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 <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include "tzfile.h" 43 #include <fcntl.h> 44 #include <sys/stat.h> 45 #include <stdio.h> 46 #include "un-namespace.h" 47 #include "timelocal.h" 48 49 static char * _add(const char *, char *, const char *); 50 static char * _conv(int, const char *, char *, const char *, locale_t); 51 static char * _fmt(const char *, const struct tm *, char *, const char *, 52 int *, locale_t); 53 static char * _yconv(int, int, int, int, char *, const char *, locale_t); 54 55 extern char * tzname[]; 56 57 #ifndef YEAR_2000_NAME 58 #define YEAR_2000_NAME "CHECK_STRFTIME_FORMATS_FOR_TWO_DIGIT_YEARS" 59 #endif /* !defined YEAR_2000_NAME */ 60 61 #define IN_NONE 0 62 #define IN_SOME 1 63 #define IN_THIS 2 64 #define IN_ALL 3 65 66 #define PAD_DEFAULT 0 67 #define PAD_LESS 1 68 #define PAD_SPACE 2 69 #define PAD_ZERO 3 70 71 static const char fmt_padding[][4][5] = { 72 /* DEFAULT, LESS, SPACE, ZERO */ 73 #define PAD_FMT_MONTHDAY 0 74 #define PAD_FMT_HMS 0 75 #define PAD_FMT_CENTURY 0 76 #define PAD_FMT_SHORTYEAR 0 77 #define PAD_FMT_MONTH 0 78 #define PAD_FMT_WEEKOFYEAR 0 79 #define PAD_FMT_DAYOFMONTH 0 80 { "%02d", "%d", "%2d", "%02d" }, 81 #define PAD_FMT_SDAYOFMONTH 1 82 #define PAD_FMT_SHMS 1 83 { "%2d", "%d", "%2d", "%02d" }, 84 #define PAD_FMT_DAYOFYEAR 2 85 { "%03d", "%d", "%3d", "%03d" }, 86 #define PAD_FMT_YEAR 3 87 { "%04d", "%d", "%4d", "%04d" } 88 }; 89 90 size_t 91 strftime_l(char * __restrict s, size_t maxsize, const char * __restrict format, 92 const struct tm * __restrict t, locale_t loc) 93 { 94 char * p; 95 int warn; 96 FIX_LOCALE(loc); 97 98 tzset(); 99 warn = IN_NONE; 100 p = _fmt(((format == NULL) ? "%c" : format), t, s, s + maxsize, &warn, loc); 101 #ifndef NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU 102 if (warn != IN_NONE && getenv(YEAR_2000_NAME) != NULL) { 103 (void) fprintf_l(stderr, loc, "\n"); 104 if (format == NULL) 105 (void) fputs("NULL strftime format ", stderr); 106 else (void) fprintf_l(stderr, loc, "strftime format \"%s\" ", 107 format); 108 (void) fputs("yields only two digits of years in ", stderr); 109 if (warn == IN_SOME) 110 (void) fputs("some locales", stderr); 111 else if (warn == IN_THIS) 112 (void) fputs("the current locale", stderr); 113 else (void) fputs("all locales", stderr); 114 (void) fputs("\n", stderr); 115 } 116 #endif /* !defined NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU */ 117 if (p == s + maxsize) 118 return (0); 119 *p = '\0'; 120 return p - s; 121 } 122 123 size_t 124 strftime(char * __restrict s, size_t maxsize, const char * __restrict format, 125 const struct tm * __restrict t) 126 { 127 return strftime_l(s, maxsize, format, t, __get_locale()); 128 } 129 130 static char * 131 _fmt(const char *format, const struct tm * const t, char *pt, 132 const char * const ptlim, int *warnp, locale_t loc) 133 { 134 int Ealternative, Oalternative, PadIndex; 135 struct lc_time_T *tptr = __get_current_time_locale(loc); 136 137 for ( ; *format; ++format) { 138 if (*format == '%') { 139 Ealternative = 0; 140 Oalternative = 0; 141 PadIndex = PAD_DEFAULT; 142 label: 143 switch (*++format) { 144 case '\0': 145 --format; 146 break; 147 case 'A': 148 pt = _add((t->tm_wday < 0 || 149 t->tm_wday >= DAYSPERWEEK) ? 150 "?" : tptr->weekday[t->tm_wday], 151 pt, ptlim); 152 continue; 153 case 'a': 154 pt = _add((t->tm_wday < 0 || 155 t->tm_wday >= DAYSPERWEEK) ? 156 "?" : tptr->wday[t->tm_wday], 157 pt, ptlim); 158 continue; 159 case 'B': 160 pt = _add((t->tm_mon < 0 || 161 t->tm_mon >= MONSPERYEAR) ? 162 "?" : (Oalternative ? tptr->alt_month : 163 tptr->month)[t->tm_mon], 164 pt, ptlim); 165 continue; 166 case 'b': 167 case 'h': 168 pt = _add((t->tm_mon < 0 || 169 t->tm_mon >= MONSPERYEAR) ? 170 "?" : tptr->mon[t->tm_mon], 171 pt, ptlim); 172 continue; 173 case 'C': 174 /* 175 * %C used to do a... 176 * _fmt("%a %b %e %X %Y", t); 177 * ...whereas now POSIX 1003.2 calls for 178 * something completely different. 179 * (ado, 1993-05-24) 180 */ 181 pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 0, 182 pt, ptlim, loc); 183 continue; 184 case 'c': 185 { 186 int warn2 = IN_SOME; 187 188 pt = _fmt(tptr->c_fmt, t, pt, ptlim, &warn2, loc); 189 if (warn2 == IN_ALL) 190 warn2 = IN_THIS; 191 if (warn2 > *warnp) 192 *warnp = warn2; 193 } 194 continue; 195 case 'D': 196 pt = _fmt("%m/%d/%y", t, pt, ptlim, warnp, loc); 197 continue; 198 case 'd': 199 pt = _conv(t->tm_mday, 200 fmt_padding[PAD_FMT_DAYOFMONTH][PadIndex], 201 pt, ptlim, loc); 202 continue; 203 case 'E': 204 if (Ealternative || Oalternative) 205 break; 206 Ealternative++; 207 goto label; 208 case 'O': 209 /* 210 * C99 locale modifiers. 211 * The sequences 212 * %Ec %EC %Ex %EX %Ey %EY 213 * %Od %oe %OH %OI %Om %OM 214 * %OS %Ou %OU %OV %Ow %OW %Oy 215 * are supposed to provide alternate 216 * representations. 217 * 218 * FreeBSD extension 219 * %OB 220 */ 221 if (Ealternative || Oalternative) 222 break; 223 Oalternative++; 224 goto label; 225 case 'e': 226 pt = _conv(t->tm_mday, 227 fmt_padding[PAD_FMT_SDAYOFMONTH][PadIndex], 228 pt, ptlim, loc); 229 continue; 230 case 'F': 231 pt = _fmt("%Y-%m-%d", t, pt, ptlim, warnp, loc); 232 continue; 233 case 'H': 234 pt = _conv(t->tm_hour, fmt_padding[PAD_FMT_HMS][PadIndex], 235 pt, ptlim, loc); 236 continue; 237 case 'I': 238 pt = _conv((t->tm_hour % 12) ? 239 (t->tm_hour % 12) : 12, 240 fmt_padding[PAD_FMT_HMS][PadIndex], 241 pt, ptlim, loc); 242 continue; 243 case 'j': 244 pt = _conv(t->tm_yday + 1, 245 fmt_padding[PAD_FMT_DAYOFYEAR][PadIndex], 246 pt, ptlim, loc); 247 continue; 248 case 'k': 249 /* 250 * This used to be... 251 * _conv(t->tm_hour % 12 ? 252 * t->tm_hour % 12 : 12, 2, ' '); 253 * ...and has been changed to the below to 254 * match SunOS 4.1.1 and Arnold Robbins' 255 * strftime version 3.0. That is, "%k" and 256 * "%l" have been swapped. 257 * (ado, 1993-05-24) 258 */ 259 pt = _conv(t->tm_hour, fmt_padding[PAD_FMT_SHMS][PadIndex], 260 pt, ptlim, loc); 261 continue; 262 #ifdef KITCHEN_SINK 263 case 'K': 264 /* 265 ** After all this time, still unclaimed! 266 */ 267 pt = _add("kitchen sink", pt, ptlim); 268 continue; 269 #endif /* defined KITCHEN_SINK */ 270 case 'l': 271 /* 272 * This used to be... 273 * _conv(t->tm_hour, 2, ' '); 274 * ...and has been changed to the below to 275 * match SunOS 4.1.1 and Arnold Robbin's 276 * strftime version 3.0. That is, "%k" and 277 * "%l" have been swapped. 278 * (ado, 1993-05-24) 279 */ 280 pt = _conv((t->tm_hour % 12) ? 281 (t->tm_hour % 12) : 12, 282 fmt_padding[PAD_FMT_SHMS][PadIndex], 283 pt, ptlim, loc); 284 continue; 285 case 'M': 286 pt = _conv(t->tm_min, fmt_padding[PAD_FMT_HMS][PadIndex], 287 pt, ptlim, loc); 288 continue; 289 case 'm': 290 pt = _conv(t->tm_mon + 1, 291 fmt_padding[PAD_FMT_MONTH][PadIndex], 292 pt, ptlim, loc); 293 continue; 294 case 'n': 295 pt = _add("\n", pt, ptlim); 296 continue; 297 case 'p': 298 pt = _add((t->tm_hour >= (HOURSPERDAY / 2)) ? 299 tptr->pm : tptr->am, 300 pt, ptlim); 301 continue; 302 case 'R': 303 pt = _fmt("%H:%M", t, pt, ptlim, warnp, loc); 304 continue; 305 case 'r': 306 pt = _fmt(tptr->ampm_fmt, t, pt, ptlim, 307 warnp, loc); 308 continue; 309 case 'S': 310 pt = _conv(t->tm_sec, fmt_padding[PAD_FMT_HMS][PadIndex], 311 pt, ptlim, loc); 312 continue; 313 case 's': 314 { 315 struct tm tm; 316 char buf[INT_STRLEN_MAXIMUM( 317 time_t) + 1]; 318 time_t mkt; 319 320 tm = *t; 321 mkt = mktime(&tm); 322 if (TYPE_SIGNED(time_t)) 323 (void) sprintf_l(buf, loc, "%ld", 324 (long) mkt); 325 else (void) sprintf_l(buf, loc, "%lu", 326 (unsigned long) mkt); 327 pt = _add(buf, pt, ptlim); 328 } 329 continue; 330 case 'T': 331 pt = _fmt("%H:%M:%S", t, pt, ptlim, warnp, loc); 332 continue; 333 case 't': 334 pt = _add("\t", pt, ptlim); 335 continue; 336 case 'U': 337 pt = _conv((t->tm_yday + DAYSPERWEEK - 338 t->tm_wday) / DAYSPERWEEK, 339 fmt_padding[PAD_FMT_WEEKOFYEAR][PadIndex], 340 pt, ptlim, loc); 341 continue; 342 case 'u': 343 /* 344 * From Arnold Robbins' strftime version 3.0: 345 * "ISO 8601: Weekday as a decimal number 346 * [1 (Monday) - 7]" 347 * (ado, 1993-05-24) 348 */ 349 pt = _conv((t->tm_wday == 0) ? 350 DAYSPERWEEK : t->tm_wday, 351 "%d", pt, ptlim, loc); 352 continue; 353 case 'V': /* ISO 8601 week number */ 354 case 'G': /* ISO 8601 year (four digits) */ 355 case 'g': /* ISO 8601 year (two digits) */ 356 /* 357 * From Arnold Robbins' strftime version 3.0: "the week number of the 358 * year (the first Monday as the first day of week 1) as a decimal number 359 * (01-53)." 360 * (ado, 1993-05-24) 361 * 362 * From "http://www.ft.uni-erlangen.de/~mskuhn/iso-time.html" by Markus Kuhn: 363 * "Week 01 of a year is per definition the first week which has the 364 * Thursday in this year, which is equivalent to the week which contains 365 * the fourth day of January. In other words, the first week of a new year 366 * is the week which has the majority of its days in the new year. Week 01 367 * might also contain days from the previous year and the week before week 368 * 01 of a year is the last week (52 or 53) of the previous year even if 369 * it contains days from the new year. A week starts with Monday (day 1) 370 * and ends with Sunday (day 7). For example, the first week of the year 371 * 1997 lasts from 1996-12-30 to 1997-01-05..." 372 * (ado, 1996-01-02) 373 */ 374 { 375 int year; 376 int base; 377 int yday; 378 int wday; 379 int w; 380 381 year = t->tm_year; 382 base = TM_YEAR_BASE; 383 yday = t->tm_yday; 384 wday = t->tm_wday; 385 for ( ; ; ) { 386 int len; 387 int bot; 388 int top; 389 390 len = isleap_sum(year, base) ? 391 DAYSPERLYEAR : 392 DAYSPERNYEAR; 393 /* 394 * What yday (-3 ... 3) does 395 * the ISO year begin on? 396 */ 397 bot = ((yday + 11 - wday) % 398 DAYSPERWEEK) - 3; 399 /* 400 * What yday does the NEXT 401 * ISO year begin on? 402 */ 403 top = bot - 404 (len % DAYSPERWEEK); 405 if (top < -3) 406 top += DAYSPERWEEK; 407 top += len; 408 if (yday >= top) { 409 ++base; 410 w = 1; 411 break; 412 } 413 if (yday >= bot) { 414 w = 1 + ((yday - bot) / 415 DAYSPERWEEK); 416 break; 417 } 418 --base; 419 yday += isleap_sum(year, base) ? 420 DAYSPERLYEAR : 421 DAYSPERNYEAR; 422 } 423 #ifdef XPG4_1994_04_09 424 if ((w == 52 && 425 t->tm_mon == TM_JANUARY) || 426 (w == 1 && 427 t->tm_mon == TM_DECEMBER)) 428 w = 53; 429 #endif /* defined XPG4_1994_04_09 */ 430 if (*format == 'V') 431 pt = _conv(w, fmt_padding[PAD_FMT_WEEKOFYEAR][PadIndex], 432 pt, ptlim, loc); 433 else if (*format == 'g') { 434 *warnp = IN_ALL; 435 pt = _yconv(year, base, 0, 1, 436 pt, ptlim, loc); 437 } else pt = _yconv(year, base, 1, 1, 438 pt, ptlim, loc); 439 } 440 continue; 441 case 'v': 442 /* 443 * From Arnold Robbins' strftime version 3.0: 444 * "date as dd-bbb-YYYY" 445 * (ado, 1993-05-24) 446 */ 447 pt = _fmt("%e-%b-%Y", t, pt, ptlim, warnp, loc); 448 continue; 449 case 'W': 450 pt = _conv((t->tm_yday + DAYSPERWEEK - 451 (t->tm_wday ? 452 (t->tm_wday - 1) : 453 (DAYSPERWEEK - 1))) / DAYSPERWEEK, 454 fmt_padding[PAD_FMT_WEEKOFYEAR][PadIndex], 455 pt, ptlim, loc); 456 continue; 457 case 'w': 458 pt = _conv(t->tm_wday, "%d", pt, ptlim, loc); 459 continue; 460 case 'X': 461 pt = _fmt(tptr->X_fmt, t, pt, ptlim, warnp, loc); 462 continue; 463 case 'x': 464 { 465 int warn2 = IN_SOME; 466 467 pt = _fmt(tptr->x_fmt, t, pt, ptlim, &warn2, loc); 468 if (warn2 == IN_ALL) 469 warn2 = IN_THIS; 470 if (warn2 > *warnp) 471 *warnp = warn2; 472 } 473 continue; 474 case 'y': 475 *warnp = IN_ALL; 476 pt = _yconv(t->tm_year, TM_YEAR_BASE, 0, 1, 477 pt, ptlim, loc); 478 continue; 479 case 'Y': 480 pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 1, 481 pt, ptlim, loc); 482 continue; 483 case 'Z': 484 #ifdef TM_ZONE 485 if (t->TM_ZONE != NULL) 486 pt = _add(t->TM_ZONE, pt, ptlim); 487 else 488 #endif /* defined TM_ZONE */ 489 if (t->tm_isdst >= 0) 490 pt = _add(tzname[t->tm_isdst != 0], 491 pt, ptlim); 492 /* 493 * C99 says that %Z must be replaced by the 494 * empty string if the time zone is not 495 * determinable. 496 */ 497 continue; 498 case 'z': 499 { 500 int diff; 501 char const * sign; 502 503 if (t->tm_isdst < 0) 504 continue; 505 #ifdef TM_GMTOFF 506 diff = t->TM_GMTOFF; 507 #else /* !defined TM_GMTOFF */ 508 /* 509 * C99 says that the UTC offset must 510 * be computed by looking only at 511 * tm_isdst. This requirement is 512 * incorrect, since it means the code 513 * must rely on magic (in this case 514 * altzone and timezone), and the 515 * magic might not have the correct 516 * offset. Doing things correctly is 517 * tricky and requires disobeying C99; 518 * see GNU C strftime for details. 519 * For now, punt and conform to the 520 * standard, even though it's incorrect. 521 * 522 * C99 says that %z must be replaced by the 523 * empty string if the time zone is not 524 * determinable, so output nothing if the 525 * appropriate variables are not available. 526 */ 527 if (t->tm_isdst == 0) 528 #ifdef USG_COMPAT 529 diff = -timezone; 530 #else /* !defined USG_COMPAT */ 531 continue; 532 #endif /* !defined USG_COMPAT */ 533 else 534 #ifdef ALTZONE 535 diff = -altzone; 536 #else /* !defined ALTZONE */ 537 continue; 538 #endif /* !defined ALTZONE */ 539 #endif /* !defined TM_GMTOFF */ 540 if (diff < 0) { 541 sign = "-"; 542 diff = -diff; 543 } else 544 sign = "+"; 545 pt = _add(sign, pt, ptlim); 546 diff /= SECSPERMIN; 547 diff = (diff / MINSPERHOUR) * 100 + 548 (diff % MINSPERHOUR); 549 pt = _conv(diff, 550 fmt_padding[PAD_FMT_YEAR][PadIndex], 551 pt, ptlim, loc); 552 } 553 continue; 554 case '+': 555 pt = _fmt(tptr->date_fmt, t, pt, ptlim, 556 warnp, loc); 557 continue; 558 case '-': 559 if (PadIndex != PAD_DEFAULT) 560 break; 561 PadIndex = PAD_LESS; 562 goto label; 563 case '_': 564 if (PadIndex != PAD_DEFAULT) 565 break; 566 PadIndex = PAD_SPACE; 567 goto label; 568 case '0': 569 if (PadIndex != PAD_DEFAULT) 570 break; 571 PadIndex = PAD_ZERO; 572 goto label; 573 case '%': 574 /* 575 * X311J/88-090 (4.12.3.5): if conversion char is 576 * undefined, behavior is undefined. Print out the 577 * character itself as printf(3) also does. 578 */ 579 default: 580 break; 581 } 582 } 583 if (pt == ptlim) 584 break; 585 *pt++ = *format; 586 } 587 return (pt); 588 } 589 590 static char * 591 _conv(const int n, const char * const format, char * const pt, 592 const char * const ptlim, locale_t loc) 593 { 594 char buf[INT_STRLEN_MAXIMUM(int) + 1]; 595 596 (void) sprintf_l(buf, loc, format, n); 597 return _add(buf, pt, ptlim); 598 } 599 600 static char * 601 _add(const char *str, char *pt, const char * const ptlim) 602 { 603 while (pt < ptlim && (*pt = *str++) != '\0') 604 ++pt; 605 return (pt); 606 } 607 608 /* 609 * POSIX and the C Standard are unclear or inconsistent about 610 * what %C and %y do if the year is negative or exceeds 9999. 611 * Use the convention that %C concatenated with %y yields the 612 * same output as %Y, and that %Y contains at least 4 bytes, 613 * with more only if necessary. 614 */ 615 616 static char * 617 _yconv(const int a, const int b, const int convert_top, const int convert_yy, 618 char *pt, const char * const ptlim, locale_t loc) 619 { 620 register int lead; 621 register int trail; 622 623 #define DIVISOR 100 624 trail = a % DIVISOR + b % DIVISOR; 625 lead = a / DIVISOR + b / DIVISOR + trail / DIVISOR; 626 trail %= DIVISOR; 627 if (trail < 0 && lead > 0) { 628 trail += DIVISOR; 629 --lead; 630 } else if (lead < 0 && trail > 0) { 631 trail -= DIVISOR; 632 ++lead; 633 } 634 if (convert_top) { 635 if (lead == 0 && trail < 0) 636 pt = _add("-0", pt, ptlim); 637 else pt = _conv(lead, "%02d", pt, ptlim, loc); 638 } 639 if (convert_yy) 640 pt = _conv(((trail < 0) ? -trail : trail), "%02d", pt, 641 ptlim, loc); 642 return (pt); 643 } 644