strftime.c revision 1.18
1 /* $NetBSD: strftime.c,v 1.18 2007/07/31 20:19:16 ginsbach 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 1.18 2007/07/31 20:19:16 ginsbach 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) sprintf(buf, "%ld", 298 (long) mkt); 299 else (void) sprintf(buf, "%lu", 300 (unsigned long) mkt); 301 pt = _add(buf, pt, ptlim); 302 } 303 continue; 304 case 'T': 305 pt = _fmt("%H:%M:%S", t, pt, ptlim, warnp); 306 continue; 307 case 't': 308 pt = _add("\t", pt, ptlim); 309 continue; 310 case 'U': 311 pt = _conv((t->tm_yday + DAYSPERWEEK - 312 t->tm_wday) / DAYSPERWEEK, 313 "%02d", pt, ptlim); 314 continue; 315 case 'u': 316 /* 317 ** From Arnold Robbins' strftime version 3.0: 318 ** "ISO 8601: Weekday as a decimal number 319 ** [1 (Monday) - 7]" 320 ** (ado, 1993-05-24) 321 */ 322 pt = _conv((t->tm_wday == 0) ? 323 DAYSPERWEEK : t->tm_wday, 324 "%d", pt, ptlim); 325 continue; 326 case 'V': /* ISO 8601 week number */ 327 case 'G': /* ISO 8601 year (four digits) */ 328 case 'g': /* ISO 8601 year (two digits) */ 329 /* 330 ** From Arnold Robbins' strftime version 3.0: "the week number of the 331 ** year (the first Monday as the first day of week 1) as a decimal number 332 ** (01-53)." 333 ** (ado, 1993-05-24) 334 ** 335 ** From "http://www.ft.uni-erlangen.de/~mskuhn/iso-time.html" by Markus Kuhn: 336 ** "Week 01 of a year is per definition the first week which has the 337 ** Thursday in this year, which is equivalent to the week which contains 338 ** the fourth day of January. In other words, the first week of a new year 339 ** is the week which has the majority of its days in the new year. Week 01 340 ** might also contain days from the previous year and the week before week 341 ** 01 of a year is the last week (52 or 53) of the previous year even if 342 ** it contains days from the new year. A week starts with Monday (day 1) 343 ** and ends with Sunday (day 7). For example, the first week of the year 344 ** 1997 lasts from 1996-12-30 to 1997-01-05..." 345 ** (ado, 1996-01-02) 346 */ 347 { 348 int year; 349 int yday; 350 int wday; 351 int w; 352 353 year = t->tm_year + TM_YEAR_BASE; 354 yday = t->tm_yday; 355 wday = t->tm_wday; 356 for ( ; ; ) { 357 int len; 358 int bot; 359 int top; 360 361 len = isleap(year) ? 362 DAYSPERLYEAR : 363 DAYSPERNYEAR; 364 /* 365 ** What yday (-3 ... 3) does 366 ** the ISO year begin on? 367 */ 368 bot = ((yday + 11 - wday) % 369 DAYSPERWEEK) - 3; 370 /* 371 ** What yday does the NEXT 372 ** ISO year begin on? 373 */ 374 top = bot - 375 (len % DAYSPERWEEK); 376 if (top < -3) 377 top += DAYSPERWEEK; 378 top += len; 379 if (yday >= top) { 380 ++year; 381 w = 1; 382 break; 383 } 384 if (yday >= bot) { 385 w = 1 + ((yday - bot) / 386 DAYSPERWEEK); 387 break; 388 } 389 --year; 390 yday += isleap(year) ? 391 DAYSPERLYEAR : 392 DAYSPERNYEAR; 393 } 394 #ifdef XPG4_1994_04_09 395 if ((w == 52 396 && t->tm_mon == TM_JANUARY) 397 || (w == 1 398 && t->tm_mon == TM_DECEMBER)) 399 w = 53; 400 #endif /* defined XPG4_1994_04_09 */ 401 if (*format == 'V') 402 pt = _conv(w, "%02d", 403 pt, ptlim); 404 else if (*format == 'g') { 405 *warnp = IN_ALL; 406 pt = _conv(year % 100, "%02d", 407 pt, ptlim); 408 } else pt = _conv(year, "%04d", 409 pt, ptlim); 410 } 411 continue; 412 case 'v': 413 /* 414 ** From Arnold Robbins' strftime version 3.0: 415 ** "date as dd-bbb-YYYY" 416 ** (ado, 1993-05-24) 417 */ 418 pt = _fmt("%e-%b-%Y", t, pt, ptlim, warnp); 419 continue; 420 case 'W': 421 pt = _conv((t->tm_yday + DAYSPERWEEK - 422 (t->tm_wday ? 423 (t->tm_wday - 1) : 424 (DAYSPERWEEK - 1))) / DAYSPERWEEK, 425 "%02d", pt, ptlim); 426 continue; 427 case 'w': 428 pt = _conv(t->tm_wday, "%d", pt, ptlim); 429 continue; 430 case 'X': 431 pt = _fmt(Locale->t_fmt, t, pt, ptlim, warnp); 432 continue; 433 case 'x': 434 { 435 int warn2 = IN_SOME; 436 437 pt = _fmt(Locale->d_fmt, t, pt, ptlim, &warn2); 438 if (warn2 == IN_ALL) 439 warn2 = IN_THIS; 440 if (warn2 > *warnp) 441 *warnp = warn2; 442 } 443 continue; 444 case 'y': 445 *warnp = IN_ALL; 446 pt = _conv((t->tm_year + TM_YEAR_BASE) % 100, 447 "%02d", pt, ptlim); 448 continue; 449 case 'Y': 450 pt = _conv(t->tm_year + TM_YEAR_BASE, "%04d", 451 pt, ptlim); 452 continue; 453 case 'Z': 454 #ifdef TM_ZONE 455 if (t->TM_ZONE != NULL) 456 pt = _add(t->TM_ZONE, pt, ptlim); 457 else 458 #endif /* defined TM_ZONE */ 459 if (t->tm_isdst >= 0) 460 pt = _add(tzname[t->tm_isdst != 0], 461 pt, ptlim); 462 /* 463 ** C99 says that %Z must be replaced by the 464 ** empty string if the time zone is not 465 ** determinable. 466 */ 467 continue; 468 case 'z': 469 { 470 int diff; 471 char const * sign; 472 473 if (t->tm_isdst < 0) 474 continue; 475 #ifdef TM_GMTOFF 476 diff = (int)t->TM_GMTOFF; 477 #else /* !defined TM_GMTOFF */ 478 /* 479 ** C99 says that the UTC offset must 480 ** be computed by looking only at 481 ** tm_isdst. This requirement is 482 ** incorrect, since it means the code 483 ** must rely on magic (in this case 484 ** altzone and timezone), and the 485 ** magic might not have the correct 486 ** offset. Doing things correctly is 487 ** tricky and requires disobeying C99; 488 ** see GNU C strftime for details. 489 ** For now, punt and conform to the 490 ** standard, even though it's incorrect. 491 ** 492 ** C99 says that %z must be replaced by the 493 ** empty string if the time zone is not 494 ** determinable, so output nothing if the 495 ** appropriate variables are not available. 496 */ 497 #ifndef STD_INSPIRED 498 if (t->tm_isdst == 0) 499 #ifdef USG_COMPAT 500 diff = -timezone; 501 #else /* !defined USG_COMPAT */ 502 continue; 503 #endif /* !defined USG_COMPAT */ 504 else 505 #ifdef ALTZONE 506 diff = -altzone; 507 #else /* !defined ALTZONE */ 508 continue; 509 #endif /* !defined ALTZONE */ 510 #else /* defined STD_INSPIRED */ 511 { 512 struct tm tmp; 513 time_t lct, gct; 514 515 /* 516 ** Get calendar time from t 517 ** being treated as local. 518 */ 519 tmp = *t; /* mktime discards const */ 520 lct = mktime(&tmp); 521 522 if (lct == (time_t)-1) 523 continue; 524 525 /* 526 ** Get calendar time from t 527 ** being treated as GMT. 528 **/ 529 tmp = *t; /* mktime discards const */ 530 gct = timegm(&tmp); 531 532 if (gct == (time_t)-1) 533 continue; 534 535 /* LINTED difference will fit int */ 536 diff = (intmax_t)gct - (intmax_t)lct; 537 } 538 #endif /* defined STD_INSPIRED */ 539 #endif /* !defined TM_GMTOFF */ 540 if (diff < 0) { 541 sign = "-"; 542 diff = -diff; 543 } else sign = "+"; 544 pt = _add(sign, pt, ptlim); 545 diff /= 60; 546 pt = _conv((diff/60)*100 + diff%60, 547 "%04d", pt, ptlim); 548 } 549 continue; 550 #if 0 551 case '+': 552 pt = _fmt(Locale->date_fmt, t, pt, ptlim, 553 warnp); 554 continue; 555 #endif 556 case '%': 557 /* 558 ** X311J/88-090 (4.12.3.5): if conversion char is 559 ** undefined, behavior is undefined. Print out the 560 ** character itself as printf(3) also does. 561 */ 562 default: 563 break; 564 } 565 } 566 if (pt == ptlim) 567 break; 568 *pt++ = *format; 569 } 570 return pt; 571 } 572 573 static char * 574 _conv(n, format, pt, ptlim) 575 const int n; 576 const char * const format; 577 char * const pt; 578 const char * const ptlim; 579 { 580 char buf[INT_STRLEN_MAXIMUM(int) + 1]; 581 582 (void) sprintf(buf, format, n); 583 return _add(buf, pt, ptlim); 584 } 585 586 static char * 587 _add(str, pt, ptlim) 588 const char * str; 589 char * pt; 590 const char * const ptlim; 591 { 592 while (pt < ptlim && (*pt = *str++) != '\0') 593 ++pt; 594 return pt; 595 } 596
Indexes created Thu Sep 25 08:09:54 GMT 2025