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 *); 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 *); 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) fprintf_l(stderr, loc, "NULL strftime format "); 105 else (void) fprintf_l(stderr, loc, "strftime format \"%s\" ", 106 format); 107 (void) fprintf_l(stderr, loc, "yields only two digits of years in "); 108 if (warn == IN_SOME) 109 (void) fprintf_l(stderr, loc, "some locales"); 110 else if (warn == IN_THIS) 111 (void) fprintf_l(stderr, loc, "the current locale"); 112 else (void) fprintf_l(stderr, loc, "all locales"); 113 (void) fprintf_l(stderr, loc, "\n"); 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); 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, fmt_padding[PAD_FMT_DAYOFMONTH][PadIndex], 204 pt, ptlim); 205 continue; 206 case 'E': 207 if (Ealternative || Oalternative) 208 break; 209 Ealternative++; 210 goto label; 211 case 'O': 212 /* 213 * C99 locale modifiers. 214 * The sequences 215 * %Ec %EC %Ex %EX %Ey %EY 216 * %Od %oe %OH %OI %Om %OM 217 * %OS %Ou %OU %OV %Ow %OW %Oy 218 * are supposed to provide alternate 219 * representations. 220 * 221 * FreeBSD extension 222 * %OB 223 */ 224 if (Ealternative || Oalternative) 225 break; 226 Oalternative++; 227 goto label; 228 case 'e': 229 pt = _conv(t->tm_mday, 230 fmt_padding[PAD_FMT_SDAYOFMONTH][PadIndex], pt, ptlim); 231 continue; 232 case 'F': 233 pt = _fmt("%Y-%m-%d", t, pt, ptlim, warnp, loc); 234 continue; 235 case 'H': 236 pt = _conv(t->tm_hour, fmt_padding[PAD_FMT_HMS][PadIndex], 237 pt, ptlim); 238 continue; 239 case 'I': 240 pt = _conv((t->tm_hour % 12) ? 241 (t->tm_hour % 12) : 12, 242 fmt_padding[PAD_FMT_HMS][PadIndex], 243 pt, ptlim); 244 continue; 245 case 'j': 246 pt = _conv(t->tm_yday + 1, 247 fmt_padding[PAD_FMT_DAYOFYEAR][PadIndex], pt, ptlim); 248 continue; 249 case 'k': 250 /* 251 * This used to be... 252 * _conv(t->tm_hour % 12 ? 253 * t->tm_hour % 12 : 12, 2, ' '); 254 * ...and has been changed to the below to 255 * match SunOS 4.1.1 and Arnold Robbins' 256 * strftime version 3.0. That is, "%k" and 257 * "%l" have been swapped. 258 * (ado, 1993-05-24) 259 */ 260 pt = _conv(t->tm_hour, fmt_padding[PAD_FMT_SHMS][PadIndex], 261 pt, ptlim); 262 continue; 263 #ifdef KITCHEN_SINK 264 case 'K': 265 /* 266 ** After all this time, still unclaimed! 267 */ 268 pt = _add("kitchen sink", pt, ptlim); 269 continue; 270 #endif /* defined KITCHEN_SINK */ 271 case 'l': 272 /* 273 * This used to be... 274 * _conv(t->tm_hour, 2, ' '); 275 * ...and has been changed to the below to 276 * match SunOS 4.1.1 and Arnold Robbin's 277 * strftime version 3.0. That is, "%k" and 278 * "%l" have been swapped. 279 * (ado, 1993-05-24) 280 */ 281 pt = _conv((t->tm_hour % 12) ? 282 (t->tm_hour % 12) : 12, 283 fmt_padding[PAD_FMT_SHMS][PadIndex], 284 pt, ptlim); 285 continue; 286 case 'M': 287 pt = _conv(t->tm_min, fmt_padding[PAD_FMT_HMS][PadIndex], 288 pt, ptlim); 289 continue; 290 case 'm': 291 pt = _conv(t->tm_mon + 1, 292 fmt_padding[PAD_FMT_MONTH][PadIndex], 293 pt, ptlim); 294 continue; 295 case 'n': 296 pt = _add("\n", pt, ptlim); 297 continue; 298 case 'p': 299 pt = _add((t->tm_hour >= (HOURSPERDAY / 2)) ? 300 tptr->pm : tptr->am, 301 pt, ptlim); 302 continue; 303 case 'R': 304 pt = _fmt("%H:%M", t, pt, ptlim, warnp, loc); 305 continue; 306 case 'r': 307 pt = _fmt(tptr->ampm_fmt, t, pt, ptlim, 308 warnp, loc); 309 continue; 310 case 'S': 311 pt = _conv(t->tm_sec, fmt_padding[PAD_FMT_HMS][PadIndex], 312 pt, ptlim); 313 continue; 314 case 's': 315 { 316 struct tm tm; 317 char buf[INT_STRLEN_MAXIMUM( 318 time_t) + 1]; 319 time_t mkt; 320 321 tm = *t; 322 mkt = mktime(&tm); 323 if (TYPE_SIGNED(time_t)) 324 (void) sprintf(buf, "%ld", 325 (long) mkt); 326 else (void) sprintf(buf, "%lu", 327 (unsigned long) mkt); 328 pt = _add(buf, pt, ptlim); 329 } 330 continue; 331 case 'T': 332 pt = _fmt("%H:%M:%S", t, pt, ptlim, warnp, loc); 333 continue; 334 case 't': 335 pt = _add("\t", pt, ptlim); 336 continue; 337 case 'U': 338 pt = _conv((t->tm_yday + DAYSPERWEEK - 339 t->tm_wday) / DAYSPERWEEK, 340 fmt_padding[PAD_FMT_WEEKOFYEAR][PadIndex], pt, ptlim); 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); 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); 433 else if (*format == 'g') { 434 *warnp = IN_ALL; 435 pt = _yconv(year, base, 0, 1, 436 pt, ptlim); 437 } else pt = _yconv(year, base, 1, 1, 438 pt, ptlim); 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], pt, ptlim); 455 continue; 456 case 'w': 457 pt = _conv(t->tm_wday, "%d", pt, ptlim); 458 continue; 459 case 'X': 460 pt = _fmt(tptr->X_fmt, t, pt, ptlim, warnp, loc); 461 continue; 462 case 'x': 463 { 464 int warn2 = IN_SOME; 465 466 pt = _fmt(tptr->x_fmt, t, pt, ptlim, &warn2, loc); 467 if (warn2 == IN_ALL) 468 warn2 = IN_THIS; 469 if (warn2 > *warnp) 470 *warnp = warn2; 471 } 472 continue; 473 case 'y': 474 *warnp = IN_ALL; 475 pt = _yconv(t->tm_year, TM_YEAR_BASE, 0, 1, 476 pt, ptlim); 477 continue; 478 case 'Y': 479 pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 1, 480 pt, ptlim); 481 continue; 482 case 'Z': 483 #ifdef TM_ZONE 484 if (t->TM_ZONE != NULL) 485 pt = _add(t->TM_ZONE, pt, ptlim); 486 else 487 #endif /* defined TM_ZONE */ 488 if (t->tm_isdst >= 0) 489 pt = _add(tzname[t->tm_isdst != 0], 490 pt, ptlim); 491 /* 492 * C99 says that %Z must be replaced by the 493 * empty string if the time zone is not 494 * determinable. 495 */ 496 continue; 497 case 'z': 498 { 499 int diff; 500 char const * sign; 501 502 if (t->tm_isdst < 0) 503 continue; 504 #ifdef TM_GMTOFF 505 diff = t->TM_GMTOFF; 506 #else /* !defined TM_GMTOFF */ 507 /* 508 * C99 says that the UTC offset must 509 * be computed by looking only at 510 * tm_isdst. This requirement is 511 * incorrect, since it means the code 512 * must rely on magic (in this case 513 * altzone and timezone), and the 514 * magic might not have the correct 515 * offset. Doing things correctly is 516 * tricky and requires disobeying C99; 517 * see GNU C strftime for details. 518 * For now, punt and conform to the 519 * standard, even though it's incorrect. 520 * 521 * C99 says that %z must be replaced by the 522 * empty string if the time zone is not 523 * determinable, so output nothing if the 524 * appropriate variables are not available. 525 */ 526 if (t->tm_isdst == 0) 527 #ifdef USG_COMPAT 528 diff = -timezone; 529 #else /* !defined USG_COMPAT */ 530 continue; 531 #endif /* !defined USG_COMPAT */ 532 else 533 #ifdef ALTZONE 534 diff = -altzone; 535 #else /* !defined ALTZONE */ 536 continue; 537 #endif /* !defined ALTZONE */ 538 #endif /* !defined TM_GMTOFF */ 539 if (diff < 0) { 540 sign = "-"; 541 diff = -diff; 542 } else 543 sign = "+"; 544 pt = _add(sign, pt, ptlim); 545 diff /= SECSPERMIN; 546 diff = (diff / MINSPERHOUR) * 100 + 547 (diff % MINSPERHOUR); 548 pt = _conv(diff, 549 fmt_padding[PAD_FMT_YEAR][PadIndex], pt, ptlim); 550 } 551 continue; 552 case '+': 553 pt = _fmt(tptr->date_fmt, t, pt, ptlim, 554 warnp, loc); 555 continue; 556 case '-': 557 if (PadIndex != PAD_DEFAULT) 558 break; 559 PadIndex = PAD_LESS; 560 goto label; 561 case '_': 562 if (PadIndex != PAD_DEFAULT) 563 break; 564 PadIndex = PAD_SPACE; 565 goto label; 566 case '0': 567 if (PadIndex != PAD_DEFAULT) 568 break; 569 PadIndex = PAD_ZERO; 570 goto label; 571 case '%': 572 /* 573 * X311J/88-090 (4.12.3.5): if conversion char is 574 * undefined, behavior is undefined. Print out the 575 * character itself as printf(3) also does. 576 */ 577 default: 578 break; 579 } 580 } 581 if (pt == ptlim) 582 break; 583 *pt++ = *format; 584 } 585 return (pt); 586 } 587 588 static char * 589 _conv(n, format, pt, ptlim) 590 const int n; 591 const char * const format; 592 char * const pt; 593 const char * const ptlim; 594 { 595 char buf[INT_STRLEN_MAXIMUM(int) + 1]; 596 597 (void) sprintf(buf, format, n); 598 return _add(buf, pt, ptlim); 599 } 600 601 static char * 602 _add(str, pt, ptlim) 603 const char * str; 604 char * pt; 605 const char * const ptlim; 606 { 607 while (pt < ptlim && (*pt = *str++) != '\0') 608 ++pt; 609 return (pt); 610 } 611 612 /* 613 * POSIX and the C Standard are unclear or inconsistent about 614 * what %C and %y do if the year is negative or exceeds 9999. 615 * Use the convention that %C concatenated with %y yields the 616 * same output as %Y, and that %Y contains at least 4 bytes, 617 * with more only if necessary. 618 */ 619 620 static char * 621 _yconv(a, b, convert_top, convert_yy, pt, ptlim) 622 const int a; 623 const int b; 624 const int convert_top; 625 const int convert_yy; 626 char * pt; 627 const char * const ptlim; 628 { 629 register int lead; 630 register int trail; 631 632 #define DIVISOR 100 633 trail = a % DIVISOR + b % DIVISOR; 634 lead = a / DIVISOR + b / DIVISOR + trail / DIVISOR; 635 trail %= DIVISOR; 636 if (trail < 0 && lead > 0) { 637 trail += DIVISOR; 638 --lead; 639 } else if (lead < 0 && trail > 0) { 640 trail -= DIVISOR; 641 ++lead; 642 } 643 if (convert_top) { 644 if (lead == 0 && trail < 0) 645 pt = _add("-0", pt, ptlim); 646 else pt = _conv(lead, "%02d", pt, ptlim); 647 } 648 if (convert_yy) 649 pt = _conv(((trail < 0) ? -trail : trail), "%02d", pt, ptlim); 650 return (pt); 651 } 652