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], pt, ptlim); 243 continue; 244 case 'j': 245 pt = _conv(t->tm_yday + 1, 246 fmt_padding[PAD_FMT_DAYOFYEAR][PadIndex], pt, ptlim); 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); 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], pt, ptlim); 283 continue; 284 case 'M': 285 pt = _conv(t->tm_min, fmt_padding[PAD_FMT_HMS][PadIndex], 286 pt, ptlim); 287 continue; 288 case 'm': 289 pt = _conv(t->tm_mon + 1, 290 fmt_padding[PAD_FMT_MONTH][PadIndex], pt, ptlim); 291 continue; 292 case 'n': 293 pt = _add("\n", pt, ptlim); 294 continue; 295 case 'p': 296 pt = _add((t->tm_hour >= (HOURSPERDAY / 2)) ? 297 tptr->pm : 298 tptr->am, 299 pt, ptlim); 300 continue; 301 case 'R': 302 pt = _fmt("%H:%M", t, pt, ptlim, warnp, loc); 303 continue; 304 case 'r': 305 pt = _fmt(tptr->ampm_fmt, t, pt, ptlim, 306 warnp, loc); 307 continue; 308 case 'S': 309 pt = _conv(t->tm_sec, fmt_padding[PAD_FMT_HMS][PadIndex], 310 pt, ptlim); 311 continue; 312 case 's': 313 { 314 struct tm tm; 315 char buf[INT_STRLEN_MAXIMUM( 316 time_t) + 1]; 317 time_t mkt; 318 319 tm = *t; 320 mkt = mktime(&tm); 321 if (TYPE_SIGNED(time_t)) 322 (void) sprintf(buf, "%ld", 323 (long) mkt); 324 else (void) sprintf(buf, "%lu", 325 (unsigned long) mkt); 326 pt = _add(buf, pt, ptlim); 327 } 328 continue; 329 case 'T': 330 pt = _fmt("%H:%M:%S", t, pt, ptlim, warnp, loc); 331 continue; 332 case 't': 333 pt = _add("\t", pt, ptlim); 334 continue; 335 case 'U': 336 pt = _conv((t->tm_yday + DAYSPERWEEK - 337 t->tm_wday) / DAYSPERWEEK, 338 fmt_padding[PAD_FMT_WEEKOFYEAR][PadIndex], pt, ptlim); 339 continue; 340 case 'u': 341 /* 342 ** From Arnold Robbins' strftime version 3.0: 343 ** "ISO 8601: Weekday as a decimal number 344 ** [1 (Monday) - 7]" 345 ** (ado, 1993-05-24) 346 */ 347 pt = _conv((t->tm_wday == 0) ? 348 DAYSPERWEEK : t->tm_wday, 349 "%d", pt, ptlim); 350 continue; 351 case 'V': /* ISO 8601 week number */ 352 case 'G': /* ISO 8601 year (four digits) */ 353 case 'g': /* ISO 8601 year (two digits) */ 354 /* 355 ** From Arnold Robbins' strftime version 3.0: "the week number of the 356 ** year (the first Monday as the first day of week 1) as a decimal number 357 ** (01-53)." 358 ** (ado, 1993-05-24) 359 ** 360 ** From "http://www.ft.uni-erlangen.de/~mskuhn/iso-time.html" by Markus Kuhn: 361 ** "Week 01 of a year is per definition the first week which has the 362 ** Thursday in this year, which is equivalent to the week which contains 363 ** the fourth day of January. In other words, the first week of a new year 364 ** is the week which has the majority of its days in the new year. Week 01 365 ** might also contain days from the previous year and the week before week 366 ** 01 of a year is the last week (52 or 53) of the previous year even if 367 ** it contains days from the new year. A week starts with Monday (day 1) 368 ** and ends with Sunday (day 7). For example, the first week of the year 369 ** 1997 lasts from 1996-12-30 to 1997-01-05..." 370 ** (ado, 1996-01-02) 371 */ 372 { 373 int year; 374 int base; 375 int yday; 376 int wday; 377 int w; 378 379 year = t->tm_year; 380 base = TM_YEAR_BASE; 381 yday = t->tm_yday; 382 wday = t->tm_wday; 383 for ( ; ; ) { 384 int len; 385 int bot; 386 int top; 387 388 len = isleap_sum(year, base) ? 389 DAYSPERLYEAR : 390 DAYSPERNYEAR; 391 /* 392 ** What yday (-3 ... 3) does 393 ** the ISO year begin on? 394 */ 395 bot = ((yday + 11 - wday) % 396 DAYSPERWEEK) - 3; 397 /* 398 ** What yday does the NEXT 399 ** ISO year begin on? 400 */ 401 top = bot - 402 (len % DAYSPERWEEK); 403 if (top < -3) 404 top += DAYSPERWEEK; 405 top += len; 406 if (yday >= top) { 407 ++base; 408 w = 1; 409 break; 410 } 411 if (yday >= bot) { 412 w = 1 + ((yday - bot) / 413 DAYSPERWEEK); 414 break; 415 } 416 --base; 417 yday += isleap_sum(year, base) ? 418 DAYSPERLYEAR : 419 DAYSPERNYEAR; 420 } 421 #ifdef XPG4_1994_04_09 422 if ((w == 52 && 423 t->tm_mon == TM_JANUARY) || 424 (w == 1 && 425 t->tm_mon == TM_DECEMBER)) 426 w = 53; 427 #endif /* defined XPG4_1994_04_09 */ 428 if (*format == 'V') 429 pt = _conv(w, fmt_padding[PAD_FMT_WEEKOFYEAR][PadIndex], 430 pt, ptlim); 431 else if (*format == 'g') { 432 *warnp = IN_ALL; 433 pt = _yconv(year, base, 0, 1, 434 pt, ptlim); 435 } else pt = _yconv(year, base, 1, 1, 436 pt, ptlim); 437 } 438 continue; 439 case 'v': 440 /* 441 ** From Arnold Robbins' strftime version 3.0: 442 ** "date as dd-bbb-YYYY" 443 ** (ado, 1993-05-24) 444 */ 445 pt = _fmt("%e-%b-%Y", t, pt, ptlim, warnp, loc); 446 continue; 447 case 'W': 448 pt = _conv((t->tm_yday + DAYSPERWEEK - 449 (t->tm_wday ? 450 (t->tm_wday - 1) : 451 (DAYSPERWEEK - 1))) / DAYSPERWEEK, 452 fmt_padding[PAD_FMT_WEEKOFYEAR][PadIndex], pt, ptlim); 453 continue; 454 case 'w': 455 pt = _conv(t->tm_wday, "%d", pt, ptlim); 456 continue; 457 case 'X': 458 pt = _fmt(tptr->X_fmt, t, pt, ptlim, warnp, loc); 459 continue; 460 case 'x': 461 { 462 int warn2 = IN_SOME; 463 464 pt = _fmt(tptr->x_fmt, t, pt, ptlim, &warn2, loc); 465 if (warn2 == IN_ALL) 466 warn2 = IN_THIS; 467 if (warn2 > *warnp) 468 *warnp = warn2; 469 } 470 continue; 471 case 'y': 472 *warnp = IN_ALL; 473 pt = _yconv(t->tm_year, TM_YEAR_BASE, 0, 1, 474 pt, ptlim); 475 continue; 476 case 'Y': 477 pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 1, 478 pt, ptlim); 479 continue; 480 case 'Z': 481 #ifdef TM_ZONE 482 if (t->TM_ZONE != NULL) 483 pt = _add(t->TM_ZONE, pt, ptlim); 484 else 485 #endif /* defined TM_ZONE */ 486 if (t->tm_isdst >= 0) 487 pt = _add(tzname[t->tm_isdst != 0], 488 pt, ptlim); 489 /* 490 ** C99 says that %Z must be replaced by the 491 ** empty string if the time zone is not 492 ** determinable. 493 */ 494 continue; 495 case 'z': 496 { 497 int diff; 498 char const * sign; 499 500 if (t->tm_isdst < 0) 501 continue; 502 #ifdef TM_GMTOFF 503 diff = t->TM_GMTOFF; 504 #else /* !defined TM_GMTOFF */ 505 /* 506 ** C99 says that the UTC offset must 507 ** be computed by looking only at 508 ** tm_isdst. This requirement is 509 ** incorrect, since it means the code 510 ** must rely on magic (in this case 511 ** altzone and timezone), and the 512 ** magic might not have the correct 513 ** offset. Doing things correctly is 514 ** tricky and requires disobeying C99; 515 ** see GNU C strftime for details. 516 ** For now, punt and conform to the 517 ** standard, even though it's incorrect. 518 ** 519 ** C99 says that %z must be replaced by the 520 ** empty string if the time zone is not 521 ** determinable, so output nothing if the 522 ** appropriate variables are not available. 523 */ 524 if (t->tm_isdst == 0) 525 #ifdef USG_COMPAT 526 diff = -timezone; 527 #else /* !defined USG_COMPAT */ 528 continue; 529 #endif /* !defined USG_COMPAT */ 530 else 531 #ifdef ALTZONE 532 diff = -altzone; 533 #else /* !defined ALTZONE */ 534 continue; 535 #endif /* !defined ALTZONE */ 536 #endif /* !defined TM_GMTOFF */ 537 if (diff < 0) { 538 sign = "-"; 539 diff = -diff; 540 } else sign = "+"; 541 pt = _add(sign, pt, ptlim); 542 diff /= SECSPERMIN; 543 diff = (diff / MINSPERHOUR) * 100 + 544 (diff % MINSPERHOUR); 545 pt = _conv(diff, 546 fmt_padding[PAD_FMT_YEAR][PadIndex], pt, ptlim); 547 } 548 continue; 549 case '+': 550 pt = _fmt(tptr->date_fmt, t, pt, ptlim, 551 warnp, loc); 552 continue; 553 case '-': 554 if (PadIndex != PAD_DEFAULT) 555 break; 556 PadIndex = PAD_LESS; 557 goto label; 558 case '_': 559 if (PadIndex != PAD_DEFAULT) 560 break; 561 PadIndex = PAD_SPACE; 562 goto label; 563 case '0': 564 if (PadIndex != PAD_DEFAULT) 565 break; 566 PadIndex = PAD_ZERO; 567 goto label; 568 case '%': 569 /* 570 ** X311J/88-090 (4.12.3.5): if conversion char is 571 ** undefined, behavior is undefined. Print out the 572 ** character itself as printf(3) also does. 573 */ 574 default: 575 break; 576 } 577 } 578 if (pt == ptlim) 579 break; 580 *pt++ = *format; 581 } 582 return pt; 583 } 584 585 static char * 586 _conv(n, format, pt, ptlim) 587 const int n; 588 const char * const format; 589 char * const pt; 590 const char * const ptlim; 591 { 592 char buf[INT_STRLEN_MAXIMUM(int) + 1]; 593 594 (void) sprintf(buf, format, n); 595 return _add(buf, pt, ptlim); 596 } 597 598 static char * 599 _add(str, pt, ptlim) 600 const char * str; 601 char * pt; 602 const char * const ptlim; 603 { 604 while (pt < ptlim && (*pt = *str++) != '\0') 605 ++pt; 606 return pt; 607 } 608 609 /* 610 ** POSIX and the C Standard are unclear or inconsistent about 611 ** what %C and %y do if the year is negative or exceeds 9999. 612 ** Use the convention that %C concatenated with %y yields the 613 ** same output as %Y, and that %Y contains at least 4 bytes, 614 ** with more only if necessary. 615 */ 616 617 static char * 618 _yconv(a, b, convert_top, convert_yy, pt, ptlim) 619 const int a; 620 const int b; 621 const int convert_top; 622 const int convert_yy; 623 char * pt; 624 const char * const ptlim; 625 { 626 register int lead; 627 register int trail; 628 629 #define DIVISOR 100 630 trail = a % DIVISOR + b % DIVISOR; 631 lead = a / DIVISOR + b / DIVISOR + trail / DIVISOR; 632 trail %= DIVISOR; 633 if (trail < 0 && lead > 0) { 634 trail += DIVISOR; 635 --lead; 636 } else if (lead < 0 && trail > 0) { 637 trail -= DIVISOR; 638 ++lead; 639 } 640 if (convert_top) { 641 if (lead == 0 && trail < 0) 642 pt = _add("-0", pt, ptlim); 643 else pt = _conv(lead, "%02d", pt, ptlim); 644 } 645 if (convert_yy) 646 pt = _conv(((trail < 0) ? -trail : trail), "%02d", pt, ptlim); 647 return pt; 648 } 649