 0 || 147 t->tm_mon >= MONSPERYEAR) ? 148 "?" : (Oalternative ? tptr->alt_month : 149 tptr->month)[t->tm_mon], 150 pt, ptlim); 151 continue; 152 case 'b': 153 case 'h': 154 pt = _add((t->tm_mon < 0 || 155 t->tm_mon >= MONSPERYEAR) ? 156 "?" : tptr->mon[t->tm_mon], 157 pt, ptlim); 158 continue; 159 case 'C': 160 /* 161 * %C used to do a... 162 * _fmt("%a %b %e %X %Y", t); 163 * ...whereas now POSIX 1003.2 calls for 164 * something completely different. 165 * (ado, 1993-05-24) 166 */ 167 pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 0, 168 pt, ptlim, loc); 169 continue; 170 case 'c': 171 { 172 int warn2 = IN_SOME; 173 174 pt = _fmt(tptr->c_fmt, t, pt, ptlim, &warn2, loc); 175 if (warn2 == IN_ALL) 176 warn2 = IN_THIS; 177 if (warn2 > *warnp) 178 *warnp = warn2; 179 } 180 continue; 181 case 'D': 182 pt = _fmt("%m/%d/%y", t, pt, ptlim, warnp, loc); 183 continue; 184 case 'd': 185 pt = _conv(t->tm_mday, 186 fmt_padding[PAD_FMT_DAYOFMONTH][PadIndex], 187 pt, ptlim, loc); 188 continue; 189 case 'E': 190 if (Ealternative || Oalternative) 191 break; 192 Ealternative++; 193 goto label; 194 case 'O': 195 /* 196 * C99 locale modifiers. 197 * The sequences 198 * %Ec %EC %Ex %EX %Ey %EY 199 * %Od %oe %OH %OI %Om %OM 200 * %OS %Ou %OU %OV %Ow %OW %Oy 201 * are supposed to provide alternate 202 * representations. 203 * 204 * FreeBSD extension 205 * %OB 206 */ 207 if (Ealternative || Oalternative) 208 break; 209 Oalternative++; 210 goto label; 211 case 'e': 212 pt = _conv(t->tm_mday, 213 fmt_padding[PAD_FMT_SDAYOFMONTH][PadIndex], 214 pt, ptlim, loc); 215 continue; 216 case 'F': 217 pt = _fmt("%Y-%m-%d", t, pt, ptlim, warnp, loc); 218 continue; 219 case 'H': 220 pt = _conv(t->tm_hour, fmt_padding[PAD_FMT_HMS][PadIndex], 221 pt, ptlim, loc); 222 continue; 223 case 'I': 224 pt = _conv((t->tm_hour % 12) ? 225 (t->tm_hour % 12) : 12, 226 fmt_padding[PAD_FMT_HMS][PadIndex], 227 pt, ptlim, loc); 228 continue; 229 case 'j': 230 pt = _conv(t->tm_yday + 1, 231 fmt_padding[PAD_FMT_DAYOFYEAR][PadIndex], 232 pt, ptlim, loc); 233 continue; 234 case 'k': 235 /* 236 * This used to be... 237 * _conv(t->tm_hour % 12 ? 238 * t->tm_hour % 12 : 12, 2, ' '); 239 * ...and has been changed to the below to 240 * match SunOS 4.1.1 and Arnold Robbins' 241 * strftime version 3.0. That is, "%k" and 242 * "%l" have been swapped. 243 * (ado, 1993-05-24) 244 */ 245 pt = _conv(t->tm_hour, fmt_padding[PAD_FMT_SHMS][PadIndex], 246 pt, ptlim, loc); 247 continue; 248 #ifdef KITCHEN_SINK 249 case 'K': 250 /* 251 ** After all this time, still unclaimed! 252 */ 253 pt = _add("kitchen sink", pt, ptlim); 254 continue; 255 #endif /* defined KITCHEN_SINK */ 256 case 'l': 257 /* 258 * This used to be... 259 * _conv(t->tm_hour, 2, ' '); 260 * ...and has been changed to the below to 261 * match SunOS 4.1.1 and Arnold Robbin's 262 * strftime version 3.0. That is, "%k" and 263 * "%l" have been swapped. 264 * (ado, 1993-05-24) 265 */ 266 pt = _conv((t->tm_hour % 12) ? 267 (t->tm_hour % 12) : 12, 268 fmt_padding[PAD_FMT_SHMS][PadIndex], 269 pt, ptlim, loc); 270 continue; 271 case 'M': 272 pt = _conv(t->tm_min, fmt_padding[PAD_FMT_HMS][PadIndex], 273 pt, ptlim, loc); 274 continue; 275 case 'm': 276 pt = _conv(t->tm_mon + 1, 277 fmt_padding[PAD_FMT_MONTH][PadIndex], 278 pt, ptlim, loc); 279 continue; 280 case 'n': 281 pt = _add("\n", pt, ptlim); 282 continue; 283 case 'p': 284 pt = _add((t->tm_hour >= (HOURSPERDAY / 2)) ? 285 tptr->pm : tptr->am, 286 pt, ptlim); 287 continue; 288 case 'R': 289 pt = _fmt("%H:%M", t, pt, ptlim, warnp, loc); 290 continue; 291 case 'r': 292 pt = _fmt(tptr->ampm_fmt, t, pt, ptlim, 293 warnp, loc); 294 continue; 295 case 'S': 296 pt = _conv(t->tm_sec, fmt_padding[PAD_FMT_HMS][PadIndex], 297 pt, ptlim, loc); 298 continue; 299 case 's': 300 { 301 struct tm tm; 302 char buf[INT_STRLEN_MAXIMUM( 303 time_t) + 1]; 304 time_t mkt; 305 306 tm = *t; 307 mkt = timeoff(&tm, t->tm_gmtoff); 308 if (TYPE_SIGNED(time_t)) 309 (void) sprintf_l(buf, loc, "%ld", 310 (long) mkt); 311 else (void) sprintf_l(buf, loc, "%lu", 312 (unsigned long) mkt); 313 pt = _add(buf, pt, ptlim); 314 } 315 continue; 316 case 'T': 317 pt = _fmt("%H:%M:%S", t, pt, ptlim, warnp, loc); 318 continue; 319 case 't': 320 pt = _add("\t", pt, ptlim); 321 continue; 322 case 'U': 323 pt = _conv((t->tm_yday + DAYSPERWEEK - 324 t->tm_wday) / DAYSPERWEEK, 325 fmt_padding[PAD_FMT_WEEKOFYEAR][PadIndex], 326 pt, ptlim, loc); 327 continue; 328 case 'u': 329 /* 330 * From Arnold Robbins' strftime version 3.0: 331 * "ISO 8601: Weekday as a decimal number 332 * [1 (Monday) - 7]" 333 * (ado, 1993-05-24) 334 */ 335 pt = _conv((t->tm_wday == 0) ? 336 DAYSPERWEEK : t->tm_wday, 337 "%d", pt, ptlim, loc); 338 continue; 339 case 'V': /* ISO 8601 week number */ 340 case 'G': /* ISO 8601 year (four digits) */ 341 case 'g': /* ISO 8601 year (two digits) */ 342 /* 343 * From Arnold Robbins' strftime version 3.0: "the week number of the 344 * year (the first Monday as the first day of week 1) as a decimal number 345 * (01-53)." 346 * (ado, 1993-05-24) 347 * 348 * From "http://www.ft.uni-erlangen.de/~mskuhn/iso-time.html" by Markus Kuhn: 349 * "Week 01 of a year is per definition the first week which has the 350 * Thursday in this year, which is equivalent to the week which contains 351 * the fourth day of January. In other words, the first week of a new year 352 * is the week which has the majority of its days in the new year. Week 01 353 * might also contain days from the previous year and the week before week 354 * 01 of a year is the last week (52 or 53) of the previous year even if 355 * it contains days from the new year. A week starts with Monday (day 1) 356 * and ends with Sunday (day 7). For example, the first week of the year 357 * 1997 lasts from 1996-12-30 to 1997-01-05..." 358 * (ado, 1996-01-02) 359 */ 360 { 361 int year; 362 int base; 363 int yday; 364 int wday; 365 int w; 366 367 year = t->tm_year; 368 base = TM_YEAR_BASE; 369 yday = t->tm_yday; 370 wday = t->tm_wday; 371 for ( ; ; ) { 372 int len; 373 int bot; 374 int top; 375 376 len = isleap_sum(year, base) ? 377 DAYSPERLYEAR : 378 DAYSPERNYEAR; 379 /* 380 * What yday (-3 ... 3) does 381 * the ISO year begin on? 382 */ 383 bot = ((yday + 11 - wday) % 384 DAYSPERWEEK) - 3; 385 /* 386 * What yday does the NEXT 387 * ISO year begin on? 388 */ 389 top = bot - 390 (len % DAYSPERWEEK); 391 if (top < -3) 392 top += DAYSPERWEEK; 393 top += len; 394 if (yday >= top) { 395 ++base; 396 w = 1; 397 break; 398 } 399 if (yday >= bot) { 400 w = 1 + ((yday - bot) / 401 DAYSPERWEEK); 402 break; 403 } 404 --base; 405 yday += isleap_sum(year, base) ? 406 DAYSPERLYEAR : 407 DAYSPERNYEAR; 408 } 409 #ifdef XPG4_1994_04_09 410 if ((w == 52 && 411 t->tm_mon == TM_JANUARY) || 412 (w == 1 && 413 t->tm_mon == TM_DECEMBER)) 414 w = 53; 415 #endif /* defined XPG4_1994_04_09 */ 416 if (*format == 'V') 417 pt = _conv(w, fmt_padding[PAD_FMT_WEEKOFYEAR][PadIndex], 418 pt, ptlim, loc); 419 else if (*format == 'g') { 420 *warnp = IN_ALL; 421 pt = _yconv(year, base, 0, 1, 422 pt, ptlim, loc); 423 } else pt = _yconv(year, base, 1, 1, 424 pt, ptlim, loc); 425 } 426 continue; 427 case 'v': 428 /* 429 * From Arnold Robbins' strftime version 3.0: 430 * "date as dd-bbb-YYYY" 431 * (ado, 1993-05-24) 432 */ 433 pt = _fmt("%e-%b-%Y", t, pt, ptlim, warnp, loc); 434 continue; 435 case 'W': 436 pt = _conv((t->tm_yday + DAYSPERWEEK - 437 (t->tm_wday ? 438 (t->tm_wday - 1) : 439 (DAYSPERWEEK - 1))) / DAYSPERWEEK, 440 fmt_padding[PAD_FMT_WEEKOFYEAR][PadIndex], 441 pt, ptlim, loc); 442 continue; 443 case 'w': 444 pt = _conv(t->tm_wday, "%d", pt, ptlim, loc); 445 continue; 446 case 'X': 447 pt = _fmt(tptr->X_fmt, t, pt, ptlim, warnp, loc); 448 continue; 449 case 'x': 450 { 451 int warn2 = IN_SOME; 452 453 pt = _fmt(tptr->x_fmt, t, pt, ptlim, &warn2, loc); 454 if (warn2 == IN_ALL) 455 warn2 = IN_THIS; 456 if (warn2 > *warnp) 457 *warnp = warn2; 458 } 459 continue; 460 case 'y': 461 *warnp = IN_ALL; 462 pt = _yconv(t->tm_year, TM_YEAR_BASE, 0, 1, 463 pt, ptlim, loc); 464 continue; 465 case 'Y': 466 pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 1, 467 pt, ptlim, loc); 468 continue; 469 case 'Z': 470 #ifdef TM_ZONE 471 if (t->TM_ZONE != NULL) 472 pt = _add(t->TM_ZONE, pt, ptlim); 473 else 474 #endif /* defined TM_ZONE */ 475 if (t->tm_isdst >= 0) 476 pt = _add(tzname[t->tm_isdst != 0], 477 pt, ptlim); 478 /* 479 * C99 says that %Z must be replaced by the 480 * empty string if the time zone is not 481 * determinable. 482 */ 483 continue; 484 case 'z': 485 { 486 int diff; 487 char const * sign; 488 489 if (t->tm_isdst < 0) 490 continue; 491 #ifdef TM_GMTOFF 492 diff = t->TM_GMTOFF; 493 #else /* !defined TM_GMTOFF */ 494 /* 495 * C99 says that the UTC offset must 496 * be computed by looking only at 497 * tm_isdst. This requirement is 498 * incorrect, since it means the code 499 * must rely on magic (in this case 500 * altzone and timezone), and the 501 * magic might not have the correct 502 * offset. Doing things correctly is 503 * tricky and requires disobeying C99; 504 * see GNU C strftime for details. 505 * For now, punt and conform to the 506 * standard, even though it's incorrect. 507 * 508 * C99 says that %z must be replaced by the 509 * empty string if the time zone is not 510 * determinable, so output nothing if the 511 * appropriate variables are not available. 512 */ 513 if (t->tm_isdst == 0) 514 #ifdef USG_COMPAT 515 diff = -timezone; 516 #else /* !defined USG_COMPAT */ 517 continue; 518 #endif /* !defined USG_COMPAT */ 519 else 520 #ifdef ALTZONE 521 diff = -altzone; 522 #else /* !defined ALTZONE */ 523 continue; 524 #endif /* !defined ALTZONE */ 525 #endif /* !defined TM_GMTOFF */ 526 if (diff < 0) { 527 sign = "-"; 528 diff = -diff; 529 } else 530 sign = "+"; 531 pt = _add(sign, pt, ptlim); 532 diff /= SECSPERMIN; 533 diff = (diff / MINSPERHOUR) * 100 + 534 (diff % MINSPERHOUR); 535 pt = _conv(diff, 536 fmt_padding[PAD_FMT_YEAR][PadIndex], 537 pt, ptlim, loc); 538 } 539 continue; 540 case '+': 541 pt = _fmt(tptr->date_fmt, t, pt, ptlim, 542 warnp, loc); 543 continue; 544 case '-': 545 if (PadIndex != PAD_DEFAULT) 546 break; 547 PadIndex = PAD_LESS; 548 goto label; 549 case '_': 550 if (PadIndex != PAD_DEFAULT) 551 break; 552 PadIndex = PAD_SPACE; 553 goto label; 554 case '0': 555 if (PadIndex != PAD_DEFAULT) 556 break; 557 PadIndex = PAD_ZERO; 558 goto label; 559 case '%': 560 /* 561 * X311J/88-090 (4.12.3.5): if conversion char is 562 * undefined, behavior is undefined. Print out the 563 * character itself as printf(3) also does. 564 */ 565 default: 566 break; 567 } 568 } 569 if (pt == ptlim) 570 break; 571 *pt++ = *format; 572 } 573 return (pt); 574 } 575 576 static char * 577 _conv(const int n, const char * const format, char * const pt, 578 const char * const ptlim, locale_t loc) 579 { 580 char buf[INT_STRLEN_MAXIMUM(int) + 1]; 581 582 (void) sprintf_l(buf, loc, format, n); 583 return _add(buf, pt, ptlim); 584 } 585 586 static char * 587 _add(const char *str, char *pt, const char * const ptlim) 588 { 589 while (pt < ptlim && (*pt = *str++) != '\0') 590 ++pt; 591 return (pt); 592 } 593 594 /* 595 * POSIX and the C Standard are unclear or inconsistent about 596 * what %C and %y do if the year is negative or exceeds 9999. 597 * Use the convention that %C concatenated with %y yields the 598 * same output as %Y, and that %Y contains at least 4 bytes, 599 * with more only if necessary. 600 */ 601 602 static char * 603 _yconv(const int a, const int b, const int convert_top, const int convert_yy, 604 char *pt, const char * const ptlim, locale_t loc) 605 { 606 register int lead; 607 register int trail; 608 609 #define DIVISOR 100 610 trail = a % DIVISOR + b % DIVISOR; 611 lead = a / DIVISOR + b / DIVISOR + trail / DIVISOR; 612 trail %= DIVISOR; 613 if (trail < 0 && lead > 0) { 614 trail += DIVISOR; 615 --lead; 616 } else if (lead < 0 && trail > 0) { 617 trail -= DIVISOR; 618 ++lead; 619 } 620 if (convert_top) { 621 if (lead == 0 && trail < 0) 622 pt = _add("-0", pt, ptlim); 623 else pt = _conv(lead, "%02d", pt, ptlim, loc); 624 } 625 if (convert_yy) 626 pt = _conv(((trail < 0) ? -trail : trail), "%02d", pt, 627 ptlim, loc); 628 return (pt); 629 } 630