strftime.c revision 1.15
1 /* $NetBSD: strftime.c,v 1.15 2004/05/11 09:32:02 kleink 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 1.15 2004/05/11 09:32:02 kleink 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 #ifdef _LIBC 22 #undef TM_ZONE 23 #endif 24 25 /* 26 ** Copyright (c) 1989, 1993 27 ** The Regents of the University of California. All rights reserved. 28 ** 29 ** Redistribution and use in source and binary forms, with or without 30 ** modification, are permitted provided that the following conditions 31 ** are met: 32 ** 1. Redistributions of source code must retain the above copyright 33 ** notice, this list of conditions and the following disclaimer. 34 ** 2. Redistributions in binary form must reproduce the above copyright 35 ** notice, this list of conditions and the following disclaimer in the 36 ** documentation and/or other materials provided with the distribution. 37 ** 3. All advertising materials mentioning features or use of this software 38 ** must display the following acknowledgement: 39 ** This product includes software developed by the University of 40 ** California, Berkeley and its contributors. 41 ** 4. Neither the name of the University nor the names of its contributors 42 ** may be used to endorse or promote products derived from this software 43 ** without specific prior written permission. 44 ** 45 ** THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 46 ** ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 47 ** IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 48 ** ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 49 ** FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 50 ** DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 51 ** OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 52 ** HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 53 ** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 54 ** OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 55 ** SUCH DAMAGE. 56 */ 57 58 #ifndef LIBC_SCCS 59 #ifndef lint 60 static const char sccsid[] = "@(#)strftime.c 5.4 (Berkeley) 3/14/89"; 61 #endif /* !defined lint */ 62 #endif /* !defined LIBC_SCCS */ 63 64 #include "tzfile.h" 65 #include "fcntl.h" 66 #include "locale.h" 67 68 #include "sys/localedef.h" 69 #define Locale _CurrentTimeLocale 70 71 static char * _add P((const char *, char *, const char *)); 72 static char * _conv P((int, const char *, char *, const char *)); 73 static char * _fmt P((const char *, const struct tm *, char *, const char *, int *)); 74 75 #define NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU 76 77 #ifndef YEAR_2000_NAME 78 #define YEAR_2000_NAME "CHECK_STRFTIME_FORMATS_FOR_TWO_DIGIT_YEARS" 79 #endif /* !defined YEAR_2000_NAME */ 80 81 82 #define IN_NONE 0 83 #define IN_SOME 1 84 #define IN_THIS 2 85 #define IN_ALL 3 86 87 size_t 88 strftime(s, maxsize, format, t) 89 char * const s; 90 const size_t maxsize; 91 const char * const format; 92 const struct tm * const t; 93 { 94 char * p; 95 int warn; 96 97 tzset(); 98 warn = IN_NONE; 99 p = _fmt(((format == NULL) ? "%c" : format), t, s, s + maxsize, &warn); 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(stderr, "\n"); 103 if (format == NULL) 104 (void) fprintf(stderr, "NULL strftime format "); 105 else (void) fprintf(stderr, "strftime format \"%s\" ", 106 format); 107 (void) fprintf(stderr, "yields only two digits of years in "); 108 if (warn == IN_SOME) 109 (void) fprintf(stderr, "some locales"); 110 else if (warn == IN_THIS) 111 (void) fprintf(stderr, "the current locale"); 112 else (void) fprintf(stderr, "all locales"); 113 (void) fprintf(stderr, "\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 static char * 123 _fmt(format, t, pt, ptlim, warnp) 124 const char * format; 125 const struct tm * const t; 126 char * pt; 127 const char * const ptlim; 128 int * warnp; 129 { 130 for ( ; *format; ++format) { 131 if (*format == '%') { 132 label: 133 switch (*++format) { 134 case '\0': 135 --format; 136 break; 137 case 'A': 138 pt = _add((t->tm_wday < 0 || 139 t->tm_wday >= DAYSPERWEEK) ? 140 "?" : Locale->day[t->tm_wday], 141 pt, ptlim); 142 continue; 143 case 'a': 144 pt = _add((t->tm_wday < 0 || 145 t->tm_wday >= DAYSPERWEEK) ? 146 "?" : Locale->abday[t->tm_wday], 147 pt, ptlim); 148 continue; 149 case 'B': 150 pt = _add((t->tm_mon < 0 || 151 t->tm_mon >= MONSPERYEAR) ? 152 "?" : Locale->mon[t->tm_mon], 153 pt, ptlim); 154 continue; 155 case 'b': 156 case 'h': 157 pt = _add((t->tm_mon < 0 || 158 t->tm_mon >= MONSPERYEAR) ? 159 "?" : Locale->abmon[t->tm_mon], 160 pt, ptlim); 161 continue; 162 case 'C': 163 /* 164 ** %C used to do a... 165 ** _fmt("%a %b %e %X %Y", t); 166 ** ...whereas now POSIX 1003.2 calls for 167 ** something completely different. 168 ** (ado, 1993-05-24) 169 */ 170 pt = _conv((t->tm_year + TM_YEAR_BASE) / 100, 171 "%02d", pt, ptlim); 172 continue; 173 case 'c': 174 { 175 int warn2 = IN_SOME; 176 177 pt = _fmt(Locale->d_t_fmt, t, pt, ptlim, warnp); 178 if (warn2 == IN_ALL) 179 warn2 = IN_THIS; 180 if (warn2 > *warnp) 181 *warnp = warn2; 182 } 183 continue; 184 case 'D': 185 pt = _fmt("%m/%d/%y", t, pt, ptlim, warnp); 186 continue; 187 case 'd': 188 pt = _conv(t->tm_mday, "%02d", pt, ptlim); 189 continue; 190 case 'E': 191 case 'O': 192 /* 193 ** C99 locale modifiers. 194 ** The sequences 195 ** %Ec %EC %Ex %EX %Ey %EY 196 ** %Od %oe %OH %OI %Om %OM 197 ** %OS %Ou %OU %OV %Ow %OW %Oy 198 ** are supposed to provide alternate 199 ** representations. 200 */ 201 goto label; 202 case 'e': 203 pt = _conv(t->tm_mday, "%2d", pt, ptlim); 204 continue; 205 case 'F': 206 pt = _fmt("%Y-%m-%d", t, pt, ptlim, warnp); 207 continue; 208 case 'H': 209 pt = _conv(t->tm_hour, "%02d", pt, ptlim); 210 continue; 211 case 'I': 212 pt = _conv((t->tm_hour % 12) ? 213 (t->tm_hour % 12) : 12, 214 "%02d", pt, ptlim); 215 continue; 216 case 'j': 217 pt = _conv(t->tm_yday + 1, "%03d", pt, ptlim); 218 continue; 219 case 'k': 220 /* 221 ** This used to be... 222 ** _conv(t->tm_hour % 12 ? 223 ** t->tm_hour % 12 : 12, 2, ' '); 224 ** ...and has been changed to the below to 225 ** match SunOS 4.1.1 and Arnold Robbins' 226 ** strftime version 3.0. That is, "%k" and 227 ** "%l" have been swapped. 228 ** (ado, 1993-05-24) 229 */ 230 pt = _conv(t->tm_hour, "%2d", pt, ptlim); 231 continue; 232 #ifdef KITCHEN_SINK 233 case 'K': 234 /* 235 ** After all this time, still unclaimed! 236 */ 237 pt = _add("kitchen sink", pt, ptlim); 238 continue; 239 #endif /* defined KITCHEN_SINK */ 240 case 'l': 241 /* 242 ** This used to be... 243 ** _conv(t->tm_hour, 2, ' '); 244 ** ...and has been changed to the below to 245 ** match SunOS 4.1.1 and Arnold Robbin's 246 ** strftime version 3.0. That is, "%k" and 247 ** "%l" have been swapped. 248 ** (ado, 1993-05-24) 249 */ 250 pt = _conv((t->tm_hour % 12) ? 251 (t->tm_hour % 12) : 12, 252 "%2d", pt, ptlim); 253 continue; 254 case 'M': 255 pt = _conv(t->tm_min, "%02d", pt, ptlim); 256 continue; 257 case 'm': 258 pt = _conv(t->tm_mon + 1, "%02d", pt, ptlim); 259 continue; 260 case 'n': 261 pt = _add("\n", pt, ptlim); 262 continue; 263 case 'p': 264 pt = _add((t->tm_hour >= (HOURSPERDAY / 2)) ? 265 Locale->am_pm[1] : 266 Locale->am_pm[0], 267 pt, ptlim); 268 continue; 269 case 'R': 270 pt = _fmt("%H:%M", t, pt, ptlim, warnp); 271 continue; 272 case 'r': 273 pt = _fmt("%I:%M:%S %p", t, pt, ptlim, warnp); 274 continue; 275 case 'S': 276 pt = _conv(t->tm_sec, "%02d", pt, ptlim); 277 continue; 278 case 's': 279 { 280 struct tm tm; 281 char buf[INT_STRLEN_MAXIMUM( 282 time_t) + 1]; 283 time_t mkt; 284 285 tm = *t; 286 mkt = mktime(&tm); 287 /* CONSTCOND */ 288 if (TYPE_SIGNED(time_t)) 289 (void) sprintf(buf, "%ld", 290 (long) mkt); 291 else (void) sprintf(buf, "%lu", 292 (unsigned long) mkt); 293 pt = _add(buf, pt, ptlim); 294 } 295 continue; 296 case 'T': 297 pt = _fmt("%H:%M:%S", t, pt, ptlim, warnp); 298 continue; 299 case 't': 300 pt = _add("\t", pt, ptlim); 301 continue; 302 case 'U': 303 pt = _conv((t->tm_yday + DAYSPERWEEK - 304 t->tm_wday) / DAYSPERWEEK, 305 "%02d", pt, ptlim); 306 continue; 307 case 'u': 308 /* 309 ** From Arnold Robbins' strftime version 3.0: 310 ** "ISO 8601: Weekday as a decimal number 311 ** [1 (Monday) - 7]" 312 ** (ado, 1993-05-24) 313 */ 314 pt = _conv((t->tm_wday == 0) ? 315 DAYSPERWEEK : t->tm_wday, 316 "%d", pt, ptlim); 317 continue; 318 case 'V': /* ISO 8601 week number */ 319 case 'G': /* ISO 8601 year (four digits) */ 320 case 'g': /* ISO 8601 year (two digits) */ 321 /* 322 ** From Arnold Robbins' strftime version 3.0: "the week number of the 323 ** year (the first Monday as the first day of week 1) as a decimal number 324 ** (01-53)." 325 ** (ado, 1993-05-24) 326 ** 327 ** From "http://www.ft.uni-erlangen.de/~mskuhn/iso-time.html" by Markus Kuhn: 328 ** "Week 01 of a year is per definition the first week which has the 329 ** Thursday in this year, which is equivalent to the week which contains 330 ** the fourth day of January. In other words, the first week of a new year 331 ** is the week which has the majority of its days in the new year. Week 01 332 ** might also contain days from the previous year and the week before week 333 ** 01 of a year is the last week (52 or 53) of the previous year even if 334 ** it contains days from the new year. A week starts with Monday (day 1) 335 ** and ends with Sunday (day 7). For example, the first week of the year 336 ** 1997 lasts from 1996-12-30 to 1997-01-05..." 337 ** (ado, 1996-01-02) 338 */ 339 { 340 int year; 341 int yday; 342 int wday; 343 int w; 344 345 year = t->tm_year + TM_YEAR_BASE; 346 yday = t->tm_yday; 347 wday = t->tm_wday; 348 for ( ; ; ) { 349 int len; 350 int bot; 351 int top; 352 353 len = isleap(year) ? 354 DAYSPERLYEAR : 355 DAYSPERNYEAR; 356 /* 357 ** What yday (-3 ... 3) does 358 ** the ISO year begin on? 359 */ 360 bot = ((yday + 11 - wday) % 361 DAYSPERWEEK) - 3; 362 /* 363 ** What yday does the NEXT 364 ** ISO year begin on? 365 */ 366 top = bot - 367 (len % DAYSPERWEEK); 368 if (top < -3) 369 top += DAYSPERWEEK; 370 top += len; 371 if (yday >= top) { 372 ++year; 373 w = 1; 374 break; 375 } 376 if (yday >= bot) { 377 w = 1 + ((yday - bot) / 378 DAYSPERWEEK); 379 break; 380 } 381 --year; 382 yday += isleap(year) ? 383 DAYSPERLYEAR : 384 DAYSPERNYEAR; 385 } 386 #ifdef XPG4_1994_04_09 387 if ((w == 52 388 && t->tm_mon == TM_JANUARY) 389 || (w == 1 390 && t->tm_mon == TM_DECEMBER)) 391 w = 53; 392 #endif /* defined XPG4_1994_04_09 */ 393 if (*format == 'V') 394 pt = _conv(w, "%02d", 395 pt, ptlim); 396 else if (*format == 'g') { 397 *warnp = IN_ALL; 398 pt = _conv(year % 100, "%02d", 399 pt, ptlim); 400 } else pt = _conv(year, "%04d", 401 pt, ptlim); 402 } 403 continue; 404 case 'v': 405 /* 406 ** From Arnold Robbins' strftime version 3.0: 407 ** "date as dd-bbb-YYYY" 408 ** (ado, 1993-05-24) 409 */ 410 pt = _fmt("%e-%b-%Y", t, pt, ptlim, warnp); 411 continue; 412 case 'W': 413 pt = _conv((t->tm_yday + DAYSPERWEEK - 414 (t->tm_wday ? 415 (t->tm_wday - 1) : 416 (DAYSPERWEEK - 1))) / DAYSPERWEEK, 417 "%02d", pt, ptlim); 418 continue; 419 case 'w': 420 pt = _conv(t->tm_wday, "%d", pt, ptlim); 421 continue; 422 case 'X': 423 pt = _fmt(Locale->t_fmt, t, pt, ptlim, warnp); 424 continue; 425 case 'x': 426 { 427 int warn2 = IN_SOME; 428 429 pt = _fmt(Locale->d_fmt, t, pt, ptlim, &warn2); 430 if (warn2 == IN_ALL) 431 warn2 = IN_THIS; 432 if (warn2 > *warnp) 433 *warnp = warn2; 434 } 435 continue; 436 case 'y': 437 *warnp = IN_ALL; 438 pt = _conv((t->tm_year + TM_YEAR_BASE) % 100, 439 "%02d", pt, ptlim); 440 continue; 441 case 'Y': 442 pt = _conv(t->tm_year + TM_YEAR_BASE, "%04d", 443 pt, ptlim); 444 continue; 445 case 'Z': 446 #ifdef TM_ZONE 447 if (t->TM_ZONE != NULL) 448 pt = _add(t->TM_ZONE, pt, ptlim); 449 else 450 #endif /* defined TM_ZONE */ 451 if (t->tm_isdst >= 0) 452 pt = _add(tzname[t->tm_isdst != 0], 453 pt, ptlim); 454 /* 455 ** C99 says that %Z must be replaced by the 456 ** empty string if the time zone is not 457 ** determinable. 458 */ 459 continue; 460 case 'z': 461 { 462 int diff; 463 char const * sign; 464 465 if (t->tm_isdst < 0) 466 continue; 467 #ifdef TM_GMTOFF 468 diff = (int)t->TM_GMTOFF; 469 #else /* !defined TM_GMTOFF */ 470 /* 471 ** C99 says that the UTC offset must 472 ** be computed by looking only at 473 ** tm_isdst. This requirement is 474 ** incorrect, since it means the code 475 ** must rely on magic (in this case 476 ** altzone and timezone), and the 477 ** magic might not have the correct 478 ** offset. Doing things correctly is 479 ** tricky and requires disobeying C99; 480 ** see GNU C strftime for details. 481 ** For now, punt and conform to the 482 ** standard, even though it's incorrect. 483 ** 484 ** C99 says that %z must be replaced by the 485 ** empty string if the time zone is not 486 ** determinable, so output nothing if the 487 ** appropriate variables are not available. 488 */ 489 if (t->tm_isdst == 0) 490 #ifdef USG_COMPAT 491 diff = -timezone; 492 #else /* !defined USG_COMPAT */ 493 continue; 494 #endif /* !defined USG_COMPAT */ 495 else 496 #ifdef ALTZONE 497 diff = -altzone; 498 #else /* !defined ALTZONE */ 499 continue; 500 #endif /* !defined ALTZONE */ 501 #endif /* !defined TM_GMTOFF */ 502 if (diff < 0) { 503 sign = "-"; 504 diff = -diff; 505 } else sign = "+"; 506 pt = _add(sign, pt, ptlim); 507 diff /= 60; 508 pt = _conv((diff/60)*100 + diff%60, 509 "%04d", pt, ptlim); 510 } 511 continue; 512 #if 0 513 case '+': 514 pt = _fmt(Locale->date_fmt, t, pt, ptlim, 515 warnp); 516 continue; 517 #endif 518 case '%': 519 /* 520 ** X311J/88-090 (4.12.3.5): if conversion char is 521 ** undefined, behavior is undefined. Print out the 522 ** character itself as printf(3) also does. 523 */ 524 default: 525 break; 526 } 527 } 528 if (pt == ptlim) 529 break; 530 *pt++ = *format; 531 } 532 return pt; 533 } 534 535 static char * 536 _conv(n, format, pt, ptlim) 537 const int n; 538 const char * const format; 539 char * const pt; 540 const char * const ptlim; 541 { 542 char buf[INT_STRLEN_MAXIMUM(int) + 1]; 543 544 (void) sprintf(buf, format, n); 545 return _add(buf, pt, ptlim); 546 } 547 548 static char * 549 _add(str, pt, ptlim) 550 const char * str; 551 char * pt; 552 const char * const ptlim; 553 { 554 while (pt < ptlim && (*pt = *str++) != '\0') 555 ++pt; 556 return pt; 557 } 558
Indexes created Thu Sep 25 16:09:42 GMT 2025