1 /* $NetBSD: strftime.c,v 1.19 2009/01/11 02:46:30 christos Exp $ */ 2 3 #include <sys/cdefs.h> 4 #if defined(LIBC_SCCS) && !defined(lint) 5 #if 0 6 static char elsieid[] = "@(#)strftime.c 7.64"; 7 #else 8 __RCSID("$NetBSD: strftime.c,v 1.19 2009/01/11 02:46:30 christos Exp $"); 9 #endif 10 #endif /* LIBC_SCCS and not lint */ 11 12 #include "namespace.h" 13 14 /* 15 ** Based on the UCB version with the ID appearing below. 16 ** This is ANSIish only when "multibyte character == plain character". 17 */ 18 19 #include "private.h" 20 21 /* 22 ** We don't use these extensions in strftime operation even when 23 ** supported by the local tzcode configuration. A strictly 24 ** conforming C application may leave them in undefined state. 25 */ 26 27 #ifdef _LIBC 28 #undef TM_ZONE 29 #undef TM_GMTOFF 30 #endif 31 32 /* 33 ** Copyright (c) 1989, 1993 34 ** The Regents of the University of California. All rights reserved. 35 ** 36 ** Redistribution and use in source and binary forms, with or without 37 ** modification, are permitted provided that the following conditions 38 ** are met: 39 ** 1. Redistributions of source code must retain the above copyright 40 ** notice, this list of conditions and the following disclaimer. 41 ** 2. Redistributions in binary form must reproduce the above copyright 42 ** notice, this list of conditions and the following disclaimer in the 43 ** documentation and/or other materials provided with the distribution. 44 ** 3. All advertising materials mentioning features or use of this software 45 ** must display the following acknowledgement: 46 ** This product includes software developed by the University of 47 ** California, Berkeley and its contributors. 48 ** 4. Neither the name of the University nor the names of its contributors 49 ** may be used to endorse or promote products derived from this software 50 ** without specific prior written permission. 51 ** 52 ** THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 53 ** ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 54 ** IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 55 ** ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 56 ** FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 57 ** DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 58 ** OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 59 ** HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 60 ** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 61 ** OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 62 ** SUCH DAMAGE. 63 */ 64 65 #ifndef LIBC_SCCS 66 #ifndef lint 67 static const char sccsid[] = "@(#)strftime.c 5.4 (Berkeley) 3/14/89"; 68 #endif /* !defined lint */ 69 #endif /* !defined LIBC_SCCS */ 70 71 #include "tzfile.h" 72 #include "fcntl.h" 73 #include "locale.h" 74 75 #include "sys/localedef.h" 76 #define Locale _CurrentTimeLocale 77 78 static char * _add P((const char *, char *, const char *)); 79 static char * _conv P((int, const char *, char *, const char *)); 80 static char * _fmt P((const char *, const struct tm *, char *, const char *, int *)); 81 82 #define NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU 83 84 #ifndef YEAR_2000_NAME 85 #define YEAR_2000_NAME "CHECK_STRFTIME_FORMATS_FOR_TWO_DIGIT_YEARS" 86 #endif /* !defined YEAR_2000_NAME */ 87 88 89 #define IN_NONE 0 90 #define IN_SOME 1 91 #define IN_THIS 2 92 #define IN_ALL 3 93 94 size_t 95 strftime(s, maxsize, format, t) 96 char * const s; 97 const size_t maxsize; 98 const char * const format; 99 const struct tm * const t; 100 { 101 char * p; 102 int warn; 103 104 tzset(); 105 warn = IN_NONE; 106 p = _fmt(((format == NULL) ? "%c" : format), t, s, s + maxsize, &warn); 107 #ifndef NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU 108 if (warn != IN_NONE && getenv(YEAR_2000_NAME) != NULL) { 109 (void) fprintf(stderr, "\n"); 110 if (format == NULL) 111 (void) fprintf(stderr, "NULL strftime format "); 112 else (void) fprintf(stderr, "strftime format \"%s\" ", 113 format); 114 (void) fprintf(stderr, "yields only two digits of years in "); 115 if (warn == IN_SOME) 116 (void) fprintf(stderr, "some locales"); 117 else if (warn == IN_THIS) 118 (void) fprintf(stderr, "the current locale"); 119 else (void) fprintf(stderr, "all locales"); 120 (void) fprintf(stderr, "\n"); 121 } 122 #endif /* !defined NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU */ 123 if (p == s + maxsize) 124 return 0; 125 *p = '\0'; 126 return p - s; 127 } 128 129 static char * 130 _fmt(format, t, pt, ptlim, warnp) 131 const char * format; 132 const struct tm * const t; 133 char * pt; 134 const char * const ptlim; 135 int * warnp; 136 { 137 for ( ; *format; ++format) { 138 if (*format == '%') { 139 label: 140 switch (*++format) { 141 case '\0': 142 --format; 143 break; 144 case 'A': 145 pt = _add((t->tm_wday < 0 || 146 t->tm_wday >= DAYSPERWEEK) ? 147 "?" : Locale->day[t->tm_wday], 148 pt, ptlim); 149 continue; 150 case 'a': 151 pt = _add((t->tm_wday < 0 || 152 t->tm_wday >= DAYSPERWEEK) ? 153 "?" : Locale->abday[t->tm_wday], 154 pt, ptlim); 155 continue; 156 case 'B': 157 pt = _add((t->tm_mon < 0 || 158 t->tm_mon >= MONSPERYEAR) ? 159 "?" : Locale->mon[t->tm_mon], 160 pt, ptlim); 161 continue; 162 case 'b': 163 case 'h': 164 pt = _add((t->tm_mon < 0 || 165 t->tm_mon >= MONSPERYEAR) ? 166 "?" : Locale->abmon[t->tm_mon], 167 pt, ptlim); 168 continue; 169 case 'C': 170 /* 171 ** %C used to do a... 172 ** _fmt("%a %b %e %X %Y", t); 173 ** ...whereas now POSIX 1003.2 calls for 174 ** something completely different. 175 ** (ado, 1993-05-24) 176 */ 177 pt = _conv((t->tm_year + TM_YEAR_BASE) / 100, 178 "%02d", pt, ptlim); 179 continue; 180 case 'c': 181 { 182 int warn2 = IN_SOME; 183 184 pt = _fmt(Locale->d_t_fmt, t, pt, ptlim, &warn2); 185 if (warn2 == IN_ALL) 186 warn2 = IN_THIS; 187 if (warn2 > *warnp) 188 *warnp = warn2; 189 } 190 continue; 191 case 'D': 192 pt = _fmt("%m/%d/%y", t, pt, ptlim, warnp); 193 continue; 194 case 'd': 195 pt = _conv(t->tm_mday, "%02d", pt, ptlim); 196 continue; 197 case 'E': 198 case 'O': 199 /* 200 ** C99 locale modifiers. 201 ** The sequences 202 ** %Ec %EC %Ex %EX %Ey %EY 203 ** %Od %oe %OH %OI %Om %OM 204 ** %OS %Ou %OU %OV %Ow %OW %Oy 205 ** are supposed to provide alternate 206 ** representations. 207 */ 208 goto label; 209 case 'e': 210 pt = _conv(t->tm_mday, "%2d", pt, ptlim); 211 continue; 212 case 'F': 213 pt = _fmt("%Y-%m-%d", t, pt, ptlim, warnp); 214 continue; 215 case 'H': 216 pt = _conv(t->tm_hour, "%02d", pt, ptlim); 217 continue; 218 case 'I': 219 pt = _conv((t->tm_hour % 12) ? 220 (t->tm_hour % 12) : 12, 221 "%02d", pt, ptlim); 222 continue; 223 case 'j': 224 pt = _conv(t->tm_yday + 1, "%03d", pt, ptlim); 225 continue; 226 case 'k': 227 /* 228 ** This used to be... 229 ** _conv(t->tm_hour % 12 ? 230 ** t->tm_hour % 12 : 12, 2, ' '); 231 ** ...and has been changed to the below to 232 ** match SunOS 4.1.1 and Arnold Robbins' 233 ** strftime version 3.0. That is, "%k" and 234 ** "%l" have been swapped. 235 ** (ado, 1993-05-24) 236 */ 237 pt = _conv(t->tm_hour, "%2d", pt, ptlim); 238 continue; 239 #ifdef KITCHEN_SINK 240 case 'K': 241 /* 242 ** After all this time, still unclaimed! 243 */ 244 pt = _add("kitchen sink", pt, ptlim); 245 continue; 246 #endif /* defined KITCHEN_SINK */ 247 case 'l': 248 /* 249 ** This used to be... 250 ** _conv(t->tm_hour, 2, ' '); 251 ** ...and has been changed to the below to 252 ** match SunOS 4.1.1 and Arnold Robbin's 253 ** strftime version 3.0. That is, "%k" and 254 ** "%l" have been swapped. 255 ** (ado, 1993-05-24) 256 */ 257 pt = _conv((t->tm_hour % 12) ? 258 (t->tm_hour % 12) : 12, 259 "%2d", pt, ptlim); 260 continue; 261 case 'M': 262 pt = _conv(t->tm_min, "%02d", pt, ptlim); 263 continue; 264 case 'm': 265 pt = _conv(t->tm_mon + 1, "%02d", pt, ptlim); 266 continue; 267 case 'n': 268 pt = _add("\n", pt, ptlim); 269 continue; 270 case 'p': 271 pt = _add((t->tm_hour >= (HOURSPERDAY / 2)) ? 272 Locale->am_pm[1] : 273 Locale->am_pm[0], 274 pt, ptlim); 275 continue; 276 case 'R': 277 pt = _fmt("%H:%M", t, pt, ptlim, warnp); 278 continue; 279 case 'r': 280 pt = _fmt(Locale->t_fmt_ampm, t, pt, ptlim, 281 warnp); 282 continue; 283 case 'S': 284 pt = _conv(t->tm_sec, "%02d", pt, ptlim); 285 continue; 286 case 's': 287 { 288 struct tm tm; 289 char buf[INT_STRLEN_MAXIMUM( 290 time_t) + 1]; 291 time_t mkt; 292 293 tm = *t; 294 mkt = mktime(&tm); 295 /* CONSTCOND */ 296 if (TYPE_SIGNED(time_t)) 297 (void) snprintf(buf, sizeof(buf), 298 "%lld", (long long) mkt); 299 else (void) snprintf(buf, sizeof(buf), 300 "%llu", (unsigned long long) 301 mkt); 302 pt = _add(buf, pt, ptlim); 303 } 304 continue; 305 case 'T': 306 pt = _fmt("%H:%M:%S", t, pt, ptlim, warnp); 307 continue; 308 case 't': 309 pt = _add("\t", pt, ptlim); 310 continue; 311 case 'U': 312 pt = _conv((t->tm_yday + DAYSPERWEEK - 313 t->tm_wday) / DAYSPERWEEK, 314 "%02d", pt, ptlim); 315 continue; 316 case 'u': 317 /* 318 ** From Arnold Robbins' strftime version 3.0: 319 ** "ISO 8601: Weekday as a decimal number 320 ** [1 (Monday) - 7]" 321 ** (ado, 1993-05-24) 322 */ 323 pt = _conv((t->tm_wday == 0) ? 324 DAYSPERWEEK : t->tm_wday, 325 "%d", pt, ptlim); 326 continue; 327 case 'V': /* ISO 8601 week number */ 328 case 'G': /* ISO 8601 year (four digits) */ 329 case 'g': /* ISO 8601 year (two digits) */ 330 /* 331 ** From Arnold Robbins' strftime version 3.0: "the week number of the 332 ** year (the first Monday as the first day of week 1) as a decimal number 333 ** (01-53)." 334 ** (ado, 1993-05-24) 335 ** 336 ** From "http://www.ft.uni-erlangen.de/~mskuhn/iso-time.html" by Markus Kuhn: 337 ** "Week 01 of a year is per definition the first week which has the 338 ** Thursday in this year, which is equivalent to the week which contains 339 ** the fourth day of January. In other words, the first week of a new year 340 ** is the week which has the majority of its days in the new year. Week 01 341 ** might also contain days from the previous year and the week before week 342 ** 01 of a year is the last week (52 or 53) of the previous year even if 343 ** it contains days from the new year. A week starts with Monday (day 1) 344 ** and ends with Sunday (day 7). For example, the first week of the year 345 ** 1997 lasts from 1996-12-30 to 1997-01-05..." 346 ** (ado, 1996-01-02) 347 */ 348 { 349 int year; 350 int yday; 351 int wday; 352 int w; 353 354 year = t->tm_year + TM_YEAR_BASE; 355 yday = t->tm_yday; 356 wday = t->tm_wday; 357 for ( ; ; ) { 358 int len; 359 int bot; 360 int top; 361 362 len = isleap(year) ? 363 DAYSPERLYEAR : 364 DAYSPERNYEAR; 365 /* 366 ** What yday (-3 ... 3) does 367 ** the ISO year begin on? 368 */ 369 bot = ((yday + 11 - wday) % 370 DAYSPERWEEK) - 3; 371 /* 372 ** What yday does the NEXT 373 ** ISO year begin on? 374 */ 375 top = bot - 376 (len % DAYSPERWEEK); 377 if (top < -3) 378 top += DAYSPERWEEK; 379 top += len; 380 if (yday >= top) { 381 ++year; 382 w = 1; 383 break; 384 } 385 if (yday >= bot) { 386 w = 1 + ((yday - bot) / 387 DAYSPERWEEK); 388 break; 389 } 390 --year; 391 yday += isleap(year) ? 392 DAYSPERLYEAR : 393 DAYSPERNYEAR; 394 } 395 #ifdef XPG4_1994_04_09 396 if ((w == 52 397 && t->tm_mon == TM_JANUARY) 398 || (w == 1 399 && t->tm_mon == TM_DECEMBER)) 400 w = 53; 401 #endif /* defined XPG4_1994_04_09 */ 402 if (*format == 'V') 403 pt = _conv(w, "%02d", 404 pt, ptlim); 405 else if (*format == 'g') { 406 *warnp = IN_ALL; 407 pt = _conv(year % 100, "%02d", 408 pt, ptlim); 409 } else pt = _conv(year, "%04d", 410 pt, ptlim); 411 } 412 continue; 413 case 'v': 414 /* 415 ** From Arnold Robbins' strftime version 3.0: 416 ** "date as dd-bbb-YYYY" 417 ** (ado, 1993-05-24) 418 */ 419 pt = _fmt("%e-%b-%Y", t, pt, ptlim, warnp); 420 continue; 421 case 'W': 422 pt = _conv((t->tm_yday + DAYSPERWEEK - 423 (t->tm_wday ? 424 (t->tm_wday - 1) : 425 (DAYSPERWEEK - 1))) / DAYSPERWEEK, 426 "%02d", pt, ptlim); 427 continue; 428 case 'w': 429 pt = _conv(t->tm_wday, "%d", pt, ptlim); 430 continue; 431 case 'X': 432 pt = _fmt(Locale->t_fmt, t, pt, ptlim, warnp); 433 continue; 434 case 'x': 435 { 436 int warn2 = IN_SOME; 437 438 pt = _fmt(Locale->d_fmt, t, pt, ptlim, &warn2); 439 if (warn2 == IN_ALL) 440 warn2 = IN_THIS; 441 if (warn2 > *warnp) 442 *warnp = warn2; 443 } 444 continue; 445 case 'y': 446 *warnp = IN_ALL; 447 pt = _conv((t->tm_year + TM_YEAR_BASE) % 100, 448 "%02d", pt, ptlim); 449 continue; 450 case 'Y': 451 pt = _conv(t->tm_year + TM_YEAR_BASE, "%04d", 452 pt, ptlim); 453 continue; 454 case 'Z': 455 #ifdef TM_ZONE 456 if (t->TM_ZONE != NULL) 457 pt = _add(t->TM_ZONE, pt, ptlim); 458 else 459 #endif /* defined TM_ZONE */ 460 if (t->tm_isdst >= 0) 461 pt = _add(tzname[t->tm_isdst != 0], 462 pt, ptlim); 463 /* 464 ** C99 says that %Z must be replaced by the 465 ** empty string if the time zone is not 466 ** determinable. 467 */ 468 continue; 469 case 'z': 470 { 471 int diff; 472 char const * sign; 473 474 if (t->tm_isdst < 0) 475 continue; 476 #ifdef TM_GMTOFF 477 diff = (int)t->TM_GMTOFF; 478 #else /* !defined TM_GMTOFF */ 479 /* 480 ** C99 says that the UTC offset must 481 ** be computed by looking only at 482 ** tm_isdst. This requirement is 483 ** incorrect, since it means the code 484 ** must rely on magic (in this case 485 ** altzone and timezone), and the 486 ** magic might not have the correct 487 ** offset. Doing things correctly is 488 ** tricky and requires disobeying C99; 489 ** see GNU C strftime for details. 490 ** For now, punt and conform to the 491 ** standard, even though it's incorrect. 492 ** 493 ** C99 says that %z must be replaced by the 494 ** empty string if the time zone is not 495 ** determinable, so output nothing if the 496 ** appropriate variables are not available. 497 */ 498 #ifndef STD_INSPIRED 499 if (t->tm_isdst == 0) 500 #ifdef USG_COMPAT 501 diff = -timezone; 502 #else /* !defined USG_COMPAT */ 503 continue; 504 #endif /* !defined USG_COMPAT */ 505 else 506 #ifdef ALTZONE 507 diff = -altzone; 508 #else /* !defined ALTZONE */ 509 continue; 510 #endif /* !defined ALTZONE */ 511 #else /* defined STD_INSPIRED */ 512 { 513 struct tm tmp; 514 time_t lct, gct; 515 516 /* 517 ** Get calendar time from t 518 ** being treated as local. 519 */ 520 tmp = *t; /* mktime discards const */ 521 lct = mktime(&tmp); 522 523 if (lct == (time_t)-1) 524 continue; 525 526 /* 527 ** Get calendar time from t 528 ** being treated as GMT. 529 **/ 530 tmp = *t; /* mktime discards const */ 531 gct = timegm(&tmp); 532 533 if (gct == (time_t)-1) 534 continue; 535 536 /* LINTED difference will fit int */ 537 diff = (intmax_t)gct - (intmax_t)lct; 538 } 539 #endif /* defined STD_INSPIRED */ 540 #endif /* !defined TM_GMTOFF */ 541 if (diff < 0) { 542 sign = "-"; 543 diff = -diff; 544 } else sign = "+"; 545 pt = _add(sign, pt, ptlim); 546 diff /= 60; 547 pt = _conv((diff/60)*100 + diff%60, 548 "%04d", pt, ptlim); 549 } 550 continue; 551 #if 0 552 case '+': 553 pt = _fmt(Locale->date_fmt, t, pt, ptlim, 554 warnp); 555 continue; 556 #endif 557 case '%': 558 /* 559 ** X311J/88-090 (4.12.3.5): if conversion char is 560 ** undefined, behavior is undefined. Print out the 561 ** character itself as printf(3) also does. 562 */ 563 default: 564 break; 565 } 566 } 567 if (pt == ptlim) 568 break; 569 *pt++ = *format; 570 } 571 return pt; 572 } 573 574 static char * 575 _conv(n, format, pt, ptlim) 576 const int n; 577 const char * const format; 578 char * const pt; 579 const char * const ptlim; 580 { 581 char buf[INT_STRLEN_MAXIMUM(int) + 1]; 582 583 (void) snprintf(buf, sizeof(buf), format, n); 584 return _add(buf, pt, ptlim); 585 } 586 587 static char * 588 _add(str, pt, ptlim) 589 const char * str; 590 char * pt; 591 const char * const ptlim; 592 { 593 while (pt < ptlim && (*pt = *str++) != '\0') 594 ++pt; 595 return pt; 596 } 597