lib/strftime.c

   1 /* Copyright (C) 1991,92,93,94,95,96,97,98,99 Free Software Foundation, Inc.
   2
   3    NOTE: The canonical source of this file is maintained with the GNU C Library.
   4    Bugs can be reported to bug-glibc@prep.ai.mit.edu.
   5
   6    This program is free software; you can redistribute it and/or modify it
   7    under the terms of the GNU General Public License as published by the
   8    Free Software Foundation; either version 2, or (at your option) any
   9    later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    Library General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  19    USA.  */
  20
  21 #ifdef HAVE_CONFIG_H
  22 # include <config.h>
  23 #endif
  24
  25 #ifdef _LIBC
  26 # define HAVE_LIMITS_H 1
  27 # define HAVE_MBLEN 1
  28 # define HAVE_MBRLEN 1
  29 # define HAVE_STRUCT_ERA_ENTRY 1
  30 # define HAVE_TM_GMTOFF 1
  31 # define HAVE_TM_ZONE 1
  32 # define HAVE_TZNAME 1
  33 # define HAVE_TZSET 1
  34 # define MULTIBYTE_IS_FORMAT_SAFE 1
  35 # define STDC_HEADERS 1
  36 # include "../locale/localeinfo.h"
  37 #endif
  38
  39 #if defined emacs && !defined HAVE_BCOPY
  40 # define HAVE_MEMCPY 1
  41 #endif
  42
  43 #include <ctype.h>
  44 #include <sys/types.h>          /* Some systems define `time_t' here.  */
  45
  46 #ifdef TIME_WITH_SYS_TIME
  47 # include <sys/time.h>
  48 # include <time.h>
  49 #else
  50 # ifdef HAVE_SYS_TIME_H
  51 #  include <sys/time.h>
  52 # else
  53 #  include <time.h>
  54 # endif
  55 #endif
  56 #if HAVE_TZNAME
  57 extern char *tzname[];
  58 #endif
  59
  60 /* Do multibyte processing if multibytes are supported, unless
  61    multibyte sequences are safe in formats.  Multibyte sequences are
  62    safe if they cannot contain byte sequences that look like format
  63    conversion specifications.  The GNU C Library uses UTF8 multibyte
  64    encoding, which is safe for formats, but strftime.c can be used
  65    with other C libraries that use unsafe encodings.  */
  66 #define DO_MULTIBYTE (HAVE_MBLEN && ! MULTIBYTE_IS_FORMAT_SAFE)
  67
  68 #if DO_MULTIBYTE
  69 # if HAVE_MBRLEN
  70 #  include <wchar.h>
  71 # else
  72    /* Simulate mbrlen with mblen as best we can.  */
  73 #  define mbstate_t int
  74 #  define mbrlen(s, n, ps) mblen (s, n)
  75 #  define mbsinit(ps) (*(ps) == 0)
  76 # endif
  77   static const mbstate_t mbstate_zero;
  78 #endif
  79
  80 #if HAVE_LIMITS_H
  81 # include <limits.h>
  82 #endif
  83
  84 #if STDC_HEADERS
  85 # include <stddef.h>
  86 # include <stdlib.h>
  87 # include <string.h>
  88 #else
  89 # ifndef HAVE_MEMCPY
  90 #  define memcpy(d, s, n) bcopy ((s), (d), (n))
  91 # endif
  92 #endif
  93
  94 #ifdef COMPILE_WIDE
  95 # include <endian.h>
  96 # define CHAR_T wchar_t
  97 # define UCHAR_T unsigned int
  98 # define L_(Str) L##Str
  99 # define NLW(Sym) _NL_W##Sym
 100
 101 # define MEMCPY(d, s, n) wmemcpy (d, s, n)
 102 # define STRLEN(s) wcslen (s)
 103
 104 #else
 105 # define CHAR_T char
 106 # define UCHAR_T unsigned char
 107 # define L_(Str) Str
 108 # define NLW(Sym) Sym
 109
 110 # if !defined STDC_HEADERS && !defined HAVE_MEMCPY
 111 #  define MEMCPY(d, s, n) bcopy ((s), (d), (n))
 112 # else
 113 #  define MEMCPY(d, s, n) memcpy ((d), (s), (n))
 114 # endif
 115 # define STRLEN(s) strlen (s)
 116
 117 # ifdef _LIBC
 118 #  define MEMPCPY(d, s, n) __mempcpy (d, s, n)
 119 # else
 120 #  ifndef HAVE_MEMPCPY
 121 #   define MEMPCPY(d, s, n) ((void *) ((char *) memcpy (d, s, n) + (n)))
 122 #  endif
 123 # endif
 124 #endif
 125
 126 #ifndef __P
 127 # if defined __GNUC__ || (defined __STDC__ && __STDC__)
 128 #  define __P(args) args
 129 # else
 130 #  define __P(args) ()
 131 # endif  /* GCC.  */
 132 #endif  /* Not __P.  */
 133
 134 #ifndef PTR
 135 # ifdef __STDC__
 136 #  define PTR void *
 137 # else
 138 #  define PTR char *
 139 # endif
 140 #endif
 141
 142 #ifndef CHAR_BIT
 143 # define CHAR_BIT 8
 144 #endif
 145
 146 #ifndef NULL
 147 # define NULL 0
 148 #endif
 149
 150 #define TYPE_SIGNED(t) ((t) -1 < 0)
 151
 152 /* Bound on length of the string representing an integer value of type t.
 153    Subtract one for the sign bit if t is signed;
 154    302 / 1000 is log10 (2) rounded up;
 155    add one for integer division truncation;
 156    add one more for a minus sign if t is signed.  */
 157 #define INT_STRLEN_BOUND(t) \
 158  ((sizeof (t) * CHAR_BIT - TYPE_SIGNED (t)) * 302 / 1000 + 1 + TYPE_SIGNED (t))
 159
 160 #define TM_YEAR_BASE 1900
 161
 162 #ifndef __isleap
 163 /* Nonzero if YEAR is a leap year (every 4 years,
 164    except every 100th isn't, and every 400th is).  */
 165 # define __isleap(year) \
 166   ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0))
 167 #endif
 168
 169
 170 #ifdef _LIBC
 171 # define my_strftime_gmtime_r __gmtime_r
 172 # define my_strftime_localtime_r __localtime_r
 173 # define tzname __tzname
 174 # define tzset __tzset
 175 #else
 176
 177 /* If we're a strftime substitute in a GNU program, then prefer gmtime
 178    to gmtime_r, since many gmtime_r implementations are buggy.
 179    Similarly for localtime_r.  */
 180
 181 # if ! HAVE_TM_GMTOFF
 182 static struct tm *my_strftime_gmtime_r __P ((const time_t *, struct tm *));
 183 static struct tm *
 184 my_strftime_gmtime_r (t, tp)
 185      const time_t *t;
 186      struct tm *tp;
 187 {
 188   struct tm *l = gmtime (t);
 189   if (! l)
 190     return 0;
 191   *tp = *l;
 192   return tp;
 193 }
 194 # endif /* ! HAVE_TM_GMTOFF */
 195
 196 static struct tm *my_strftime_localtime_r __P ((const time_t *, struct tm *));
 197 static struct tm *
 198 my_strftime_localtime_r (t, tp)
 199      const time_t *t;
 200      struct tm *tp;
 201 {
 202   struct tm *l = localtime (t);
 203   if (! l)
 204     return 0;
 205   *tp = *l;
 206   return tp;
 207 }
 208 #endif /* ! defined _LIBC */
 209
 210
 211 #if !defined memset && !defined HAVE_MEMSET && !defined _LIBC
 212 /* Some systems lack the `memset' function and we don't want to
 213    introduce additional dependencies.  */
 214 /* The SGI compiler reportedly barfs on the trailing null
 215    if we use a string constant as the initializer.  28 June 1997, rms.  */
 216 static const CHAR_T spaces[16] = /* "                " */
 217 {
 218   L_(' '),L_(' '),L_(' '),L_(' '),L_(' '),L_(' '),L_(' '),L_(' '),
 219   L_(' '),L_(' '),L_(' '),L_(' '),L_(' '),L_(' '),L_(' '),L_(' ')
 220 };
 221 static const CHAR_T zeroes[16] = /* "0000000000000000" */
 222 {
 223   L_('0'),L_('0'),L_('0'),L_('0'),L_('0'),L_('0'),L_('0'),L_('0'),
 224   L_('0'),L_('0'),L_('0'),L_('0'),L_('0'),L_('0'),L_('0'),L_('0')
 225 };
 226
 227 # define memset_space(P, Len) \
 228   do {                                                                        \
 229     int _len = (Len);                                                         \
 230                                                                               \
 231     do                                                                        \
 232       {                                                                       \
 233         int _this = _len > 16 ? 16 : _len;                                    \
 234         (P) = MEMPCPY ((P), spaces, _this * sizeof (CHAR_T));                 \
 235         _len -= _this;                                                        \
 236       }                                                                       \
 237     while (_len > 0);                                                         \
 238   } while (0)
 239
 240 # define memset_zero(P, Len) \
 241   do {                                                                        \
 242     int _len = (Len);                                                         \
 243                                                                               \
 244     do                                                                        \
 245       {                                                                       \
 246         int _this = _len > 16 ? 16 : _len;                                    \
 247         (P) = MEMPCPY ((P), zeroes, _this * sizeof (CHAR_T));                 \
 248         _len -= _this;                                                        \
 249       }                                                                       \
 250     while (_len > 0);                                                         \
 251   } while (0)
 252 #else
 253 # ifdef COMPILE_WIDE
 254 #  define memset_space(P, Len) (wmemset ((P), L' ', (Len)), (P) += (Len))
 255 #  define memset_zero(P, Len) (wmemset ((P), L'0', (Len)), (P) += (Len))
 256 # else
 257 #  define memset_space(P, Len) (memset ((P), ' ', (Len)), (P) += (Len))
 258 #  define memset_zero(P, Len) (memset ((P), '0', (Len)), (P) += (Len))
 259 # endif
 260 #endif
 261
 262 #define add(n, f)                                                             \
 263   do                                                                          \
 264     {                                                                         \
 265       int _n = (n);                                                           \
 266       int _delta = width - _n;                                                \
 267       int _incr = _n + (_delta > 0 ? _delta : 0);                             \
 268       if (i + _incr >= maxsize)                                               \
 269         return 0;                                                             \
 270       if (p)                                                                  \
 271         {                                                                     \
 272           if (_delta > 0)                                                     \
 273             {                                                                 \
 274               if (pad == L_('0'))                                             \
 275                 memset_zero (p, _delta);                                      \
 276               else                                                            \
 277                 memset_space (p, _delta);                                     \
 278             }                                                                 \
 279           f;                                                                  \
 280           p += _n;                                                            \
 281         }                                                                     \
 282       i += _incr;                                                             \
 283     } while (0)
 284
 285 #define cpy(n, s) \
 286     add ((n),                                                                 \
 287          if (to_lowcase)                                                      \
 288            memcpy_lowcase (p, (s), _n);                                       \
 289          else if (to_uppcase)                                                 \
 290            memcpy_uppcase (p, (s), _n);                                       \
 291          else                                                                 \
 292            MEMCPY ((PTR) p, (PTR) (s), _n))
 293
 294 #ifdef COMPILE_WIDE
 295 # define widen(os, ws, l) \
 296   {                                                                           \
 297     mbstate_t __st;                                                           \
 298     const char *__s = os;                                                     \
 299     memset (&__st, '\0', sizeof (__st));                                      \
 300     l = __mbsrtowcs (NULL, &__s, 0, &__st);                                   \
 301     ws = alloca ((l + 1) * sizeof (wchar_t));                                 \
 302     (void) __mbsrtowcs (ws, &__s, l, &__st);                                  \
 303   }
 304 #endif
 305
 306
 307 #ifdef COMPILE_WIDE
 308 # define TOUPPER(Ch) towupper (Ch)
 309 # define TOLOWER(Ch) towlower (Ch)
 310 #else
 311 # ifdef _LIBC
 312 #  define TOUPPER(Ch) toupper (Ch)
 313 #  define TOLOWER(Ch) tolower (Ch)
 314 # else
 315 #  define TOUPPER(Ch) (islower (Ch) ? toupper (Ch) : (Ch))
 316 #  define TOLOWER(Ch) (isupper (Ch) ? tolower (Ch) : (Ch))
 317 # endif
 318 #endif
 319 /* We don't use `isdigit' here since the locale dependent
 320    interpretation is not what we want here.  We only need to accept
 321    the arabic digits in the ASCII range.  One day there is perhaps a
 322    more reliable way to accept other sets of digits.  */
 323 #define ISDIGIT(Ch) ((unsigned int) (Ch) - L_('0') <= 9)
 324
 325 static CHAR_T *memcpy_lowcase __P ((CHAR_T *dest, const CHAR_T *src,
 326                                     size_t len));
 327
 328 static CHAR_T *
 329 memcpy_lowcase (dest, src, len)
 330      CHAR_T *dest;
 331      const CHAR_T *src;
 332      size_t len;
 333 {
 334   while (len-- > 0)
 335     dest[len] = TOLOWER ((UCHAR_T) src[len]);
 336   return dest;
 337 }
 338
 339 static CHAR_T *memcpy_uppcase __P ((CHAR_T *dest, const CHAR_T *src,
 340                                     size_t len));
 341
 342 static CHAR_T *
 343 memcpy_uppcase (dest, src, len)
 344      CHAR_T *dest;
 345      const CHAR_T *src;
 346      size_t len;
 347 {
 348   while (len-- > 0)
 349     dest[len] = TOUPPER ((UCHAR_T) src[len]);
 350   return dest;
 351 }
 352
 353
 354 #if ! HAVE_TM_GMTOFF
 355 /* Yield the difference between *A and *B,
 356    measured in seconds, ignoring leap seconds.  */
 357 # define tm_diff ftime_tm_diff
 358 static int tm_diff __P ((const struct tm *, const struct tm *));
 359 static int
 360 tm_diff (a, b)
 361      const struct tm *a;
 362      const struct tm *b;
 363 {
 364   /* Compute intervening leap days correctly even if year is negative.
 365      Take care to avoid int overflow in leap day calculations,
 366      but it's OK to assume that A and B are close to each other.  */
 367   int a4 = (a->tm_year >> 2) + (TM_YEAR_BASE >> 2) - ! (a->tm_year & 3);
 368   int b4 = (b->tm_year >> 2) + (TM_YEAR_BASE >> 2) - ! (b->tm_year & 3);
 369   int a100 = a4 / 25 - (a4 % 25 < 0);
 370   int b100 = b4 / 25 - (b4 % 25 < 0);
 371   int a400 = a100 >> 2;
 372   int b400 = b100 >> 2;
 373   int intervening_leap_days = (a4 - b4) - (a100 - b100) + (a400 - b400);
 374   int years = a->tm_year - b->tm_year;
 375   int days = (365 * years + intervening_leap_days
 376               + (a->tm_yday - b->tm_yday));
 377   return (60 * (60 * (24 * days + (a->tm_hour - b->tm_hour))
 378                 + (a->tm_min - b->tm_min))
 379           + (a->tm_sec - b->tm_sec));
 380 }
 381 #endif /* ! HAVE_TM_GMTOFF */
 382
 383
 384
 385 /* The number of days from the first day of the first ISO week of this
 386    year to the year day YDAY with week day WDAY.  ISO weeks start on
 387    Monday; the first ISO week has the year's first Thursday.  YDAY may
 388    be as small as YDAY_MINIMUM.  */
 389 #define ISO_WEEK_START_WDAY 1 /* Monday */
 390 #define ISO_WEEK1_WDAY 4 /* Thursday */
 391 #define YDAY_MINIMUM (-366)
 392 static int iso_week_days __P ((int, int));
 393 #ifdef __GNUC__
 394 __inline__
 395 #endif
 396 static int
 397 iso_week_days (yday, wday)
 398      int yday;
 399      int wday;
 400 {
 401   /* Add enough to the first operand of % to make it nonnegative.  */
 402   int big_enough_multiple_of_7 = (-YDAY_MINIMUM / 7 + 2) * 7;
 403   return (yday
 404           - (yday - wday + ISO_WEEK1_WDAY + big_enough_multiple_of_7) % 7
 405           + ISO_WEEK1_WDAY - ISO_WEEK_START_WDAY);
 406 }
 407
 408
 409 #if !(defined _NL_CURRENT || HAVE_STRFTIME)
 410 static CHAR_T const weekday_name[][10] =
 411   {
 412     L_("Sunday"), L_("Monday"), L_("Tuesday"), L_("Wednesday"),
 413     L_("Thursday"), L_("Friday"), L_("Saturday")
 414   };
 415 static CHAR_T const month_name[][10] =
 416   {
 417     L_("January"), L_("February"), L_("March"), L_("April"), L_("May"),
 418     L_("June"), L_("July"), L_("August"), L_("September"), L_("October"),
 419     L_("November"), L_("December")
 420   };
 421 #endif
 422
 423
 424 #ifdef emacs
 425 # define my_strftime emacs_strftimeu
 426 # define ut_argument , ut
 427 # define ut_argument_spec int ut;
 428 # define ut_argument_spec_iso , int ut
 429 #else
 430 # ifdef COMPILE_WIDE
 431 #  define my_strftime wcsftime
 432 # else
 433 #  define my_strftime strftime
 434 # endif
 435 # define ut_argument
 436 # define ut_argument_spec
 437 # define ut_argument_spec_iso
 438 /* We don't have this information in general.  */
 439 # define ut 0
 440 #endif
 441
 442 #if !defined _LIBC && HAVE_TZNAME && HAVE_TZSET
 443   /* Solaris 2.5 tzset sometimes modifies the storage returned by localtime.
 444      Work around this bug by copying *tp before it might be munged.  */
 445   size_t _strftime_copytm __P ((char *, size_t, const char *,
 446                                 const struct tm * ut_argument_spec_iso));
 447   size_t
 448   my_strftime (s, maxsize, format, tp ut_argument)
 449       CHAR_T *s;
 450       size_t maxsize;
 451       const CHAR_T *format;
 452       const struct tm *tp;
 453       ut_argument_spec
 454   {
 455     struct tm tmcopy;
 456     tmcopy = *tp;
 457     return _strftime_copytm (s, maxsize, format, &tmcopy ut_argument);
 458   }
 459 # undef my_strftime
 460 # define my_strftime(S, Maxsize, Format, Tp) \
 461   _strftime_copytm (S, Maxsize, Format, Tp)
 462 #endif
 463
 464
 465 /* Write information from TP into S according to the format
 466    string FORMAT, writing no more that MAXSIZE characters
 467    (including the terminating '\0') and returning number of
 468    characters written.  If S is NULL, nothing will be written
 469    anywhere, so to determine how many characters would be
 470    written, use NULL for S and (size_t) UINT_MAX for MAXSIZE.  */
 471 size_t
 472 my_strftime (s, maxsize, format, tp ut_argument)
 473       CHAR_T *s;
 474       size_t maxsize;
 475       const CHAR_T *format;
 476       const struct tm *tp;
 477       ut_argument_spec
 478 {
 479   int hour12 = tp->tm_hour;
 480 #ifdef _NL_CURRENT
 481   /* We cannot make the following values variables since we must delay
 482      the evaluation of these values until really needed since some
 483      expressions might not be valid in every situation.  The `struct tm'
 484      might be generated by a strptime() call that initialized
 485      only a few elements.  Dereference the pointers only if the format
 486      requires this.  Then it is ok to fail if the pointers are invalid.  */
 487 # define a_wkday \
 488   ((const CHAR_T *) _NL_CURRENT (LC_TIME, NLW(ABDAY_1) + tp->tm_wday))
 489 # define f_wkday \
 490   ((const CHAR_T *) _NL_CURRENT (LC_TIME, NLW(DAY_1) + tp->tm_wday))
 491 # define a_month \
 492   ((const CHAR_T *) _NL_CURRENT (LC_TIME, NLW(ABMON_1) + tp->tm_mon))
 493 # define f_month \
 494   ((const CHAR_T *) _NL_CURRENT (LC_TIME, NLW(MON_1) + tp->tm_mon))
 495 # define ampm \
 496   ((const CHAR_T *) _NL_CURRENT (LC_TIME, tp->tm_hour > 11                    \
 497                                  ? NLW(PM_STR) : NLW(AM_STR)))
 498
 499 # define aw_len STRLEN (a_wkday)
 500 # define am_len STRLEN (a_month)
 501 # define ap_len STRLEN (ampm)
 502 #else
 503 # if !HAVE_STRFTIME
 504 #  define f_wkday (weekday_name[tp->tm_wday])
 505 #  define f_month (month_name[tp->tm_mon])
 506 #  define a_wkday f_wkday
 507 #  define a_month f_month
 508 #  define ampm (L_("AMPM") + 2 * (tp->tm_hour > 11))
 509
 510   size_t aw_len = 3;
 511   size_t am_len = 3;
 512   size_t ap_len = 2;
 513 # endif
 514 #endif
 515   const char *zone;
 516   size_t i = 0;
 517   CHAR_T *p = s;
 518   const CHAR_T *f;
 519
 520   zone = NULL;
 521 #if HAVE_TM_ZONE
 522   /* The POSIX test suite assumes that setting
 523      the environment variable TZ to a new value before calling strftime()
 524      will influence the result (the %Z format) even if the information in
 525      TP is computed with a totally different time zone.
 526      This is bogus: though POSIX allows bad behavior like this,
 527      POSIX does not require it.  Do the right thing instead.  */
 528   zone = (const char *) tp->tm_zone;
 529 #endif
 530 #if HAVE_TZNAME
 531   if (ut)
 532     {
 533       if (! (zone && *zone))
 534         zone = "GMT";
 535     }
 536   else
 537     {
 538       /* POSIX.1 8.1.1 requires that whenever strftime() is called, the
 539          time zone names contained in the external variable `tzname' shall
 540          be set as if the tzset() function had been called.  */
 541 # if HAVE_TZSET
 542       tzset ();
 543 # endif
 544     }
 545 #endif
 546
 547   if (hour12 > 12)
 548     hour12 -= 12;
 549   else
 550     if (hour12 == 0)
 551       hour12 = 12;
 552
 553   for (f = format; *f != '\0'; ++f)
 554     {
 555       int pad = 0;              /* Padding for number ('-', '_', or 0).  */
 556       int modifier;             /* Field modifier ('E', 'O', or 0).  */
 557       int digits;               /* Max digits for numeric format.  */
 558       int number_value;         /* Numeric value to be printed.  */
 559       int negative_number;      /* 1 if the number is negative.  */
 560       const CHAR_T *subfmt;
 561       CHAR_T *bufp;
 562       CHAR_T buf[1 + (sizeof (int) < sizeof (time_t)
 563                       ? INT_STRLEN_BOUND (time_t)
 564                       : INT_STRLEN_BOUND (int))];
 565       int width = -1;
 566       int to_lowcase = 0;
 567       int to_uppcase = 0;
 568       int change_case = 0;
 569       int format_char;
 570
 571 #if DO_MULTIBYTE && !defined COMPILE_WIDE
 572       switch (*f)
 573         {
 574         case L_('%'):
 575           break;
 576
 577         case L_('\b'): case L_('\t'): case L_('\n'):
 578         case L_('\v'): case L_('\f'): case L_('\r'):
 579         case L_(' '): case L_('!'): case L_('"'): case L_('#'): case L_('&'):
 580         case L_('\''): case L_('('): case L_(')'): case L_('*'): case L_('+'):
 581         case L_(','): case L_('-'): case L_('.'): case L_('/'): case L_('0'):
 582         case L_('1'): case L_('2'): case L_('3'): case L_('4'): case L_('5'):
 583         case L_('6'): case L_('7'): case L_('8'): case L_('9'): case L_(':'):
 584         case L_(';'): case L_('<'): case L_('='): case L_('>'): case L_('?'):
 585         case L_('A'): case L_('B'): case L_('C'): case L_('D'): case L_('E'):
 586         case L_('F'): case L_('G'): case L_('H'): case L_('I'): case L_('J'):
 587         case L_('K'): case L_('L'): case L_('M'): case L_('N'): case L_('O'):
 588         case L_('P'): case L_('Q'): case L_('R'): case L_('S'): case L_('T'):
 589         case L_('U'): case L_('V'): case L_('W'): case L_('X'): case L_('Y'):
 590         case L_('Z'): case L_('['): case L_('\\'): case L_(']'): case L_('^'):
 591         case L_('_'): case L_('a'): case L_('b'): case L_('c'): case L_('d'):
 592         case L_('e'): case L_('f'): case L_('g'): case L_('h'): case L_('i'):
 593         case L_('j'): case L_('k'): case L_('l'): case L_('m'): case L_('n'):
 594         case L_('o'): case L_('p'): case L_('q'): case L_('r'): case L_('s'):
 595         case L_('t'): case L_('u'): case L_('v'): case L_('w'): case L_('x'):
 596         case L_('y'): case L_('z'): case L_('{'): case L_('|'): case L_('}'):
 597         case L_('~'):
 598           /* The C Standard requires these 98 characters (plus '%') to
 599              be in the basic execution character set.  None of these
 600              characters can start a multibyte sequence, so they need
 601              not be analyzed further.  */
 602           add (1, *p = *f);
 603           continue;
 604
 605         default:
 606           /* Copy this multibyte sequence until we reach its end, find
 607              an error, or come back to the initial shift state.  */
 608           {
 609             mbstate_t mbstate = mbstate_zero;
 610             size_t len = 0;
 611
 612             do
 613               {
 614                 size_t bytes = mbrlen (f + len, (size_t) -1, &mbstate);
 615
 616                 if (bytes == 0)
 617                   break;
 618
 619                 if (bytes == (size_t) -2)
 620                   {
 621                     len += strlen (f + len);
 622                     break;
 623                   }
 624
 625                 if (bytes == (size_t) -1)
 626                   {
 627                     len++;
 628                     break;
 629                   }
 630
 631                 len += bytes;
 632               }
 633             while (! mbsinit (&mbstate));
 634
 635             cpy (len, f);
 636             f += len - 1;
 637             continue;
 638           }
 639         }
 640
 641 #else /* ! DO_MULTIBYTE */
 642
 643       /* Either multibyte encodings are not supported, they are
 644          safe for formats, so any non-'%' byte can be copied through,
 645          or this is the wide character version.  */
 646       if (*f != L_('%'))
 647         {
 648           add (1, *p = *f);
 649           continue;
 650         }
 651
 652 #endif /* ! DO_MULTIBYTE */
 653
 654       /* Check for flags that can modify a format.  */
 655       while (1)
 656         {
 657           switch (*++f)
 658             {
 659               /* This influences the number formats.  */
 660             case L_('_'):
 661             case L_('-'):
 662             case L_('0'):
 663               pad = *f;
 664               continue;
 665
 666               /* This changes textual output.  */
 667             case L_('^'):
 668               to_uppcase = 1;
 669               continue;
 670             case L_('#'):
 671               change_case = 1;
 672               continue;
 673
 674             default:
 675               break;
 676             }
 677           break;
 678         }
 679
 680       /* As a GNU extension we allow to specify the field width.  */
 681       if (ISDIGIT (*f))
 682         {
 683           width = 0;
 684           do
 685             {
 686               width *= 10;
 687               width += *f - L_('0');
 688               ++f;
 689             }
 690           while (ISDIGIT (*f));
 691         }
 692
 693       /* Check for modifiers.  */
 694       switch (*f)
 695         {
 696         case L_('E'):
 697         case L_('O'):
 698           modifier = *f++;
 699           break;
 700
 701         default:
 702           modifier = 0;
 703           break;
 704         }
 705
 706       /* Now do the specified format.  */
 707       format_char = *f;
 708       switch (format_char)
 709         {
 710 #define DO_NUMBER(d, v) \
 711           digits = width == -1 ? d : width;                                   \
 712           number_value = v; goto do_number
 713 #define DO_NUMBER_SPACEPAD(d, v) \
 714           digits = width == -1 ? d : width;                                   \
 715           number_value = v; goto do_number_spacepad
 716
 717         case L_('%'):
 718           if (modifier != 0)
 719             goto bad_format;
 720           add (1, *p = *f);
 721           break;
 722
 723         case L_('a'):
 724           if (modifier != 0)
 725             goto bad_format;
 726           if (change_case)
 727             {
 728               to_uppcase = 1;
 729               to_lowcase = 0;
 730             }
 731 #if defined _NL_CURRENT || !HAVE_STRFTIME
 732           cpy (aw_len, a_wkday);
 733           break;
 734 #else
 735           goto underlying_strftime;
 736 #endif
 737
 738         case 'A':
 739           if (modifier != 0)
 740             goto bad_format;
 741           if (change_case)
 742             {
 743               to_uppcase = 1;
 744               to_lowcase = 0;
 745             }
 746 #if defined _NL_CURRENT || !HAVE_STRFTIME
 747           cpy (STRLEN (f_wkday), f_wkday);
 748           break;
 749 #else
 750           goto underlying_strftime;
 751 #endif
 752
 753         case L_('b'):
 754         case L_('h'):           /* POSIX.2 extension.  */
 755           if (modifier != 0)
 756             goto bad_format;
 757 #if defined _NL_CURRENT || !HAVE_STRFTIME
 758           cpy (am_len, a_month);
 759           break;
 760 #else
 761           goto underlying_strftime;
 762 #endif
 763
 764         case L_('B'):
 765           if (modifier != 0)
 766             goto bad_format;
 767           if (change_case)
 768             {
 769               to_uppcase = 1;
 770               to_lowcase = 0;
 771             }
 772 #if defined _NL_CURRENT || !HAVE_STRFTIME
 773           cpy (STRLEN (f_month), f_month);
 774           break;
 775 #else
 776           goto underlying_strftime;
 777 #endif
 778
 779         case L_('c'):
 780           if (modifier == L_('O'))
 781             goto bad_format;
 782 #ifdef _NL_CURRENT
 783           if (! (modifier == 'E'
 784                  && (*(subfmt = (CHAR_T *) _NL_CURRENT (LC_TIME,
 785                                                         NLW(ERA_D_T_FMT)))
 786                      != '\0')))
 787             subfmt = (CHAR_T *) _NL_CURRENT (LC_TIME, NLW(D_T_FMT));
 788 #else
 789 # if HAVE_STRFTIME
 790           goto underlying_strftime;
 791 # else
 792           subfmt = L_("%a %b %e %H:%M:%S %Y");
 793 # endif
 794 #endif
 795
 796         subformat:
 797           {
 798             CHAR_T *old_start = p;
 799             size_t len = my_strftime (NULL, (size_t) -1, subfmt, tp);
 800             add (len, my_strftime (p, maxsize - i, subfmt, tp));
 801
 802             if (to_uppcase)
 803               while (old_start < p)
 804                 {
 805                   *old_start = TOUPPER ((UCHAR_T) *old_start);
 806                   ++old_start;
 807                 }
 808           }
 809           break;
 810
 811 #if HAVE_STRFTIME && ! (defined _NL_CURRENT && HAVE_STRUCT_ERA_ENTRY)
 812         underlying_strftime:
 813           {
 814             /* The relevant information is available only via the
 815                underlying strftime implementation, so use that.  */
 816             char ufmt[4];
 817             char *u = ufmt;
 818             char ubuf[1024]; /* enough for any single format in practice */
 819             size_t len;
 820             /* Make sure we're calling the actual underlying strftime.
 821                In some cases, config.h contains something like
 822                "#define strftime rpl_strftime".  */
 823 # ifdef strftime
 824 #  undef strftime
 825 # endif
 826
 827             *u++ = '%';
 828             if (modifier != 0)
 829               *u++ = modifier;
 830             *u++ = format_char;
 831             *u = '\0';
 832             len = strftime (ubuf, sizeof ubuf, ufmt, tp);
 833             if (len == 0 && ubuf[0] != '\0')
 834               return 0;
 835             cpy (len, ubuf);
 836           }
 837           break;
 838 #endif
 839
 840         case L_('C'):           /* POSIX.2 extension.  */
 841           if (modifier == L_('O'))
 842             goto bad_format;
 843           if (modifier == L_('E'))
 844             {
 845 #if HAVE_STRUCT_ERA_ENTRY
 846               struct era_entry *era = _nl_get_era_entry (tp);
 847               if (era)
 848                 {
 849 # ifdef COMPILE_WIDE
 850                   size_t len = wcslen (era->era_wname);
 851                   cpy (len, era->era_wname);
 852 # else
 853                   size_t len = strlen (era->era_name);
 854                   cpy (len, era->era_name);
 855 # endif
 856                   break;
 857                 }
 858 #else
 859 # if HAVE_STRFTIME
 860               goto underlying_strftime;
 861 # endif
 862 #endif
 863             }
 864
 865           {
 866             int year = tp->tm_year + TM_YEAR_BASE;
 867             DO_NUMBER (1, year / 100 - (year % 100 < 0));
 868           }
 869
 870         case L_('x'):
 871           if (modifier == L_('O'))
 872             goto bad_format;
 873 #ifdef _NL_CURRENT
 874           if (! (modifier == L_('E')
 875                  && (*(subfmt = (CHAR_T *)_NL_CURRENT (LC_TIME,
 876                                                        NLW(ERA_D_FMT)))
 877                      != L_('\0'))))
 878             subfmt = (CHAR_T *) _NL_CURRENT (LC_TIME, NLW(D_FMT));
 879           goto subformat;
 880 #else
 881 # if HAVE_STRFTIME
 882           goto underlying_strftime;
 883 # else
 884           /* Fall through.  */
 885 # endif
 886 #endif
 887         case L_('D'):           /* POSIX.2 extension.  */
 888           if (modifier != 0)
 889             goto bad_format;
 890           subfmt = L_("%m/%d/%y");
 891           goto subformat;
 892
 893         case L_('d'):
 894           if (modifier == L_('E'))
 895             goto bad_format;
 896
 897           DO_NUMBER (2, tp->tm_mday);
 898
 899         case L_('e'):           /* POSIX.2 extension.  */
 900           if (modifier == L_('E'))
 901             goto bad_format;
 902
 903           DO_NUMBER_SPACEPAD (2, tp->tm_mday);
 904
 905           /* All numeric formats set DIGITS and NUMBER_VALUE and then
 906              jump to one of these two labels.  */
 907
 908         do_number_spacepad:
 909           /* Force `_' flag unless overwritten by `0' flag.  */
 910           if (pad != L_('0'))
 911             pad = L_('_');
 912
 913         do_number:
 914           /* Format the number according to the MODIFIER flag.  */
 915
 916           if (modifier == L_('O') && 0 <= number_value)
 917             {
 918 #ifdef _NL_CURRENT
 919               /* Get the locale specific alternate representation of
 920                  the number NUMBER_VALUE.  If none exist NULL is returned.  */
 921 # ifdef COMPILE_WIDE
 922               const wchar_t *cp = _nl_get_walt_digit (number_value);
 923 # else
 924               const char *cp = _nl_get_alt_digit (number_value);
 925 # endif
 926
 927               if (cp != NULL)
 928                 {
 929                   size_t digitlen = STRLEN (cp);
 930                   if (digitlen != 0)
 931                     {
 932                       cpy (digitlen, cp);
 933                       break;
 934                     }
 935                 }
 936 #else
 937 # if HAVE_STRFTIME
 938               goto underlying_strftime;
 939 # endif
 940 #endif
 941             }
 942           {
 943             unsigned int u = number_value;
 944
 945             bufp = buf + sizeof (buf) / sizeof (buf[0]);
 946             negative_number = number_value < 0;
 947
 948             if (negative_number)
 949               u = -u;
 950
 951             do
 952               *--bufp = u % 10 + L_('0');
 953             while ((u /= 10) != 0);
 954           }
 955
 956         do_number_sign_and_padding:
 957           if (negative_number)
 958             *--bufp = L_('-');
 959
 960           if (pad != L_('-'))
 961             {
 962               int padding = digits - (buf + (sizeof (buf) / sizeof (buf[0]))
 963                                       - bufp);
 964
 965               if (pad == L_('_'))
 966                 {
 967                   while (0 < padding--)
 968                     *--bufp = L_(' ');
 969                 }
 970               else
 971                 {
 972                   bufp += negative_number;
 973                   while (0 < padding--)
 974                     *--bufp = L_('0');
 975                   if (negative_number)
 976                     *--bufp = L_('-');
 977                 }
 978             }
 979
 980           cpy (buf + sizeof (buf) / sizeof (buf[0]) - bufp, bufp);
 981           break;
 982
 983         case L_('F'):
 984           if (modifier != 0)
 985             goto bad_format;
 986           subfmt = L_("%Y-%m-%d");
 987           goto subformat;
 988
 989         case L_('H'):
 990           if (modifier == L_('E'))
 991             goto bad_format;
 992
 993           DO_NUMBER (2, tp->tm_hour);
 994
 995         case L_('I'):
 996           if (modifier == L_('E'))
 997             goto bad_format;
 998
 999           DO_NUMBER (2, hour12);
1000
1001         case L_('k'):           /* GNU extension.  */
1002           if (modifier == L_('E'))
1003             goto bad_format;
1004
1005           DO_NUMBER_SPACEPAD (2, tp->tm_hour);
1006
1007         case L_('l'):           /* GNU extension.  */
1008           if (modifier == L_('E'))
1009             goto bad_format;
1010
1011           DO_NUMBER_SPACEPAD (2, hour12);
1012
1013         case L_('j'):
1014           if (modifier == L_('E'))
1015             goto bad_format;
1016
1017           DO_NUMBER (3, 1 + tp->tm_yday);
1018
1019         case L_('M'):
1020           if (modifier == L_('E'))
1021             goto bad_format;
1022
1023           DO_NUMBER (2, tp->tm_min);
1024
1025         case L_('m'):
1026           if (modifier == L_('E'))
1027             goto bad_format;
1028
1029           DO_NUMBER (2, tp->tm_mon + 1);
1030
1031         case L_('n'):           /* POSIX.2 extension.  */
1032           add (1, *p = L_('\n'));
1033           break;
1034
1035         case L_('P'):
1036           to_lowcase = 1;
1037 #if !defined _NL_CURRENT && HAVE_STRFTIME
1038           format_char = L_('p');
1039 #endif
1040           /* FALLTHROUGH */
1041
1042         case L_('p'):
1043           if (change_case)
1044             {
1045               to_uppcase = 0;
1046               to_lowcase = 1;
1047             }
1048 #if defined _NL_CURRENT || !HAVE_STRFTIME
1049           cpy (ap_len, ampm);
1050           break;
1051 #else
1052           goto underlying_strftime;
1053 #endif
1054
1055         case L_('R'):           /* GNU extension.  */
1056           subfmt = L_("%H:%M");
1057           goto subformat;
1058
1059         case L_('r'):           /* POSIX.2 extension.  */
1060 #ifdef _NL_CURRENT
1061           if (*(subfmt = (CHAR_T *) _NL_CURRENT (LC_TIME,
1062                                                  NLW(T_FMT_AMPM))) == L_('\0'))
1063 #endif
1064             subfmt = L_("%I:%M:%S %p");
1065           goto subformat;
1066
1067         case L_('S'):
1068           if (modifier == L_('E'))
1069             goto bad_format;
1070
1071           DO_NUMBER (2, tp->tm_sec);
1072
1073         case L_('s'):           /* GNU extension.  */
1074           {
1075             struct tm ltm;
1076             time_t t;
1077
1078             ltm = *tp;
1079             t = mktime (&ltm);
1080
1081             /* Generate string value for T using time_t arithmetic;
1082                this works even if sizeof (long) < sizeof (time_t).  */
1083
1084             bufp = buf + sizeof (buf) / sizeof (buf[0]);
1085             negative_number = t < 0;
1086
1087             do
1088               {
1089                 int d = t % 10;
1090                 t /= 10;
1091
1092                 if (negative_number)
1093                   {
1094                     d = -d;
1095
1096                     /* Adjust if division truncates to minus infinity.  */
1097                     if (0 < -1 % 10 && d < 0)
1098                       {
1099                         t++;
1100                         d += 10;
1101                       }
1102                   }
1103
1104                 *--bufp = d + L_('0');
1105               }
1106             while (t != 0);
1107
1108             digits = 1;
1109             goto do_number_sign_and_padding;
1110           }
1111
1112         case L_('X'):
1113           if (modifier == L_('O'))
1114             goto bad_format;
1115 #ifdef _NL_CURRENT
1116           if (! (modifier == L_('E')
1117                  && (*(subfmt = (CHAR_T *) _NL_CURRENT (LC_TIME,
1118                                                         NLW(ERA_T_FMT)))
1119                      != L_('\0'))))
1120             subfmt = (CHAR_T *) _NL_CURRENT (LC_TIME, NLW(T_FMT));
1121           goto subformat;
1122 #else
1123 # if HAVE_STRFTIME
1124           goto underlying_strftime;
1125 # else
1126           /* Fall through.  */
1127 # endif
1128 #endif
1129         case L_('T'):           /* POSIX.2 extension.  */
1130           subfmt = L_("%H:%M:%S");
1131           goto subformat;
1132
1133         case L_('t'):           /* POSIX.2 extension.  */
1134           add (1, *p = L_('\t'));
1135           break;
1136
1137         case L_('u'):           /* POSIX.2 extension.  */
1138           DO_NUMBER (1, (tp->tm_wday - 1 + 7) % 7 + 1);
1139
1140         case L_('U'):
1141           if (modifier == L_('E'))
1142             goto bad_format;
1143
1144           DO_NUMBER (2, (tp->tm_yday - tp->tm_wday + 7) / 7);
1145
1146         case L_('V'):
1147         case L_('g'):           /* GNU extension.  */
1148         case L_('G'):           /* GNU extension.  */
1149           if (modifier == L_('E'))
1150             goto bad_format;
1151           {
1152             int year = tp->tm_year + TM_YEAR_BASE;
1153             int days = iso_week_days (tp->tm_yday, tp->tm_wday);
1154
1155             if (days < 0)
1156               {
1157                 /* This ISO week belongs to the previous year.  */
1158                 year--;
1159                 days = iso_week_days (tp->tm_yday + (365 + __isleap (year)),
1160                                       tp->tm_wday);
1161               }
1162             else
1163               {
1164                 int d = iso_week_days (tp->tm_yday - (365 + __isleap (year)),
1165                                        tp->tm_wday);
1166                 if (0 <= d)
1167                   {
1168                     /* This ISO week belongs to the next year.  */
1169                     year++;
1170                     days = d;
1171                   }
1172               }
1173
1174             switch (*f)
1175               {
1176               case L_('g'):
1177                 DO_NUMBER (2, (year % 100 + 100) % 100);
1178
1179               case L_('G'):
1180                 DO_NUMBER (1, year);
1181
1182               default:
1183                 DO_NUMBER (2, days / 7 + 1);
1184               }
1185           }
1186
1187         case L_('W'):
1188           if (modifier == L_('E'))
1189             goto bad_format;
1190
1191           DO_NUMBER (2, (tp->tm_yday - (tp->tm_wday - 1 + 7) % 7 + 7) / 7);
1192
1193         case L_('w'):
1194           if (modifier == L_('E'))
1195             goto bad_format;
1196
1197           DO_NUMBER (1, tp->tm_wday);
1198
1199         case L_('Y'):
1200           if (modifier == 'E')
1201             {
1202 #if HAVE_STRUCT_ERA_ENTRY
1203               struct era_entry *era = _nl_get_era_entry (tp);
1204               if (era)
1205                 {
1206 # ifdef COMPILE_WIDE
1207                   subfmt = era->era_wformat;
1208 # else
1209                   subfmt = era->era_format;
1210 # endif
1211                   goto subformat;
1212                 }
1213 #else
1214 # if HAVE_STRFTIME
1215               goto underlying_strftime;
1216 # endif
1217 #endif
1218             }
1219           if (modifier == L_('O'))
1220             goto bad_format;
1221           else
1222             DO_NUMBER (1, tp->tm_year + TM_YEAR_BASE);
1223
1224         case L_('y'):
1225           if (modifier == L_('E'))
1226             {
1227 #if HAVE_STRUCT_ERA_ENTRY
1228               struct era_entry *era = _nl_get_era_entry (tp);
1229               if (era)
1230                 {
1231                   int delta = tp->tm_year - era->start_date[0];
1232                   DO_NUMBER (1, (era->offset
1233                                  + delta * era->absolute_direction));
1234                 }
1235 #else
1236 # if HAVE_STRFTIME
1237               goto underlying_strftime;
1238 # endif
1239 #endif
1240             }
1241           DO_NUMBER (2, (tp->tm_year % 100 + 100) % 100);
1242
1243         case L_('Z'):
1244           if (change_case)
1245             {
1246               to_uppcase = 0;
1247               to_lowcase = 1;
1248             }
1249
1250 #if HAVE_TZNAME
1251           /* The tzset() call might have changed the value.  */
1252           if (!(zone && *zone) && tp->tm_isdst >= 0)
1253             zone = tzname[tp->tm_isdst];
1254 #endif
1255           if (! zone)
1256             zone = "";          /* POSIX.2 requires the empty string here.  */
1257
1258 #ifdef COMPILE_WIDE
1259           {
1260             /* The zone string is always given in multibyte form.  We have
1261                to transform it first.  */
1262             wchar_t *wczone;
1263             size_t len;
1264             widen (zone, wczone, len);
1265             cpy (len, wczone);
1266           }
1267 #else
1268           cpy (strlen (zone), zone);
1269 #endif
1270           break;
1271
1272         case L_('z'):           /* GNU extension.  */
1273           if (tp->tm_isdst < 0)
1274             break;
1275
1276           {
1277             int diff;
1278 #if HAVE_TM_GMTOFF
1279             diff = tp->tm_gmtoff;
1280 #else
1281             if (ut)
1282               diff = 0;
1283             else
1284               {
1285                 struct tm gtm;
1286                 struct tm ltm;
1287                 time_t lt;
1288
1289                 ltm = *tp;
1290                 lt = mktime (&ltm);
1291
1292                 if (lt == (time_t) -1)
1293                   {
1294                     /* mktime returns -1 for errors, but -1 is also a
1295                        valid time_t value.  Check whether an error really
1296                        occurred.  */
1297                     struct tm tm;
1298
1299                     if (! my_strftime_localtime_r (&lt, &tm)
1300                         || ((ltm.tm_sec ^ tm.tm_sec)
1301                             | (ltm.tm_min ^ tm.tm_min)
1302                             | (ltm.tm_hour ^ tm.tm_hour)
1303                             | (ltm.tm_mday ^ tm.tm_mday)
1304                             | (ltm.tm_mon ^ tm.tm_mon)
1305                             | (ltm.tm_year ^ tm.tm_year)))
1306                       break;
1307                   }
1308
1309                 if (! my_strftime_gmtime_r (&lt, &gtm))
1310                   break;
1311
1312                 diff = tm_diff (&ltm, &gtm);
1313               }
1314 #endif
1315
1316             if (diff < 0)
1317               {
1318                 add (1, *p = L_('-'));
1319                 diff = -diff;
1320               }
1321             else
1322               add (1, *p = L_('+'));
1323
1324             diff /= 60;
1325             DO_NUMBER (4, (diff / 60) * 100 + diff % 60);
1326           }
1327
1328         case L_('\0'):          /* GNU extension: % at end of format.  */
1329             --f;
1330             /* Fall through.  */
1331         default:
1332           /* Unknown format; output the format, including the '%',
1333              since this is most likely the right thing to do if a
1334              multibyte string has been misparsed.  */
1335         bad_format:
1336           {
1337             int flen;
1338             for (flen = 1; f[1 - flen] != L_('%'); flen++)
1339               continue;
1340             cpy (flen, &f[1 - flen]);
1341           }
1342           break;
1343         }
1344     }
1345
1346   if (p && maxsize != 0)
1347     *p = L_('\0');
1348   return i;
1349 }
1350
1351
1352 #ifdef emacs
1353 /* For Emacs we have a separate interface which corresponds to the normal
1354    strftime function and does not have the extra information whether the
1355    TP arguments comes from a `gmtime' call or not.  */
1356 size_t
1357 emacs_strftime (s, maxsize, format, tp)
1358       char *s;
1359       size_t maxsize;
1360       const char *format;
1361       const struct tm *tp;
1362 {
1363   return my_strftime (s, maxsize, format, tp, 0);
1364 }
1365 #endif