lib/libc/time/strftime.c

   1 /*      $NetBSD: strftime.c,v 1.29 2013/09/20 19:06:54 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 static char     elsieid[] = "@(#)strftime.c     8.3";
   8 #else
   9 __RCSID("$NetBSD: strftime.c,v 1.29 2013/09/20 19:06:54 christos Exp $");
  10 #endif
  11 #endif /* LIBC_SCCS and not lint */
  12
  13 #include "namespace.h"
  14
  15 #include <stddef.h>
  16 #include <locale.h>
  17 #include "setlocale_local.h"
  18
  19 /*
  20 ** Based on the UCB version with the copyright notice and sccsid
  21 ** appearing below.
  22 **
  23 ** This is ANSIish only when "multibyte character == plain character".
  24 */
  25
  26 #include "private.h"
  27
  28 /*
  29 ** We don't use these extensions in strftime operation even when
  30 ** supported by the local tzcode configuration.  A strictly
  31 ** conforming C application may leave them in undefined state.
  32 */
  33
  34 #ifdef _LIBC
  35 #undef TM_ZONE
  36 #undef TM_GMTOFF
  37 #endif
  38
  39 /*
  40 ** Copyright (c) 1989, 1993
  41 **      The Regents of the University of California.  All rights reserved.
  42 **
  43 ** Redistribution and use in source and binary forms, with or without
  44 ** modification, are permitted provided that the following conditions
  45 ** are met:
  46 ** 1. Redistributions of source code must retain the above copyright
  47 **    notice, this list of conditions and the following disclaimer.
  48 ** 2. Redistributions in binary form must reproduce the above copyright
  49 **    notice, this list of conditions and the following disclaimer in the
  50 **    documentation and/or other materials provided with the distribution.
  51 ** 3. All advertising materials mentioning features or use of this software
  52 **    must display the following acknowledgement:
  53 **      This product includes software developed by the University of
  54 **      California, Berkeley and its contributors.
  55 ** 4. Neither the name of the University nor the names of its contributors
  56 **    may be used to endorse or promote products derived from this software
  57 **    without specific prior written permission.
  58 **
  59 ** THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  60 ** ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  61 ** IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  62 ** ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  63 ** FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  64 ** DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  65 ** OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  66 ** HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  67 ** LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  68 ** OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  69 ** SUCH DAMAGE.
  70 */
  71
  72 #ifndef LIBC_SCCS
  73 #ifndef lint
  74 static const char       sccsid[] = "@(#)strftime.c      5.4 (Berkeley) 3/14/89";
  75 #endif /* !defined lint */
  76 #endif /* !defined LIBC_SCCS */
  77
  78 #include "tzfile.h"
  79 #include "fcntl.h"
  80 #include "locale.h"
  81
  82 #ifdef __weak_alias
  83 __weak_alias(strftime_l, _strftime_l)
  84 __weak_alias(strftime_lz, _strftime_lz)
  85 __weak_alias(strftime_z, _strftime_z)
  86 #endif
  87
  88 #include "sys/localedef.h"
  89 #define _TIME_LOCALE(loc) \
  90     ((_TimeLocale *)((loc)->part_impl[(size_t)LC_TIME]))
  91 #define c_fmt   d_t_fmt
  92
  93 static char *   _add(const char *, char *, const char *);
  94 static char *   _conv(int, const char *, char *, const char *);
  95 static char *   _fmt(const timezone_t, const char *, const struct tm *, char *,
  96                         const char *, int *, locale_t);
  97 static char *   _yconv(int, int, int, int, char *, const char *);
  98
  99 extern char *   tzname[];
 100
 101 #ifndef YEAR_2000_NAME
 102 #define YEAR_2000_NAME  "CHECK_STRFTIME_FORMATS_FOR_TWO_DIGIT_YEARS"
 103 #endif /* !defined YEAR_2000_NAME */
 104
 105 #define IN_NONE 0
 106 #define IN_SOME 1
 107 #define IN_THIS 2
 108 #define IN_ALL  3
 109
 110 size_t
 111 strftime_z(const timezone_t sp, char * __restrict s, size_t maxsize,
 112     const char * __restrict format, const struct tm * __restrict t)
 113 {
 114         return strftime_lz(sp, s, maxsize, format, t, _current_locale());
 115 }
 116
 117 size_t
 118 strftime_lz(const timezone_t sp, char *const s, const size_t maxsize,
 119     const char *const format, const struct tm *const t, locale_t loc)
 120 {
 121         char *  p;
 122         int     warn;
 123
 124         warn = IN_NONE;
 125         p = _fmt(sp, ((format == NULL) ? "%c" : format), t, s, s + maxsize,
 126             &warn, loc);
 127 #ifndef NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU
 128         if (warn != IN_NONE && getenv(YEAR_2000_NAME) != NULL) {
 129                 (void) fprintf(stderr, "\n");
 130                 if (format == NULL)
 131                         (void) fprintf(stderr, "NULL strftime format ");
 132                 else    (void) fprintf(stderr, "strftime format \"%s\" ",
 133                                 format);
 134                 (void) fprintf(stderr, "yields only two digits of years in ");
 135                 if (warn == IN_SOME)
 136                         (void) fprintf(stderr, "some locales");
 137                 else if (warn == IN_THIS)
 138                         (void) fprintf(stderr, "the current locale");
 139                 else    (void) fprintf(stderr, "all locales");
 140                 (void) fprintf(stderr, "\n");
 141         }
 142 #endif /* !defined NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU */
 143         if (p == s + maxsize)
 144                 return 0;
 145         *p = '\0';
 146         return p - s;
 147 }
 148
 149 static char *
 150 _fmt(const timezone_t sp, const char *format, const struct tm *const t,
 151         char *pt, const char *const ptlim, int *warnp, locale_t loc)
 152 {
 153         for ( ; *format; ++format) {
 154                 if (*format == '%') {
 155 label:
 156                         switch (*++format) {
 157                         case '\0':
 158                                 --format;
 159                                 break;
 160                         case 'A':
 161                                 pt = _add((t->tm_wday < 0 ||
 162                                         t->tm_wday >= DAYSPERWEEK) ?
 163                                         "?" : _TIME_LOCALE(loc)->day[t->tm_wday],
 164                                         pt, ptlim);
 165                                 continue;
 166                         case 'a':
 167                                 pt = _add((t->tm_wday < 0 ||
 168                                         t->tm_wday >= DAYSPERWEEK) ?
 169                                         "?" : _TIME_LOCALE(loc)->abday[t->tm_wday],
 170                                         pt, ptlim);
 171                                 continue;
 172                         case 'B':
 173                                 pt = _add((t->tm_mon < 0 ||
 174                                         t->tm_mon >= MONSPERYEAR) ?
 175                                         "?" : _TIME_LOCALE(loc)->mon[t->tm_mon],
 176                                         pt, ptlim);
 177                                 continue;
 178                         case 'b':
 179                         case 'h':
 180                                 pt = _add((t->tm_mon < 0 ||
 181                                         t->tm_mon >= MONSPERYEAR) ?
 182                                         "?" : _TIME_LOCALE(loc)->abmon[t->tm_mon],
 183                                         pt, ptlim);
 184                                 continue;
 185                         case 'C':
 186                                 /*
 187                                 ** %C used to do a...
 188                                 **      _fmt("%a %b %e %X %Y", t);
 189                                 ** ...whereas now POSIX 1003.2 calls for
 190                                 ** something completely different.
 191                                 ** (ado, 1993-05-24)
 192                                 */
 193                                 pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 0,
 194                                         pt, ptlim);
 195                                 continue;
 196                         case 'c':
 197                                 {
 198                                 int warn2 = IN_SOME;
 199
 200                                 pt = _fmt(sp, _TIME_LOCALE(loc)->c_fmt, t, pt,
 201                                     ptlim, &warn2, loc);
 202                                 if (warn2 == IN_ALL)
 203                                         warn2 = IN_THIS;
 204                                 if (warn2 > *warnp)
 205                                         *warnp = warn2;
 206                                 }
 207                                 continue;
 208                         case 'D':
 209                                 pt = _fmt(sp, "%m/%d/%y", t, pt, ptlim, warnp,
 210                                     loc);
 211                                 continue;
 212                         case 'd':
 213                                 pt = _conv(t->tm_mday, "%02d", pt, ptlim);
 214                                 continue;
 215                         case 'E':
 216                         case 'O':
 217                                 /*
 218                                 ** C99 locale modifiers.
 219                                 ** The sequences
 220                                 **      %Ec %EC %Ex %EX %Ey %EY
 221                                 **      %Od %oe %OH %OI %Om %OM
 222                                 **      %OS %Ou %OU %OV %Ow %OW %Oy
 223                                 ** are supposed to provide alternate
 224                                 ** representations.
 225                                 */
 226                                 goto label;
 227                         case 'e':
 228                                 pt = _conv(t->tm_mday, "%2d", pt, ptlim);
 229                                 continue;
 230                         case 'F':
 231                                 pt = _fmt(sp, "%Y-%m-%d", t, pt, ptlim, warnp,
 232                                     loc);
 233                                 continue;
 234                         case 'H':
 235                                 pt = _conv(t->tm_hour, "%02d", pt, ptlim);
 236                                 continue;
 237                         case 'I':
 238                                 pt = _conv((t->tm_hour % 12) ?
 239                                         (t->tm_hour % 12) : 12,
 240                                         "%02d", pt, ptlim);
 241                                 continue;
 242                         case 'j':
 243                                 pt = _conv(t->tm_yday + 1, "%03d", pt, ptlim);
 244                                 continue;
 245                         case 'k':
 246                                 /*
 247                                 ** This used to be...
 248                                 **      _conv(t->tm_hour % 12 ?
 249                                 **              t->tm_hour % 12 : 12, 2, ' ');
 250                                 ** ...and has been changed to the below to
 251                                 ** match SunOS 4.1.1 and Arnold Robbins'
 252                                 ** strftime version 3.0. That is, "%k" and
 253                                 ** "%l" have been swapped.
 254                                 ** (ado, 1993-05-24)
 255                                 */
 256                                 pt = _conv(t->tm_hour, "%2d", pt, ptlim);
 257                                 continue;
 258 #ifdef KITCHEN_SINK
 259                         case 'K':
 260                                 /*
 261                                 ** After all this time, still unclaimed!
 262                                 */
 263                                 pt = _add("kitchen sink", pt, ptlim);
 264                                 continue;
 265 #endif /* defined KITCHEN_SINK */
 266                         case 'l':
 267                                 /*
 268                                 ** This used to be...
 269                                 **      _conv(t->tm_hour, 2, ' ');
 270                                 ** ...and has been changed to the below to
 271                                 ** match SunOS 4.1.1 and Arnold Robbin's
 272                                 ** strftime version 3.0. That is, "%k" and
 273                                 ** "%l" have been swapped.
 274                                 ** (ado, 1993-05-24)
 275                                 */
 276                                 pt = _conv((t->tm_hour % 12) ?
 277                                         (t->tm_hour % 12) : 12,
 278                                         "%2d", pt, ptlim);
 279                                 continue;
 280                         case 'M':
 281                                 pt = _conv(t->tm_min, "%02d", pt, ptlim);
 282                                 continue;
 283                         case 'm':
 284                                 pt = _conv(t->tm_mon + 1, "%02d", pt, ptlim);
 285                                 continue;
 286                         case 'n':
 287                                 pt = _add("\n", pt, ptlim);
 288                                 continue;
 289                         case 'p':
 290                                 pt = _add((t->tm_hour >= (HOURSPERDAY / 2)) ?
 291                                         _TIME_LOCALE(loc)->am_pm[1] :
 292                                         _TIME_LOCALE(loc)->am_pm[0],
 293                                         pt, ptlim);
 294                                 continue;
 295                         case 'R':
 296                                 pt = _fmt(sp, "%H:%M", t, pt, ptlim, warnp,
 297                                     loc);
 298                                 continue;
 299                         case 'r':
 300                                 pt = _fmt(sp, _TIME_LOCALE(loc)->t_fmt_ampm, t,
 301                                     pt, ptlim, warnp, loc);
 302                                 continue;
 303                         case 'S':
 304                                 pt = _conv(t->tm_sec, "%02d", pt, ptlim);
 305                                 continue;
 306                         case 's':
 307                                 {
 308                                         struct tm       tm;
 309                                         char            buf[INT_STRLEN_MAXIMUM(
 310                                                                 time_t) + 1];
 311                                         time_t          mkt;
 312
 313                                         tm = *t;
 314                                         mkt = mktime(&tm);
 315                                         /* CONSTCOND */
 316                                         if (TYPE_SIGNED(time_t))
 317                                                 (void)snprintf(buf, sizeof(buf),
 318                                                     "%jd", (intmax_t) mkt);
 319                                         else    (void)snprintf(buf, sizeof(buf),
 320                                                     "%ju", (uintmax_t) mkt);
 321                                         pt = _add(buf, pt, ptlim);
 322                                 }
 323                                 continue;
 324                         case 'T':
 325                                 pt = _fmt(sp, "%H:%M:%S", t, pt, ptlim, warnp,
 326                                     loc);
 327                                 continue;
 328                         case 't':
 329                                 pt = _add("\t", pt, ptlim);
 330                                 continue;
 331                         case 'U':
 332                                 pt = _conv((t->tm_yday + DAYSPERWEEK -
 333                                         t->tm_wday) / DAYSPERWEEK,
 334                                         "%02d", pt, ptlim);
 335                                 continue;
 336                         case 'u':
 337                                 /*
 338                                 ** From Arnold Robbins' strftime version 3.0:
 339                                 ** "ISO 8601: Weekday as a decimal number
 340                                 ** [1 (Monday) - 7]"
 341                                 ** (ado, 1993-05-24)
 342                                 */
 343                                 pt = _conv((t->tm_wday == 0) ?
 344                                         DAYSPERWEEK : t->tm_wday,
 345                                         "%d", pt, ptlim);
 346                                 continue;
 347                         case 'V':       /* ISO 8601 week number */
 348                         case 'G':       /* ISO 8601 year (four digits) */
 349                         case 'g':       /* ISO 8601 year (two digits) */
 350 /*
 351 ** From Arnold Robbins' strftime version 3.0: "the week number of the
 352 ** year (the first Monday as the first day of week 1) as a decimal number
 353 ** (01-53)."
 354 ** (ado, 1993-05-24)
 355 **
 356 ** From "http://www.ft.uni-erlangen.de/~mskuhn/iso-time.html" by Markus Kuhn:
 357 ** "Week 01 of a year is per definition the first week which has the
 358 ** Thursday in this year, which is equivalent to the week which contains
 359 ** the fourth day of January. In other words, the first week of a new year
 360 ** is the week which has the majority of its days in the new year. Week 01
 361 ** might also contain days from the previous year and the week before week
 362 ** 01 of a year is the last week (52 or 53) of the previous year even if
 363 ** it contains days from the new year. A week starts with Monday (day 1)
 364 ** and ends with Sunday (day 7). For example, the first week of the year
 365 ** 1997 lasts from 1996-12-30 to 1997-01-05..."
 366 ** (ado, 1996-01-02)
 367 */
 368                                 {
 369                                         int     year;
 370                                         int     base;
 371                                         int     yday;
 372                                         int     wday;
 373                                         int     w;
 374
 375                                         year = t->tm_year;
 376                                         base = TM_YEAR_BASE;
 377                                         yday = t->tm_yday;
 378                                         wday = t->tm_wday;
 379                                         for ( ; ; ) {
 380                                                 int     len;
 381                                                 int     bot;
 382                                                 int     top;
 383
 384                                                 len = isleap_sum(year, base) ?
 385                                                         DAYSPERLYEAR :
 386                                                         DAYSPERNYEAR;
 387                                                 /*
 388                                                 ** What yday (-3 ... 3) does
 389                                                 ** the ISO year begin on?
 390                                                 */
 391                                                 bot = ((yday + 11 - wday) %
 392                                                         DAYSPERWEEK) - 3;
 393                                                 /*
 394                                                 ** What yday does the NEXT
 395                                                 ** ISO year begin on?
 396                                                 */
 397                                                 top = bot -
 398                                                         (len % DAYSPERWEEK);
 399                                                 if (top < -3)
 400                                                         top += DAYSPERWEEK;
 401                                                 top += len;
 402                                                 if (yday >= top) {
 403                                                         ++base;
 404                                                         w = 1;
 405                                                         break;
 406                                                 }
 407                                                 if (yday >= bot) {
 408                                                         w = 1 + ((yday - bot) /
 409                                                                 DAYSPERWEEK);
 410                                                         break;
 411                                                 }
 412                                                 --base;
 413                                                 yday += isleap_sum(year, base) ?
 414                                                         DAYSPERLYEAR :
 415                                                         DAYSPERNYEAR;
 416                                         }
 417 #ifdef XPG4_1994_04_09
 418                                         if ((w == 52 &&
 419                                                 t->tm_mon == TM_JANUARY) ||
 420                                                 (w == 1 &&
 421                                                 t->tm_mon == TM_DECEMBER))
 422                                                         w = 53;
 423 #endif /* defined XPG4_1994_04_09 */
 424                                         if (*format == 'V')
 425                                                 pt = _conv(w, "%02d",
 426                                                         pt, ptlim);
 427                                         else if (*format == 'g') {
 428                                                 *warnp = IN_ALL;
 429                                                 pt = _yconv(year, base, 0, 1,
 430                                                         pt, ptlim);
 431                                         } else  pt = _yconv(year, base, 1, 1,
 432                                                         pt, ptlim);
 433                                 }
 434                                 continue;
 435                         case 'v':
 436                                 /*
 437                                 ** From Arnold Robbins' strftime version 3.0:
 438                                 ** "date as dd-bbb-YYYY"
 439                                 ** (ado, 1993-05-24)
 440                                 */
 441                                 pt = _fmt(sp, "%e-%b-%Y", t, pt, ptlim, warnp,
 442                                     loc);
 443                                 continue;
 444                         case 'W':
 445                                 pt = _conv((t->tm_yday + DAYSPERWEEK -
 446                                         (t->tm_wday ?
 447                                         (t->tm_wday - 1) :
 448                                         (DAYSPERWEEK - 1))) / DAYSPERWEEK,
 449                                         "%02d", pt, ptlim);
 450                                 continue;
 451                         case 'w':
 452                                 pt = _conv(t->tm_wday, "%d", pt, ptlim);
 453                                 continue;
 454                         case 'X':
 455                                 pt = _fmt(sp, _TIME_LOCALE(loc)->t_fmt, t, pt,
 456                                     ptlim, warnp, loc);
 457                                 continue;
 458                         case 'x':
 459                                 {
 460                                 int     warn2 = IN_SOME;
 461
 462                                 pt = _fmt(sp, _TIME_LOCALE(loc)->d_fmt, t, pt,
 463                                     ptlim, &warn2, loc);
 464                                 if (warn2 == IN_ALL)
 465                                         warn2 = IN_THIS;
 466                                 if (warn2 > *warnp)
 467                                         *warnp = warn2;
 468                                 }
 469                                 continue;
 470                         case 'y':
 471                                 *warnp = IN_ALL;
 472                                 pt = _yconv(t->tm_year, TM_YEAR_BASE, 0, 1,
 473                                         pt, ptlim);
 474                                 continue;
 475                         case 'Y':
 476                                 pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 1,
 477                                         pt, ptlim);
 478                                 continue;
 479                         case 'Z':
 480 #ifdef TM_ZONE
 481                                 if (t->TM_ZONE != NULL)
 482                                         pt = _add(t->TM_ZONE, pt, ptlim);
 483                                 else
 484 #endif /* defined TM_ZONE */
 485                                 if (t->tm_isdst >= 0)
 486                                         pt = _add((sp ?
 487                                             tzgetname(sp, t->tm_isdst) :
 488                                             tzname[t->tm_isdst != 0]),
 489                                             pt, ptlim);
 490                                 /*
 491                                 ** C99 says that %Z must be replaced by the
 492                                 ** empty string if the time zone is not
 493                                 ** determinable.
 494                                 */
 495                                 continue;
 496                         case 'z':
 497                                 {
 498                                 int             diff;
 499                                 char const *    sign;
 500
 501                                 if (t->tm_isdst < 0)
 502                                         continue;
 503 #ifdef TM_GMTOFF
 504                                 diff = (int)t->TM_GMTOFF;
 505 #else /* !defined TM_GMTOFF */
 506                                 /*
 507                                 ** C99 says that the UT offset must
 508                                 ** be computed by looking only at
 509                                 ** tm_isdst. This requirement is
 510                                 ** incorrect, since it means the code
 511                                 ** must rely on magic (in this case
 512                                 ** altzone and timezone), and the
 513                                 ** magic might not have the correct
 514                                 ** offset. Doing things correctly is
 515                                 ** tricky and requires disobeying C99;
 516                                 ** see GNU C strftime for details.
 517                                 ** For now, punt and conform to the
 518                                 ** standard, even though it's incorrect.
 519                                 **
 520                                 ** C99 says that %z must be replaced by the
 521                                 ** empty string if the time zone is not
 522                                 ** determinable, so output nothing if the
 523                                 ** appropriate variables are not available.
 524                                 */
 525 #ifndef STD_INSPIRED
 526                                 if (t->tm_isdst == 0)
 527 #ifdef USG_COMPAT
 528                                         diff = -timezone;
 529 #else /* !defined USG_COMPAT */
 530                                         continue;
 531 #endif /* !defined USG_COMPAT */
 532                                 else
 533 #ifdef ALTZONE
 534                                         diff = -altzone;
 535 #else /* !defined ALTZONE */
 536                                         continue;
 537 #endif /* !defined ALTZONE */
 538 #else /* defined STD_INSPIRED */
 539                                 {
 540                                         struct tm tmp;
 541                                         time_t lct, gct;
 542
 543                                         /*
 544                                         ** Get calendar time from t
 545                                         ** being treated as local.
 546                                         */
 547                                         tmp = *t; /* mktime discards const */
 548                                         lct = mktime(&tmp);
 549
 550                                         if (lct == (time_t)-1)
 551                                                 continue;
 552
 553                                         /*
 554                                         ** Get calendar time from t
 555                                         ** being treated as GMT.
 556                                         **/
 557                                         tmp = *t; /* mktime discards const */
 558                                         gct = timegm(&tmp);
 559
 560                                         if (gct == (time_t)-1)
 561                                                 continue;
 562
 563                                         /* LINTED difference will fit int */
 564                                         diff = (intmax_t)gct - (intmax_t)lct;
 565                                 }
 566 #endif /* defined STD_INSPIRED */
 567 #endif /* !defined TM_GMTOFF */
 568                                 if (diff < 0) {
 569                                         sign = "-";
 570                                         diff = -diff;
 571                                 } else  sign = "+";
 572                                 pt = _add(sign, pt, ptlim);
 573                                 diff /= SECSPERMIN;
 574                                 diff = (diff / MINSPERHOUR) * 100 +
 575                                         (diff % MINSPERHOUR);
 576                                 pt = _conv(diff, "%04d", pt, ptlim);
 577                                 }
 578                                 continue;
 579 #if defined(__minix)
 580                         case '+':
 581                                 pt = _fmt(sp, _TIME_LOCALE(loc)->c_fmt, t, pt, ptlim, warnp, loc);
 582                                 continue;
 583 #endif /* defined(__minix) */
 584 #if 0
 585                         case '+':
 586                                 pt = _fmt(sp, _TIME_LOCALE(loc)->date_fmt, t,
 587                                     pt, ptlim, warnp, loc);
 588                                 continue;
 589 #endif
 590                         case '%':
 591                         /*
 592                         ** X311J/88-090 (4.12.3.5): if conversion char is
 593                         ** undefined, behavior is undefined. Print out the
 594                         ** character itself as printf(3) also does.
 595                         */
 596                         default:
 597                                 break;
 598                         }
 599                 }
 600                 if (pt == ptlim)
 601                         break;
 602                 *pt++ = *format;
 603         }
 604         return pt;
 605 }
 606
 607 size_t
 608 strftime(char * const s, const size_t maxsize,
 609     const char * const format, const struct tm * const  t)
 610 {
 611         tzset();
 612         return strftime_z(NULL, s, maxsize, format, t);
 613 }
 614
 615 size_t
 616 strftime_l(char * __restrict s, size_t maxsize, const char * __restrict format,
 617     const struct tm * __restrict t, locale_t loc)
 618 {
 619         tzset();
 620         return strftime_lz(NULL, s, maxsize, format, t, loc);
 621 }
 622
 623 static char *
 624 _conv(const int n, const char *const format, char *const pt,
 625     const char *const ptlim)
 626 {
 627         char    buf[INT_STRLEN_MAXIMUM(int) + 1];
 628
 629         (void) snprintf(buf, sizeof(buf), format, n);
 630         return _add(buf, pt, ptlim);
 631 }
 632
 633 static char *
 634 _add(const char *str, char *pt, const char *const ptlim)
 635 {
 636         while (pt < ptlim && (*pt = *str++) != '\0')
 637                 ++pt;
 638         return pt;
 639 }
 640
 641 /*
 642 ** POSIX and the C Standard are unclear or inconsistent about
 643 ** what %C and %y do if the year is negative or exceeds 9999.
 644 ** Use the convention that %C concatenated with %y yields the
 645 ** same output as %Y, and that %Y contains at least 4 bytes,
 646 ** with more only if necessary.
 647 */
 648
 649 static char *
 650 _yconv(const int a, const int b, const int convert_top, const int convert_yy,
 651     char *pt, const char *const ptlim)
 652 {
 653         int     lead;
 654         int     trail;
 655
 656 #define DIVISOR 100
 657         trail = a % DIVISOR + b % DIVISOR;
 658         lead = a / DIVISOR + b / DIVISOR + trail / DIVISOR;
 659         trail %= DIVISOR;
 660         if (trail < 0 && lead > 0) {
 661                 trail += DIVISOR;
 662                 --lead;
 663         } else if (lead < 0 && trail > 0) {
 664                 trail -= DIVISOR;
 665                 ++lead;
 666         }
 667         if (convert_top) {
 668                 if (lead == 0 && trail < 0)
 669                         pt = _add("-0", pt, ptlim);
 670                 else    pt = _conv(lead, "%02d", pt, ptlim);
 671         }
 672         if (convert_yy)
 673                 pt = _conv(((trail < 0) ? -trail : trail), "%02d", pt, ptlim);
 674         return pt;
 675 }
 676
 677 #ifdef LOCALE_HOME
 678 static struct lc_time_T *
 679 _loc(void)
 680 {
 681         static const char       locale_home[] = LOCALE_HOME;
 682         static const char       lc_time[] = "LC_TIME";
 683         static char *           locale_buf;
 684
 685         int                     fd;
 686         int                     oldsun; /* "...ain't got nothin' to do..." */
 687         char *                  lbuf;
 688         char *                  name;
 689         char *                  p;
 690         const char **           ap;
 691         const char *            plim;
 692         char                    filename[FILENAME_MAX];
 693         struct stat             st;
 694         size_t                  namesize;
 695         size_t                  bufsize;
 696
 697         /*
 698         ** Use localebuf.mon[0] to signal whether locale is already set up.
 699         */
 700         if (localebuf.mon[0])
 701                 return &localebuf;
 702         name = setlocale(LC_TIME, NULL);
 703         if (name == NULL || *name == '\0')
 704                 goto no_locale;
 705         /*
 706         ** If the locale name is the same as our cache, use the cache.
 707         */
 708         lbuf = locale_buf;
 709         if (lbuf != NULL && strcmp(name, lbuf) == 0) {
 710                 p = lbuf;
 711                 for (ap = (const char **) &localebuf;
 712                         ap < (const char **) (&localebuf + 1);
 713                                 ++ap)
 714                                         *ap = p += strlen(p) + 1;
 715                 return &localebuf;
 716         }
 717         /*
 718         ** Slurp the locale file into the cache.
 719         */
 720         namesize = strlen(name) + 1;
 721         if (sizeof filename <
 722                 ((sizeof locale_home) + namesize + (sizeof lc_time)))
 723                         goto no_locale;
 724         oldsun = 0;
 725         (void) sprintf(filename, "%s/%s/%s", locale_home, name, lc_time);
 726         fd = open(filename, O_RDONLY);
 727         if (fd < 0) {
 728                 /*
 729                 ** Old Sun systems have a different naming and data convention.
 730                 */
 731                 oldsun = 1;
 732                 (void) sprintf(filename, "%s/%s/%s", locale_home,
 733                         lc_time, name);
 734                 fd = open(filename, O_RDONLY);
 735                 if (fd < 0)
 736                         goto no_locale;
 737         }
 738         if (fstat(fd, &st) != 0)
 739                 goto bad_locale;
 740         if (st.st_size <= 0)
 741                 goto bad_locale;
 742         bufsize = namesize + st.st_size;
 743         locale_buf = NULL;
 744         lbuf = (lbuf == NULL) ? malloc(bufsize) : realloc(lbuf, bufsize);
 745         if (lbuf == NULL)
 746                 goto bad_locale;
 747         (void) strcpy(lbuf, name);
 748         p = lbuf + namesize;
 749         plim = p + st.st_size;
 750         if (read(fd, p, (size_t) st.st_size) != st.st_size)
 751                 goto bad_lbuf;
 752         if (close(fd) != 0)
 753                 goto bad_lbuf;
 754         /*
 755         ** Parse the locale file into localebuf.
 756         */
 757         if (plim[-1] != '\n')
 758                 goto bad_lbuf;
 759         for (ap = (const char **) &localebuf;
 760                 ap < (const char **) (&localebuf + 1);
 761                         ++ap) {
 762                                 if (p == plim)
 763                                         goto bad_lbuf;
 764                                 *ap = p;
 765                                 while (*p != '\n')
 766                                         ++p;
 767                                 *p++ = '\0';
 768         }
 769         if (oldsun) {
 770                 /*
 771                 ** SunOS 4 used an obsolescent format; see localdtconv(3).
 772                 ** c_fmt had the ``short format for dates and times together''
 773                 ** (SunOS 4 date, "%a %b %e %T %Z %Y" in the C locale);
 774                 ** date_fmt had the ``long format for dates''
 775                 ** (SunOS 4 strftime %C, "%A, %B %e, %Y" in the C locale).
 776                 ** Discard the latter in favor of the former.
 777                 */
 778                 localebuf.date_fmt = localebuf.c_fmt;
 779         }
 780         /*
 781         ** Record the successful parse in the cache.
 782         */
 783         locale_buf = lbuf;
 784
 785         return &localebuf;
 786
 787 bad_lbuf:
 788         free(lbuf);
 789 bad_locale:
 790         (void) close(fd);
 791 no_locale:
 792         localebuf = C_time_locale;
 793         locale_buf = NULL;
 794         return &localebuf;
 795 }
 796 #endif /* defined LOCALE_HOME */