strftime.c revision 1.14
1 /* $NetBSD: strftime.c,v 1.14 2002/10/02 06:56:24 itojun 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 1.14 2002/10/02 06:56:24 itojun 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 ** Copyright (c) 1989, 1993 23 ** The Regents of the University of California. All rights reserved. 24 ** 25 ** Redistribution and use in source and binary forms, with or without 26 ** modification, are permitted provided that the following conditions 27 ** are met: 28 ** 1. Redistributions of source code must retain the above copyright 29 ** notice, this list of conditions and the following disclaimer. 30 ** 2. Redistributions in binary form must reproduce the above copyright 31 ** notice, this list of conditions and the following disclaimer in the 32 ** documentation and/or other materials provided with the distribution. 33 ** 3. All advertising materials mentioning features or use of this software 34 ** must display the following acknowledgement: 35 ** This product includes software developed by the University of 36 ** California, Berkeley and its contributors. 37 ** 4. Neither the name of the University nor the names of its contributors 38 ** may be used to endorse or promote products derived from this software 39 ** without specific prior written permission. 40 ** 41 ** THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 42 ** ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 43 ** IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 44 ** ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 45 ** FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 46 ** DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 47 ** OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 48 ** HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 49 ** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 50 ** OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 51 ** SUCH DAMAGE. 52 */ 53 54 #ifndef LIBC_SCCS 55 #ifndef lint 56 static const char sccsid[] = "@(#)strftime.c 5.4 (Berkeley) 3/14/89"; 57 #endif /* !defined lint */ 58 #endif /* !defined LIBC_SCCS */ 59 60 #include "tzfile.h" 61 #include "fcntl.h" 62 #include "locale.h" 63 64 #include "sys/localedef.h" 65 #define Locale _CurrentTimeLocale 66 67 static char * _add P((const char *, char *, const char *)); 68 static char * _conv P((int, const char *, char *, const char *)); 69 static char * _fmt P((const char *, const struct tm *, char *, const char *, int *)); 70 71 #define NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU 72 73 #ifndef YEAR_2000_NAME 74 #define YEAR_2000_NAME "CHECK_STRFTIME_FORMATS_FOR_TWO_DIGIT_YEARS" 75 #endif /* !defined YEAR_2000_NAME */ 76 77 78 #define IN_NONE 0 79 #define IN_SOME 1 80 #define IN_THIS 2 81 #define IN_ALL 3 82 83 size_t 84 strftime(s, maxsize, format, t) 85 char * const s; 86 const size_t maxsize; 87 const char * const format; 88 const struct tm * const t; 89 { 90 char * p; 91 int warn; 92 93 tzset(); 94 warn = IN_NONE; 95 p = _fmt(((format == NULL) ? "%c" : format), t, s, s + maxsize, &warn); 96 #ifndef NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU 97 if (warn != IN_NONE && getenv(YEAR_2000_NAME) != NULL) { 98 (void) fprintf(stderr, "\n"); 99 if (format == NULL) 100 (void) fprintf(stderr, "NULL strftime format "); 101 else (void) fprintf(stderr, "strftime format \"%s\" ", 102 format); 103 (void) fprintf(stderr, "yields only two digits of years in "); 104 if (warn == IN_SOME) 105 (void) fprintf(stderr, "some locales"); 106 else if (warn == IN_THIS) 107 (void) fprintf(stderr, "the current locale"); 108 else (void) fprintf(stderr, "all locales"); 109 (void) fprintf(stderr, "\n"); 110 } 111 #endif /* !defined NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU */ 112 if (p == s + maxsize) 113 return 0; 114 *p = '\0'; 115 return p - s; 116 } 117 118 static char * 119 _fmt(format, t, pt, ptlim, warnp) 120 const char * format; 121 const struct tm * const t; 122 char * pt; 123 const char * const ptlim; 124 int * warnp; 125 { 126 for ( ; *format; ++format) { 127 if (*format == '%') { 128 label: 129 switch (*++format) { 130 case '\0': 131 --format; 132 break; 133 case 'A': 134 pt = _add((t->tm_wday < 0 || 135 t->tm_wday >= DAYSPERWEEK) ? 136 "?" : Locale->day[t->tm_wday], 137 pt, ptlim); 138 continue; 139 case 'a': 140 pt = _add((t->tm_wday < 0 || 141 t->tm_wday >= DAYSPERWEEK) ? 142 "?" : Locale->abday[t->tm_wday], 143 pt, ptlim); 144 continue; 145 case 'B': 146 pt = _add((t->tm_mon < 0 || 147 t->tm_mon >= MONSPERYEAR) ? 148 "?" : Locale->mon[t->tm_mon], 149 pt, ptlim); 150 continue; 151 case 'b': 152 case 'h': 153 pt = _add((t->tm_mon < 0 || 154 t->tm_mon >= MONSPERYEAR) ? 155 "?" : Locale->abmon[t->tm_mon], 156 pt, ptlim); 157 continue; 158 case 'C': 159 /* 160 ** %C used to do a... 161 ** _fmt("%a %b %e %X %Y", t); 162 ** ...whereas now POSIX 1003.2 calls for 163 ** something completely different. 164 ** (ado, 1993-05-24) 165 */ 166 pt = _conv((t->tm_year + TM_YEAR_BASE) / 100, 167 "%02d", pt, ptlim); 168 continue; 169 case 'c': 170 { 171 int warn2 = IN_SOME; 172 173 pt = _fmt(Locale->d_t_fmt, t, pt, ptlim, warnp); 174 if (warn2 == IN_ALL) 175 warn2 = IN_THIS; 176 if (warn2 > *warnp) 177 *warnp = warn2; 178 } 179 continue; 180 case 'D': 181 pt = _fmt("%m/%d/%y", t, pt, ptlim, warnp); 182 continue; 183 case 'd': 184 pt = _conv(t->tm_mday, "%02d", pt, ptlim); 185 continue; 186 case 'E': 187 case 'O': 188 /* 189 ** C99 locale modifiers. 190 ** The sequences 191 ** %Ec %EC %Ex %EX %Ey %EY 192 ** %Od %oe %OH %OI %Om %OM 193 ** %OS %Ou %OU %OV %Ow %OW %Oy 194 ** are supposed to provide alternate 195 ** representations. 196 */ 197 goto label; 198 case 'e': 199 pt = _conv(t->tm_mday, "%2d", pt, ptlim); 200 continue; 201 case 'F': 202 pt = _fmt("%Y-%m-%d", t, pt, ptlim, warnp); 203 continue; 204 case 'H': 205 pt = _conv(t->tm_hour, "%02d", pt, ptlim); 206 continue; 207 case 'I': 208 pt = _conv((t->tm_hour % 12) ? 209 (t->tm_hour % 12) : 12, 210 "%02d", pt, ptlim); 211 continue; 212 case 'j': 213 pt = _conv(t->tm_yday + 1, "%03d", pt, ptlim); 214 continue; 215 case 'k': 216 /* 217 ** This used to be... 218 ** _conv(t->tm_hour % 12 ? 219 ** t->tm_hour % 12 : 12, 2, ' '); 220 ** ...and has been changed to the below to 221 ** match SunOS 4.1.1 and Arnold Robbins' 222 ** strftime version 3.0. That is, "%k" and 223 ** "%l" have been swapped. 224 ** (ado, 1993-05-24) 225 */ 226 pt = _conv(t->tm_hour, "%2d", pt, ptlim); 227 continue; 228 #ifdef KITCHEN_SINK 229 case 'K': 230 /* 231 ** After all this time, still unclaimed! 232 */ 233 pt = _add("kitchen sink", pt, ptlim); 234 continue; 235 #endif /* defined KITCHEN_SINK */ 236 case 'l': 237 /* 238 ** This used to be... 239 ** _conv(t->tm_hour, 2, ' '); 240 ** ...and has been changed to the below to 241 ** match SunOS 4.1.1 and Arnold Robbin's 242 ** strftime version 3.0. That is, "%k" and 243 ** "%l" have been swapped. 244 ** (ado, 1993-05-24) 245 */ 246 pt = _conv((t->tm_hour % 12) ? 247 (t->tm_hour % 12) : 12, 248 "%2d", pt, ptlim); 249 continue; 250 case 'M': 251 pt = _conv(t->tm_min, "%02d", pt, ptlim); 252 continue; 253 case 'm': 254 pt = _conv(t->tm_mon + 1, "%02d", pt, ptlim); 255 continue; 256 case 'n': 257 pt = _add("\n", pt, ptlim); 258 continue; 259 case 'p': 260 pt = _add((t->tm_hour >= (HOURSPERDAY / 2)) ? 261 Locale->am_pm[1] : 262 Locale->am_pm[0], 263 pt, ptlim); 264 continue; 265 case 'R': 266 pt = _fmt("%H:%M", t, pt, ptlim, warnp); 267 continue; 268 case 'r': 269 pt = _fmt("%I:%M:%S %p", t, pt, ptlim, warnp); 270 continue; 271 case 'S': 272 pt = _conv(t->tm_sec, "%02d", pt, ptlim); 273 continue; 274 case 's': 275 { 276 struct tm tm; 277 char buf[INT_STRLEN_MAXIMUM( 278 time_t) + 1]; 279 time_t mkt; 280 281 tm = *t; 282 mkt = mktime(&tm); 283 /* CONSTCOND */ 284 if (TYPE_SIGNED(time_t)) 285 (void) sprintf(buf, "%ld", 286 (long) mkt); 287 else (void) sprintf(buf, "%lu", 288 (unsigned long) mkt); 289 pt = _add(buf, pt, ptlim); 290 } 291 continue; 292 case 'T': 293 pt = _fmt("%H:%M:%S", t, pt, ptlim, warnp); 294 continue; 295 case 't': 296 pt = _add("\t", pt, ptlim); 297 continue; 298 case 'U': 299 pt = _conv((t->tm_yday + DAYSPERWEEK - 300 t->tm_wday) / DAYSPERWEEK, 301 "%02d", pt, ptlim); 302 continue; 303 case 'u': 304 /* 305 ** From Arnold Robbins' strftime version 3.0: 306 ** "ISO 8601: Weekday as a decimal number 307 ** [1 (Monday) - 7]" 308 ** (ado, 1993-05-24) 309 */ 310 pt = _conv((t->tm_wday == 0) ? 311 DAYSPERWEEK : t->tm_wday, 312 "%d", pt, ptlim); 313 continue; 314 case 'V': /* ISO 8601 week number */ 315 case 'G': /* ISO 8601 year (four digits) */ 316 case 'g': /* ISO 8601 year (two digits) */ 317 /* 318 ** From Arnold Robbins' strftime version 3.0: "the week number of the 319 ** year (the first Monday as the first day of week 1) as a decimal number 320 ** (01-53)." 321 ** (ado, 1993-05-24) 322 ** 323 ** From "http://www.ft.uni-erlangen.de/~mskuhn/iso-time.html" by Markus Kuhn: 324 ** "Week 01 of a year is per definition the first week which has the 325 ** Thursday in this year, which is equivalent to the week which contains 326 ** the fourth day of January. In other words, the first week of a new year 327 ** is the week which has the majority of its days in the new year. Week 01 328 ** might also contain days from the previous year and the week before week 329 ** 01 of a year is the last week (52 or 53) of the previous year even if 330 ** it contains days from the new year. A week starts with Monday (day 1) 331 ** and ends with Sunday (day 7). For example, the first week of the year 332 ** 1997 lasts from 1996-12-30 to 1997-01-05..." 333 ** (ado, 1996-01-02) 334 */ 335 { 336 int year; 337 int yday; 338 int wday; 339 int w; 340 341 year = t->tm_year + TM_YEAR_BASE; 342 yday = t->tm_yday; 343 wday = t->tm_wday; 344 for ( ; ; ) { 345 int len; 346 int bot; 347 int top; 348 349 len = isleap(year) ? 350 DAYSPERLYEAR : 351 DAYSPERNYEAR; 352 /* 353 ** What yday (-3 ... 3) does 354 ** the ISO year begin on? 355 */ 356 bot = ((yday + 11 - wday) % 357 DAYSPERWEEK) - 3; 358 /* 359 ** What yday does the NEXT 360 ** ISO year begin on? 361 */ 362 top = bot - 363 (len % DAYSPERWEEK); 364 if (top < -3) 365 top += DAYSPERWEEK; 366 top += len; 367 if (yday >= top) { 368 ++year; 369 w = 1; 370 break; 371 } 372 if (yday >= bot) { 373 w = 1 + ((yday - bot) / 374 DAYSPERWEEK); 375 break; 376 } 377 --year; 378 yday += isleap(year) ? 379 DAYSPERLYEAR : 380 DAYSPERNYEAR; 381 } 382 #ifdef XPG4_1994_04_09 383 if ((w == 52 384 && t->tm_mon == TM_JANUARY) 385 || (w == 1 386 && t->tm_mon == TM_DECEMBER)) 387 w = 53; 388 #endif /* defined XPG4_1994_04_09 */ 389 if (*format == 'V') 390 pt = _conv(w, "%02d", 391 pt, ptlim); 392 else if (*format == 'g') { 393 *warnp = IN_ALL; 394 pt = _conv(year % 100, "%02d", 395 pt, ptlim); 396 } else pt = _conv(year, "%04d", 397 pt, ptlim); 398 } 399 continue; 400 case 'v': 401 /* 402 ** From Arnold Robbins' strftime version 3.0: 403 ** "date as dd-bbb-YYYY" 404 ** (ado, 1993-05-24) 405 */ 406 pt = _fmt("%e-%b-%Y", t, pt, ptlim, warnp); 407 continue; 408 case 'W': 409 pt = _conv((t->tm_yday + DAYSPERWEEK - 410 (t->tm_wday ? 411 (t->tm_wday - 1) : 412 (DAYSPERWEEK - 1))) / DAYSPERWEEK, 413 "%02d", pt, ptlim); 414 continue; 415 case 'w': 416 pt = _conv(t->tm_wday, "%d", pt, ptlim); 417 continue; 418 case 'X': 419 pt = _fmt(Locale->t_fmt, t, pt, ptlim, warnp); 420 continue; 421 case 'x': 422 { 423 int warn2 = IN_SOME; 424 425 pt = _fmt(Locale->d_fmt, t, pt, ptlim, &warn2); 426 if (warn2 == IN_ALL) 427 warn2 = IN_THIS; 428 if (warn2 > *warnp) 429 *warnp = warn2; 430 } 431 continue; 432 case 'y': 433 *warnp = IN_ALL; 434 pt = _conv((t->tm_year + TM_YEAR_BASE) % 100, 435 "%02d", pt, ptlim); 436 continue; 437 case 'Y': 438 pt = _conv(t->tm_year + TM_YEAR_BASE, "%04d", 439 pt, ptlim); 440 continue; 441 case 'Z': 442 #ifdef TM_ZONE 443 if (t->TM_ZONE != NULL) 444 pt = _add(t->TM_ZONE, pt, ptlim); 445 else 446 #endif /* defined TM_ZONE */ 447 if (t->tm_isdst >= 0) 448 pt = _add(tzname[t->tm_isdst != 0], 449 pt, ptlim); 450 /* 451 ** C99 says that %Z must be replaced by the 452 ** empty string if the time zone is not 453 ** determinable. 454 */ 455 continue; 456 case 'z': 457 { 458 int diff; 459 char const * sign; 460 461 if (t->tm_isdst < 0) 462 continue; 463 #ifdef TM_GMTOFF 464 diff = (int)t->TM_GMTOFF; 465 #else /* !defined TM_GMTOFF */ 466 /* 467 ** C99 says that the UTC offset must 468 ** be computed by looking only at 469 ** tm_isdst. This requirement is 470 ** incorrect, since it means the code 471 ** must rely on magic (in this case 472 ** altzone and timezone), and the 473 ** magic might not have the correct 474 ** offset. Doing things correctly is 475 ** tricky and requires disobeying C99; 476 ** see GNU C strftime for details. 477 ** For now, punt and conform to the 478 ** standard, even though it's incorrect. 479 ** 480 ** C99 says that %z must be replaced by the 481 ** empty string if the time zone is not 482 ** determinable, so output nothing if the 483 ** appropriate variables are not available. 484 */ 485 if (t->tm_isdst == 0) 486 #ifdef USG_COMPAT 487 diff = -timezone; 488 #else /* !defined USG_COMPAT */ 489 continue; 490 #endif /* !defined USG_COMPAT */ 491 else 492 #ifdef ALTZONE 493 diff = -altzone; 494 #else /* !defined ALTZONE */ 495 continue; 496 #endif /* !defined ALTZONE */ 497 #endif /* !defined TM_GMTOFF */ 498 if (diff < 0) { 499 sign = "-"; 500 diff = -diff; 501 } else sign = "+"; 502 pt = _add(sign, pt, ptlim); 503 diff /= 60; 504 pt = _conv((diff/60)*100 + diff%60, 505 "%04d", pt, ptlim); 506 } 507 continue; 508 #if 0 509 case '+': 510 pt = _fmt(Locale->date_fmt, t, pt, ptlim, 511 warnp); 512 continue; 513 #endif 514 case '%': 515 /* 516 ** X311J/88-090 (4.12.3.5): if conversion char is 517 ** undefined, behavior is undefined. Print out the 518 ** character itself as printf(3) also does. 519 */ 520 default: 521 break; 522 } 523 } 524 if (pt == ptlim) 525 break; 526 *pt++ = *format; 527 } 528 return pt; 529 } 530 531 static char * 532 _conv(n, format, pt, ptlim) 533 const int n; 534 const char * const format; 535 char * const pt; 536 const char * const ptlim; 537 { 538 char buf[INT_STRLEN_MAXIMUM(int) + 1]; 539 540 (void) sprintf(buf, format, n); 541 return _add(buf, pt, ptlim); 542 } 543 544 static char * 545 _add(str, pt, ptlim) 546 const char * str; 547 char * pt; 548 const char * const ptlim; 549 { 550 while (pt < ptlim && (*pt = *str++) != '\0') 551 ++pt; 552 return pt; 553 } 554
Indexes created Thu Sep 25 16:09:42 GMT 2025