Ruby  2.0.0p247(2013-06-27revision41674)
strftime.c
Go to the documentation of this file.
00001 /* -*- c-file-style: "linux" -*- */
00002 
00003 /*
00004  * strftime.c
00005  *
00006  * Public-domain implementation of ANSI C library routine.
00007  *
00008  * It's written in old-style C for maximal portability.
00009  * However, since I'm used to prototypes, I've included them too.
00010  *
00011  * If you want stuff in the System V ascftime routine, add the SYSV_EXT define.
00012  * For extensions from SunOS, add SUNOS_EXT.
00013  * For stuff needed to implement the P1003.2 date command, add POSIX2_DATE.
00014  * For VMS dates, add VMS_EXT.
00015  * For a an RFC822 time format, add MAILHEADER_EXT.
00016  * For ISO week years, add ISO_DATE_EXT.
00017  * For complete POSIX semantics, add POSIX_SEMANTICS.
00018  *
00019  * The code for %c, %x, and %X now follows the 1003.2 specification for
00020  * the POSIX locale.
00021  * This version ignores LOCALE information.
00022  * It also doesn't worry about multi-byte characters.
00023  * So there.
00024  *
00025  * This file is also shipped with GAWK (GNU Awk), gawk specific bits of
00026  * code are included if GAWK is defined.
00027  *
00028  * Arnold Robbins
00029  * January, February, March, 1991
00030  * Updated March, April 1992
00031  * Updated April, 1993
00032  * Updated February, 1994
00033  * Updated May, 1994
00034  * Updated January, 1995
00035  * Updated September, 1995
00036  * Updated January, 1996
00037  *
00038  * Fixes from ado@elsie.nci.nih.gov
00039  * February 1991, May 1992
00040  * Fixes from Tor Lillqvist tml@tik.vtt.fi
00041  * May, 1993
00042  * Further fixes from ado@elsie.nci.nih.gov
00043  * February 1994
00044  * %z code from chip@chinacat.unicom.com
00045  * Applied September 1995
00046  * %V code fixed (again) and %G, %g added,
00047  * January 1996
00048  */
00049 
00050 #include "ruby/ruby.h"
00051 #include "ruby/encoding.h"
00052 #include "timev.h"
00053 
00054 #ifndef GAWK
00055 #include <stdio.h>
00056 #include <ctype.h>
00057 #include <string.h>
00058 #include <time.h>
00059 #include <sys/types.h>
00060 #include <errno.h>
00061 #endif
00062 #if defined(TM_IN_SYS_TIME) || !defined(GAWK)
00063 #include <sys/types.h>
00064 #if HAVE_SYS_TIME_H
00065 #include <sys/time.h>
00066 #endif
00067 #endif
00068 #include <math.h>
00069 
00070 /* defaults: season to taste */
00071 #define SYSV_EXT        1       /* stuff in System V ascftime routine */
00072 #define SUNOS_EXT       1       /* stuff in SunOS strftime routine */
00073 #define POSIX2_DATE     1       /* stuff in Posix 1003.2 date command */
00074 #define VMS_EXT         1       /* include %v for VMS date format */
00075 #define MAILHEADER_EXT  1       /* add %z for HHMM format */
00076 #define ISO_DATE_EXT    1       /* %G and %g for year of ISO week */
00077 
00078 #if defined(ISO_DATE_EXT)
00079 #if ! defined(POSIX2_DATE)
00080 #define POSIX2_DATE     1
00081 #endif
00082 #endif
00083 
00084 #if defined(POSIX2_DATE)
00085 #if ! defined(SYSV_EXT)
00086 #define SYSV_EXT        1
00087 #endif
00088 #if ! defined(SUNOS_EXT)
00089 #define SUNOS_EXT       1
00090 #endif
00091 #endif
00092 
00093 #if defined(POSIX2_DATE)
00094 #define adddecl(stuff)  stuff
00095 #else
00096 #define adddecl(stuff)
00097 #endif
00098 
00099 #undef strchr   /* avoid AIX weirdness */
00100 
00101 #if !defined __STDC__ && !defined _WIN32
00102 #define const   
00103 static int weeknumber();
00104 adddecl(static int iso8601wknum();)
00105 static int weeknumber_v();
00106 adddecl(static int iso8601wknum_v();)
00107 #else
00108 static int weeknumber(const struct tm *timeptr, int firstweekday);
00109 adddecl(static int iso8601wknum(const struct tm *timeptr);)
00110 static int weeknumber_v(const struct vtm *vtm, int firstweekday);
00111 adddecl(static int iso8601wknum_v(const struct vtm *vtm);)
00112 #endif
00113 
00114 #ifdef STDC_HEADERS
00115 #include <stdlib.h>
00116 #include <string.h>
00117 #else
00118 extern void *malloc();
00119 extern void *realloc();
00120 extern char *getenv();
00121 extern char *strchr();
00122 #endif
00123 
00124 #define range(low, item, hi)    max((low), min((item), (hi)))
00125 
00126 #undef min      /* just in case */
00127 
00128 /* min --- return minimum of two numbers */
00129 
00130 static inline int
00131 min(int a, int b)
00132 {
00133         return (a < b ? a : b);
00134 }
00135 
00136 #undef max      /* also, just in case */
00137 
00138 /* max --- return maximum of two numbers */
00139 
00140 static inline int
00141 max(int a, int b)
00142 {
00143         return (a > b ? a : b);
00144 }
00145 
00146 #ifdef NO_STRING_LITERAL_CONCATENATION
00147 #error No string literal concatenation
00148 #endif
00149 
00150 #define add(x,y) (rb_funcall((x), '+', 1, (y)))
00151 #define sub(x,y) (rb_funcall((x), '-', 1, (y)))
00152 #define mul(x,y) (rb_funcall((x), '*', 1, (y)))
00153 #define quo(x,y) (rb_funcall((x), rb_intern("quo"), 1, (y)))
00154 #define div(x,y) (rb_funcall((x), rb_intern("div"), 1, (y)))
00155 #define mod(x,y) (rb_funcall((x), '%', 1, (y)))
00156 
00157 /* strftime --- produce formatted time */
00158 
00159 /*
00160  * enc is the encoding of the format. It is used as the encoding of resulted
00161  * string, but the name of the month and weekday are always US-ASCII. So it
00162  * is only used for the timezone name on Windows.
00163  */
00164 static size_t
00165 rb_strftime_with_timespec(char *s, size_t maxsize, const char *format, rb_encoding *enc, const struct vtm *vtm, VALUE timev, struct timespec *ts, int gmt)
00166 {
00167         const char *const endp = s + maxsize;
00168         const char *const start = s;
00169         const char *sp, *tp;
00170 #define TBUFSIZE 100
00171         auto char tbuf[TBUFSIZE];
00172         long off;
00173         ptrdiff_t i;
00174         int w;
00175         long y;
00176         int precision, flags, colons;
00177         char padding;
00178         enum {LEFT, CHCASE, LOWER, UPPER};
00179 #define BIT_OF(n) (1U<<(n))
00180 #ifdef MAILHEADER_EXT
00181         int sign;
00182 #endif
00183 
00184         /* various tables, useful in North America */
00185         static const char days_l[][10] = {
00186                 "Sunday", "Monday", "Tuesday", "Wednesday",
00187                 "Thursday", "Friday", "Saturday",
00188         };
00189         static const char months_l[][10] = {
00190                 "January", "February", "March", "April",
00191                 "May", "June", "July", "August", "September",
00192                 "October", "November", "December",
00193         };
00194         static const char ampm[][3] = { "AM", "PM", };
00195 
00196         if (s == NULL || format == NULL || vtm == NULL || maxsize == 0)
00197                 return 0;
00198 
00199         /* quick check if we even need to bother */
00200         if (strchr(format, '%') == NULL && strlen(format) + 1 >= maxsize) {
00201         err:
00202                 errno = ERANGE;
00203                 return 0;
00204         }
00205 
00206         if (enc && (enc == rb_usascii_encoding() ||
00207             enc == rb_ascii8bit_encoding() || enc == rb_locale_encoding())) {
00208             enc = NULL;
00209         }
00210 
00211         for (; *format && s < endp - 1; format++) {
00212 #define FLAG_FOUND() do { \
00213                         if (precision > 0) \
00214                                 goto unknown; \
00215                 } while (0)
00216 #define NEEDS(n) do if (s >= endp || (n) >= endp - s - 1) goto err; while (0)
00217 #define FILL_PADDING(i) do { \
00218         if (!(flags & BIT_OF(LEFT)) && precision > (i)) { \
00219                 NEEDS(precision); \
00220                 memset(s, padding ? padding : ' ', precision - (i)); \
00221                 s += precision - (i); \
00222         } \
00223         else { \
00224                 NEEDS(i); \
00225         } \
00226 } while (0);
00227 #define FMT(def_pad, def_prec, fmt, val) \
00228                 do { \
00229                         int l; \
00230                         if (precision <= 0) precision = (def_prec); \
00231                         if (flags & BIT_OF(LEFT)) precision = 1; \
00232                         l = snprintf(s, endp - s, \
00233                                      ((padding == '0' || (!padding && (def_pad) == '0')) ? "%0*"fmt : "%*"fmt), \
00234                                      precision, (val)); \
00235                         if (l < 0) goto err; \
00236                         s += l; \
00237                 } while (0)
00238 #define STRFTIME(fmt) \
00239                 do { \
00240                         i = rb_strftime_with_timespec(s, endp - s, (fmt), enc, vtm, timev, ts, gmt); \
00241                         if (!i) return 0; \
00242                         if (precision > i) {\
00243                                 NEEDS(precision); \
00244                                 memmove(s + precision - i, s, i);\
00245                                 memset(s, padding ? padding : ' ', precision - i); \
00246                                 s += precision; \
00247                         }\
00248                         else s += i; \
00249                 } while (0)
00250 #define FMTV(def_pad, def_prec, fmt, val) \
00251                 do { \
00252                         VALUE tmp = (val); \
00253                         if (FIXNUM_P(tmp)) { \
00254                                 FMT((def_pad), (def_prec), "l"fmt, FIX2LONG(tmp)); \
00255                         } \
00256                         else { \
00257                                 VALUE args[2], result; \
00258                                 size_t l; \
00259                                 if (precision <= 0) precision = (def_prec); \
00260                                 if (flags & BIT_OF(LEFT)) precision = 1; \
00261                                 args[0] = INT2FIX(precision); \
00262                                 args[1] = (val); \
00263                                 if (padding == '0' || (!padding && (def_pad) == '0')) \
00264                                         result = rb_str_format(2, args, rb_str_new2("%0*"fmt)); \
00265                                 else \
00266                                         result = rb_str_format(2, args, rb_str_new2("%*"fmt)); \
00267                                 l = strlcpy(s, StringValueCStr(result), endp-s); \
00268                                 if ((size_t)(endp-s) <= l) \
00269                                         goto err; \
00270                                 s += l; \
00271                         } \
00272                 } while (0)
00273 
00274                 if (*format != '%') {
00275                         *s++ = *format;
00276                         continue;
00277                 }
00278                 tp = tbuf;
00279                 sp = format;
00280                 precision = -1;
00281                 flags = 0;
00282                 padding = 0;
00283                 colons = 0;
00284         again:
00285                 switch (*++format) {
00286                 case '\0':
00287                         format--;
00288                         goto unknown;
00289 
00290                 case '%':
00291                         FILL_PADDING(1);
00292                         *s++ = '%';
00293                         continue;
00294 
00295                 case 'a':       /* abbreviated weekday name */
00296                         if (flags & BIT_OF(CHCASE)) {
00297                                 flags &= ~(BIT_OF(LOWER)|BIT_OF(CHCASE));
00298                                 flags |= BIT_OF(UPPER);
00299                         }
00300                         if (vtm->wday < 0 || vtm->wday > 6)
00301                                 i = 1, tp = "?";
00302                         else
00303                                 i = 3, tp = days_l[vtm->wday];
00304                         break;
00305 
00306                 case 'A':       /* full weekday name */
00307                         if (flags & BIT_OF(CHCASE)) {
00308                                 flags &= ~(BIT_OF(LOWER)|BIT_OF(CHCASE));
00309                                 flags |= BIT_OF(UPPER);
00310                         }
00311                         if (vtm->wday < 0 || vtm->wday > 6)
00312                                 i = 1, tp = "?";
00313                         else
00314                                 i = strlen(tp = days_l[vtm->wday]);
00315                         break;
00316 
00317 #ifdef SYSV_EXT
00318                 case 'h':       /* abbreviated month name */
00319 #endif
00320                 case 'b':       /* abbreviated month name */
00321                         if (flags & BIT_OF(CHCASE)) {
00322                                 flags &= ~(BIT_OF(LOWER)|BIT_OF(CHCASE));
00323                                 flags |= BIT_OF(UPPER);
00324                         }
00325                         if (vtm->mon < 1 || vtm->mon > 12)
00326                                 i = 1, tp = "?";
00327                         else
00328                                 i = 3, tp = months_l[vtm->mon-1];
00329                         break;
00330 
00331                 case 'B':       /* full month name */
00332                         if (flags & BIT_OF(CHCASE)) {
00333                                 flags &= ~(BIT_OF(LOWER)|BIT_OF(CHCASE));
00334                                 flags |= BIT_OF(UPPER);
00335                         }
00336                         if (vtm->mon < 1 || vtm->mon > 12)
00337                                 i = 1, tp = "?";
00338                         else
00339                                 i = strlen(tp = months_l[vtm->mon-1]);
00340                         break;
00341 
00342                 case 'c':       /* appropriate date and time representation */
00343                         STRFTIME("%a %b %e %H:%M:%S %Y");
00344                         continue;
00345 
00346                 case 'd':       /* day of the month, 01 - 31 */
00347                         i = range(1, vtm->mday, 31);
00348                         FMT('0', 2, "d", (int)i);
00349                         continue;
00350 
00351                 case 'H':       /* hour, 24-hour clock, 00 - 23 */
00352                         i = range(0, vtm->hour, 23);
00353                         FMT('0', 2, "d", (int)i);
00354                         continue;
00355 
00356                 case 'I':       /* hour, 12-hour clock, 01 - 12 */
00357                         i = range(0, vtm->hour, 23);
00358                         if (i == 0)
00359                                 i = 12;
00360                         else if (i > 12)
00361                                 i -= 12;
00362                         FMT('0', 2, "d", (int)i);
00363                         continue;
00364 
00365                 case 'j':       /* day of the year, 001 - 366 */
00366                         FMT('0', 3, "d", vtm->yday);
00367                         continue;
00368 
00369                 case 'm':       /* month, 01 - 12 */
00370                         i = range(1, vtm->mon, 12);
00371                         FMT('0', 2, "d", (int)i);
00372                         continue;
00373 
00374                 case 'M':       /* minute, 00 - 59 */
00375                         i = range(0, vtm->min, 59);
00376                         FMT('0', 2, "d", (int)i);
00377                         continue;
00378 
00379                 case 'p':       /* AM or PM based on 12-hour clock */
00380                 case 'P':       /* am or pm based on 12-hour clock */
00381                         if ((*format == 'p' && (flags & BIT_OF(CHCASE))) ||
00382                             (*format == 'P' && !(flags & (BIT_OF(CHCASE)|BIT_OF(UPPER))))) {
00383                                 flags &= ~(BIT_OF(UPPER)|BIT_OF(CHCASE));
00384                                 flags |= BIT_OF(LOWER);
00385                         }
00386                         i = range(0, vtm->hour, 23);
00387                         if (i < 12)
00388                                 tp = ampm[0];
00389                         else
00390                                 tp = ampm[1];
00391                         i = 2;
00392                         break;
00393 
00394                 case 's':
00395                         if (ts) {
00396                                 time_t sec = ts->tv_sec;
00397                                 if (~(time_t)0 <= 0)
00398                                     FMT('0', 1, PRI_TIMET_PREFIX"d", sec);
00399                                 else
00400                                     FMT('0', 1, PRI_TIMET_PREFIX"u", sec);
00401                         }
00402                         else {
00403                                 VALUE sec = div(timev, INT2FIX(1));
00404                                 FMTV('0', 1, "d", sec);
00405                         }
00406                         continue;
00407 
00408                 case 'S':       /* second, 00 - 60 */
00409                         i = range(0, vtm->sec, 60);
00410                         FMT('0', 2, "d", (int)i);
00411                         continue;
00412 
00413                 case 'U':       /* week of year, Sunday is first day of week */
00414                         FMT('0', 2, "d", weeknumber_v(vtm, 0));
00415                         continue;
00416 
00417                 case 'w':       /* weekday, Sunday == 0, 0 - 6 */
00418                         i = range(0, vtm->wday, 6);
00419                         FMT('0', 1, "d", (int)i);
00420                         continue;
00421 
00422                 case 'W':       /* week of year, Monday is first day of week */
00423                         FMT('0', 2, "d", weeknumber_v(vtm, 1));
00424                         continue;
00425 
00426                 case 'x':       /* appropriate date representation */
00427                         STRFTIME("%m/%d/%y");
00428                         continue;
00429 
00430                 case 'X':       /* appropriate time representation */
00431                         STRFTIME("%H:%M:%S");
00432                         continue;
00433 
00434                 case 'y':       /* year without a century, 00 - 99 */
00435                         i = NUM2INT(mod(vtm->year, INT2FIX(100)));
00436                         FMT('0', 2, "d", (int)i);
00437                         continue;
00438 
00439                 case 'Y':       /* year with century */
00440                         if (FIXNUM_P(vtm->year)) {
00441                                 long y = FIX2LONG(vtm->year);
00442                                 FMT('0', 0 <= y ? 4 : 5, "ld", y);
00443                         }
00444                         else {
00445                                 FMTV('0', 4, "d", vtm->year);
00446                         }
00447                         continue;
00448 
00449 #ifdef MAILHEADER_EXT
00450                 case 'z':       /* time zone offset east of GMT e.g. -0600 */
00451                         if (gmt) {
00452                                 off = 0;
00453                         }
00454                         else {
00455                                 off = NUM2LONG(rb_funcall(vtm->utc_offset, rb_intern("round"), 0));
00456                         }
00457                         if (off < 0) {
00458                                 off = -off;
00459                                 sign = -1;
00460                         } else {
00461                                 sign = +1;
00462                         }
00463                         switch (colons) {
00464                         case 0: /* %z -> +hhmm */
00465                                 precision = precision <= 5 ? 2 : precision-3;
00466                                 NEEDS(precision + 3);
00467                                 break;
00468 
00469                         case 1: /* %:z -> +hh:mm */
00470                                 precision = precision <= 6 ? 2 : precision-4;
00471                                 NEEDS(precision + 4);
00472                                 break;
00473 
00474                         case 2: /* %::z -> +hh:mm:ss */
00475                                 precision = precision <= 9 ? 2 : precision-7;
00476                                 NEEDS(precision + 7);
00477                                 break;
00478 
00479                         case 3: /* %:::z -> +hh[:mm[:ss]] */
00480                                 if (off % 3600 == 0) {
00481                                         precision = precision <= 3 ? 2 : precision-1;
00482                                         NEEDS(precision + 3);
00483                                 }
00484                                 else if (off % 60 == 0) {
00485                                         precision = precision <= 6 ? 2 : precision-4;
00486                                         NEEDS(precision + 4);
00487                                 }
00488                                 else {
00489                                         precision = precision <= 9 ? 2 : precision-7;
00490                                         NEEDS(precision + 9);
00491                                 }
00492                                 break;
00493 
00494                         default:
00495                                 format--;
00496                                 goto unknown;
00497                         }
00498                         i = snprintf(s, endp - s, (padding == ' ' ? "%+*ld" : "%+.*ld"),
00499                                      precision + 1, sign * (off / 3600));
00500                         if (i < 0) goto err;
00501                         if (sign < 0 && off < 3600) {
00502                                 *(padding == ' ' ? s + i - 2 : s) = '-';
00503                         }
00504                         s += i;
00505                         off = off % 3600;
00506                         if (colons == 3 && off == 0)
00507                                 continue;
00508                         if (1 <= colons)
00509                             *s++ = ':';
00510                         i = snprintf(s, endp - s, "%02d", (int)(off / 60));
00511                         if (i < 0) goto err;
00512                         s += i;
00513                         off = off % 60;
00514                         if (colons == 3 && off == 0)
00515                                 continue;
00516                         if (2 <= colons) {
00517                             *s++ = ':';
00518                             i = snprintf(s, endp - s, "%02d", (int)off);
00519                             if (i < 0) goto err;
00520                             s += i;
00521                         }
00522                         continue;
00523 #endif /* MAILHEADER_EXT */
00524 
00525                 case 'Z':       /* time zone name or abbreviation */
00526                         if (flags & BIT_OF(CHCASE)) {
00527                                 flags &= ~(BIT_OF(UPPER)|BIT_OF(CHCASE));
00528                                 flags |= BIT_OF(LOWER);
00529                         }
00530                         if (gmt) {
00531                                 i = 3;
00532                                 tp = "UTC";
00533                                 break;
00534                         }
00535                         if (vtm->zone == NULL) {
00536                             i = 0;
00537                         }
00538                         else {
00539                             tp = vtm->zone;
00540                             if (enc) {
00541                                 for (i = 0; i < TBUFSIZE && tp[i]; i++) {
00542                                     if ((unsigned char)tp[i] > 0x7F) {
00543                                         VALUE str = rb_str_conv_enc_opts(rb_str_new_cstr(tp), rb_locale_encoding(), enc, ECONV_UNDEF_REPLACE|ECONV_INVALID_REPLACE, Qnil);
00544                                         i = strlcpy(tbuf, RSTRING_PTR(str), TBUFSIZE);
00545                                         tp = tbuf;
00546                                         break;
00547                                     }
00548                                 }
00549                             }
00550                             else
00551                                 i = strlen(tp);
00552                         }
00553                         break;
00554 
00555 #ifdef SYSV_EXT
00556                 case 'n':       /* same as \n */
00557                         FILL_PADDING(1);
00558                         *s++ = '\n';
00559                         continue;
00560 
00561                 case 't':       /* same as \t */
00562                         FILL_PADDING(1);
00563                         *s++ = '\t';
00564                         continue;
00565 
00566                 case 'D':       /* date as %m/%d/%y */
00567                         STRFTIME("%m/%d/%y");
00568                         continue;
00569 
00570                 case 'e':       /* day of month, blank padded */
00571                         FMT(' ', 2, "d", range(1, vtm->mday, 31));
00572                         continue;
00573 
00574                 case 'r':       /* time as %I:%M:%S %p */
00575                         STRFTIME("%I:%M:%S %p");
00576                         continue;
00577 
00578                 case 'R':       /* time as %H:%M */
00579                         STRFTIME("%H:%M");
00580                         continue;
00581 
00582                 case 'T':       /* time as %H:%M:%S */
00583                         STRFTIME("%H:%M:%S");
00584                         continue;
00585 #endif
00586 
00587 #ifdef SUNOS_EXT
00588                 case 'k':       /* hour, 24-hour clock, blank pad */
00589                         i = range(0, vtm->hour, 23);
00590                         FMT(' ', 2, "d", (int)i);
00591                         continue;
00592 
00593                 case 'l':       /* hour, 12-hour clock, 1 - 12, blank pad */
00594                         i = range(0, vtm->hour, 23);
00595                         if (i == 0)
00596                                 i = 12;
00597                         else if (i > 12)
00598                                 i -= 12;
00599                         FMT(' ', 2, "d", (int)i);
00600                         continue;
00601 #endif
00602 
00603 
00604 #ifdef VMS_EXT
00605                 case 'v':       /* date as dd-bbb-YYYY */
00606                         STRFTIME("%e-%^b-%4Y");
00607                         continue;
00608 #endif
00609 
00610 
00611 #ifdef POSIX2_DATE
00612                 case 'C':
00613                         FMTV('0', 2, "d", div(vtm->year, INT2FIX(100)));
00614                         continue;
00615 
00616                 case 'E':
00617                         /* POSIX locale extensions, ignored for now */
00618                         if (!format[1] || !strchr("cCxXyY", format[1]))
00619                                 goto unknown;
00620                         goto again;
00621                 case 'O':
00622                         /* POSIX locale extensions, ignored for now */
00623                         if (!format[1] || !strchr("deHkIlmMSuUVwWy", format[1]))
00624                                 goto unknown;
00625                         goto again;
00626 
00627                 case 'V':       /* week of year according ISO 8601 */
00628                         FMT('0', 2, "d", iso8601wknum_v(vtm));
00629                         continue;
00630 
00631                 case 'u':
00632                 /* ISO 8601: Weekday as a decimal number [1 (Monday) - 7] */
00633                         FMT('0', 1, "d", vtm->wday == 0 ? 7 : vtm->wday);
00634                         continue;
00635 #endif  /* POSIX2_DATE */
00636 
00637 #ifdef ISO_DATE_EXT
00638                 case 'G':
00639                 case 'g':
00640                         /*
00641                          * Year of ISO week.
00642                          *
00643                          * If it's December but the ISO week number is one,
00644                          * that week is in next year.
00645                          * If it's January but the ISO week number is 52 or
00646                          * 53, that week is in last year.
00647                          * Otherwise, it's this year.
00648                          */
00649                         {
00650                                 VALUE yv = vtm->year;
00651                                 w = iso8601wknum_v(vtm);
00652                                 if (vtm->mon == 12 && w == 1)
00653                                         yv = add(yv, INT2FIX(1));
00654                                 else if (vtm->mon == 1 && w >= 52)
00655                                         yv = sub(yv, INT2FIX(1));
00656 
00657                                 if (*format == 'G') {
00658                                         if (FIXNUM_P(yv)) {
00659                                                 const long y = FIX2LONG(yv);
00660                                                 FMT('0', 0 <= y ? 4 : 5, "ld", y);
00661                                         }
00662                                         else {
00663                                                 FMTV('0', 4, "d", yv);
00664                                         }
00665                                 }
00666                                 else {
00667                                         yv = mod(yv, INT2FIX(100));
00668                                         y = FIX2LONG(yv);
00669                                         FMT('0', 2, "ld", y);
00670                                 }
00671                                 continue;
00672                         }
00673 
00674 #endif /* ISO_DATE_EXT */
00675 
00676 
00677                 case 'L':
00678                         w = 3;
00679                         goto subsec;
00680 
00681                 case 'N':
00682                         /*
00683                          * fractional second digits. default is 9 digits
00684                          * (nanosecond).
00685                          *
00686                          * %3N  millisecond (3 digits)
00687                          * %6N  microsecond (6 digits)
00688                          * %9N  nanosecond (9 digits)
00689                          */
00690                         w = 9;
00691                 subsec:
00692                         if (precision <= 0) {
00693                             precision = w;
00694                         }
00695                         NEEDS(precision);
00696 
00697                         if (ts) {
00698                                 long subsec = ts->tv_nsec;
00699                                 if (9 < precision) {
00700                                         snprintf(s, endp - s, "%09ld", subsec);
00701                                         memset(s+9, '0', precision-9);
00702                                         s += precision;
00703                                 }
00704                                 else {
00705                                         int i;
00706                                         for (i = 0; i < 9-precision; i++)
00707                                                 subsec /= 10;
00708                                         snprintf(s, endp - s, "%0*ld", precision, subsec);
00709                                         s += precision;
00710                                 }
00711                         }
00712                         else {
00713                                 VALUE subsec = mod(timev, INT2FIX(1));
00714                                 int ww;
00715                                 long n;
00716 
00717                                 ww = precision;
00718                                 while (9 <= ww) {
00719                                         subsec = mul(subsec, INT2FIX(1000000000));
00720                                         ww -= 9;
00721                                 }
00722                                 n = 1;
00723                                 for (; 0 < ww; ww--)
00724                                         n *= 10;
00725                                 if (n != 1)
00726                                         subsec = mul(subsec, INT2FIX(n));
00727                                 subsec = div(subsec, INT2FIX(1));
00728 
00729                                 if (FIXNUM_P(subsec)) {
00730                                         (void)snprintf(s, endp - s, "%0*ld", precision, FIX2LONG(subsec));
00731                                         s += precision;
00732                                 }
00733                                 else {
00734                                         VALUE args[2], result;
00735                                         args[0] = INT2FIX(precision);
00736                                         args[1] = subsec;
00737                                         result = rb_str_format(2, args, rb_str_new2("%0*d"));
00738                                         (void)strlcpy(s, StringValueCStr(result), endp-s);
00739                                         s += precision;
00740                                 }
00741                         }
00742                         continue;
00743 
00744                 case 'F':       /*  Equivalent to %Y-%m-%d */
00745                         STRFTIME("%Y-%m-%d");
00746                         continue;
00747 
00748                 case '-':
00749                         FLAG_FOUND();
00750                         flags |= BIT_OF(LEFT);
00751                         padding = precision = 0;
00752                         goto again;
00753 
00754                 case '^':
00755                         FLAG_FOUND();
00756                         flags |= BIT_OF(UPPER);
00757                         goto again;
00758 
00759                 case '#':
00760                         FLAG_FOUND();
00761                         flags |= BIT_OF(CHCASE);
00762                         goto again;
00763 
00764                 case '_':
00765                         FLAG_FOUND();
00766                         padding = ' ';
00767                         goto again;
00768 
00769                 case ':':
00770                         {
00771                                 size_t l = strspn(format, ":");
00772                                 if (l > 3 || format[l] != 'z') goto unknown;
00773                                 colons = (int)l;
00774                                 format += l - 1;
00775                         }
00776                         goto again;
00777 
00778                 case '0':
00779                         padding = '0';
00780                 case '1':  case '2': case '3': case '4':
00781                 case '5': case '6':  case '7': case '8': case '9':
00782                         {
00783                                 char *e;
00784                                 precision = (int)strtoul(format, &e, 10);
00785                                 format = e - 1;
00786                                 goto again;
00787                         }
00788 
00789                 default:
00790                 unknown:
00791                         i = format - sp + 1;
00792                         tp = sp;
00793                         precision = -1;
00794                         flags = 0;
00795                         padding = 0;
00796                         colons = 0;
00797                         break;
00798                 }
00799                 if (i) {
00800                         FILL_PADDING(i);
00801                         memcpy(s, tp, i);
00802                         switch (flags & (BIT_OF(UPPER)|BIT_OF(LOWER))) {
00803                         case BIT_OF(UPPER):
00804                                 do {
00805                                         if (ISLOWER(*s)) *s = TOUPPER(*s);
00806                                 } while (s++, --i);
00807                                 break;
00808                         case BIT_OF(LOWER):
00809                                 do {
00810                                         if (ISUPPER(*s)) *s = TOLOWER(*s);
00811                                 } while (s++, --i);
00812                                 break;
00813                         default:
00814                                 s += i;
00815                                 break;
00816                         }
00817                 }
00818         }
00819         if (s >= endp) {
00820                 goto err;
00821         }
00822         if (*format == '\0') {
00823                 *s = '\0';
00824                 return (s - start);
00825         } else
00826                 return 0;
00827 }
00828 
00829 size_t
00830 rb_strftime(char *s, size_t maxsize, const char *format, rb_encoding *enc, const struct vtm *vtm, VALUE timev, int gmt)
00831 {
00832     return rb_strftime_with_timespec(s, maxsize, format, enc, vtm, timev, NULL, gmt);
00833 }
00834 
00835 size_t
00836 rb_strftime_timespec(char *s, size_t maxsize, const char *format, rb_encoding *enc, const struct vtm *vtm, struct timespec *ts, int gmt)
00837 {
00838     return rb_strftime_with_timespec(s, maxsize, format, enc, vtm, Qnil, ts, gmt);
00839 }
00840 
00841 /* isleap --- is a year a leap year? */
00842 
00843 static int
00844 isleap(long year)
00845 {
00846         return ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0);
00847 }
00848 
00849 
00850 static void
00851 vtm2tm_noyear(const struct vtm *vtm, struct tm *result)
00852 {
00853     struct tm tm;
00854 
00855     /* for isleap() in iso8601wknum.  +100 is -1900 (mod 400). */
00856     tm.tm_year = FIX2INT(mod(vtm->year, INT2FIX(400))) + 100;
00857 
00858     tm.tm_mon = vtm->mon-1;
00859     tm.tm_mday = vtm->mday;
00860     tm.tm_hour = vtm->hour;
00861     tm.tm_min = vtm->min;
00862     tm.tm_sec = vtm->sec;
00863     tm.tm_wday = vtm->wday;
00864     tm.tm_yday = vtm->yday-1;
00865     tm.tm_isdst = vtm->isdst;
00866 #if defined(HAVE_STRUCT_TM_TM_GMTOFF)
00867     tm.tm_gmtoff = NUM2LONG(vtm->utc_offset);
00868 #endif
00869 #if defined(HAVE_TM_ZONE)
00870     tm.tm_zone = (char *)vtm->zone;
00871 #endif
00872     *result = tm;
00873 }
00874 
00875 #ifdef POSIX2_DATE
00876 /* iso8601wknum --- compute week number according to ISO 8601 */
00877 
00878 static int
00879 iso8601wknum(const struct tm *timeptr)
00880 {
00881         /*
00882          * From 1003.2:
00883          *      If the week (Monday to Sunday) containing January 1
00884          *      has four or more days in the new year, then it is week 1;
00885          *      otherwise it is the highest numbered week of the previous
00886          *      year (52 or 53), and the next week is week 1.
00887          *
00888          * ADR: This means if Jan 1 was Monday through Thursday,
00889          *      it was week 1, otherwise week 52 or 53.
00890          *
00891          * XPG4 erroneously included POSIX.2 rationale text in the
00892          * main body of the standard. Thus it requires week 53.
00893          */
00894 
00895         int weeknum, jan1day;
00896 
00897         /* get week number, Monday as first day of the week */
00898         weeknum = weeknumber(timeptr, 1);
00899 
00900         /*
00901          * With thanks and tip of the hatlo to tml@tik.vtt.fi
00902          *
00903          * What day of the week does January 1 fall on?
00904          * We know that
00905          *      (timeptr->tm_yday - jan1.tm_yday) MOD 7 ==
00906          *              (timeptr->tm_wday - jan1.tm_wday) MOD 7
00907          * and that
00908          *      jan1.tm_yday == 0
00909          * and that
00910          *      timeptr->tm_wday MOD 7 == timeptr->tm_wday
00911          * from which it follows that. . .
00912          */
00913         jan1day = timeptr->tm_wday - (timeptr->tm_yday % 7);
00914         if (jan1day < 0)
00915                 jan1day += 7;
00916 
00917         /*
00918          * If Jan 1 was a Monday through Thursday, it was in
00919          * week 1.  Otherwise it was last year's highest week, which is
00920          * this year's week 0.
00921          *
00922          * What does that mean?
00923          * If Jan 1 was Monday, the week number is exactly right, it can
00924          *      never be 0.
00925          * If it was Tuesday through Thursday, the weeknumber is one
00926          *      less than it should be, so we add one.
00927          * Otherwise, Friday, Saturday or Sunday, the week number is
00928          * OK, but if it is 0, it needs to be 52 or 53.
00929          */
00930         switch (jan1day) {
00931         case 1:         /* Monday */
00932                 break;
00933         case 2:         /* Tuesday */
00934         case 3:         /* Wednesday */
00935         case 4:         /* Thursday */
00936                 weeknum++;
00937                 break;
00938         case 5:         /* Friday */
00939         case 6:         /* Saturday */
00940         case 0:         /* Sunday */
00941                 if (weeknum == 0) {
00942 #ifdef USE_BROKEN_XPG4
00943                         /* XPG4 (as of March 1994) says 53 unconditionally */
00944                         weeknum = 53;
00945 #else
00946                         /* get week number of last week of last year */
00947                         struct tm dec31ly;      /* 12/31 last year */
00948                         dec31ly = *timeptr;
00949                         dec31ly.tm_year--;
00950                         dec31ly.tm_mon = 11;
00951                         dec31ly.tm_mday = 31;
00952                         dec31ly.tm_wday = (jan1day == 0) ? 6 : jan1day - 1;
00953                         dec31ly.tm_yday = 364 + isleap(dec31ly.tm_year + 1900L);
00954                         weeknum = iso8601wknum(& dec31ly);
00955 #endif
00956                 }
00957                 break;
00958         }
00959 
00960         if (timeptr->tm_mon == 11) {
00961                 /*
00962                  * The last week of the year
00963                  * can be in week 1 of next year.
00964                  * Sigh.
00965                  *
00966                  * This can only happen if
00967                  *      M   T  W
00968                  *      29  30 31
00969                  *      30  31
00970                  *      31
00971                  */
00972                 int wday, mday;
00973 
00974                 wday = timeptr->tm_wday;
00975                 mday = timeptr->tm_mday;
00976                 if (   (wday == 1 && (mday >= 29 && mday <= 31))
00977                     || (wday == 2 && (mday == 30 || mday == 31))
00978                     || (wday == 3 &&  mday == 31))
00979                         weeknum = 1;
00980         }
00981 
00982         return weeknum;
00983 }
00984 
00985 static int
00986 iso8601wknum_v(const struct vtm *vtm)
00987 {
00988         struct tm tm;
00989         vtm2tm_noyear(vtm, &tm);
00990         return iso8601wknum(&tm);
00991 }
00992 
00993 #endif
00994 
00995 /* weeknumber --- figure how many weeks into the year */
00996 
00997 /* With thanks and tip of the hatlo to ado@elsie.nci.nih.gov */
00998 
00999 static int
01000 weeknumber(const struct tm *timeptr, int firstweekday)
01001 {
01002         int wday = timeptr->tm_wday;
01003         int ret;
01004 
01005         if (firstweekday == 1) {
01006                 if (wday == 0)  /* sunday */
01007                         wday = 6;
01008                 else
01009                         wday--;
01010         }
01011         ret = ((timeptr->tm_yday + 7 - wday) / 7);
01012         if (ret < 0)
01013                 ret = 0;
01014         return ret;
01015 }
01016 
01017 static int
01018 weeknumber_v(const struct vtm *vtm, int firstweekday)
01019 {
01020         struct tm tm;
01021         vtm2tm_noyear(vtm, &tm);
01022         return weeknumber(&tm, firstweekday);
01023 }
01024 
01025 #if 0
01026 /* ADR --- I'm loathe to mess with ado's code ... */
01027 
01028 Date:         Wed, 24 Apr 91 20:54:08 MDT
01029 From: Michal Jaegermann <audfax!emory!vm.ucs.UAlberta.CA!NTOMCZAK>
01030 To: arnold@audiofax.com
01031 
01032 Hi Arnold,
01033 in a process of fixing of strftime() in libraries on Atari ST I grabbed
01034 some pieces of code from your own strftime.  When doing that it came
01035 to mind that your weeknumber() function compiles a little bit nicer
01036 in the following form:
01037 /*
01038  * firstweekday is 0 if starting in Sunday, non-zero if in Monday
01039  */
01040 {
01041     return (timeptr->tm_yday - timeptr->tm_wday +
01042             (firstweekday ? (timeptr->tm_wday ? 8 : 1) : 7)) / 7;
01043 }
01044 How nicer it depends on a compiler, of course, but always a tiny bit.
01045 
01046    Cheers,
01047    Michal
01048    ntomczak@vm.ucs.ualberta.ca
01049 #endif
01050 
01051 #ifdef  TEST_STRFTIME
01052 
01053 /*
01054  * NAME:
01055  *      tst
01056  *
01057  * SYNOPSIS:
01058  *      tst
01059  *
01060  * DESCRIPTION:
01061  *      "tst" is a test driver for the function "strftime".
01062  *
01063  * OPTIONS:
01064  *      None.
01065  *
01066  * AUTHOR:
01067  *      Karl Vogel
01068  *      Control Data Systems, Inc.
01069  *      vogelke@c-17igp.wpafb.af.mil
01070  *
01071  * BUGS:
01072  *      None noticed yet.
01073  *
01074  * COMPILE:
01075  *      cc -o tst -DTEST_STRFTIME strftime.c
01076  */
01077 
01078 /* ADR: I reformatted this to my liking, and deleted some unneeded code. */
01079 
01080 #ifndef NULL
01081 #include        <stdio.h>
01082 #endif
01083 #include        <sys/time.h>
01084 #include        <string.h>
01085 
01086 #define         MAXTIME         132
01087 
01088 /*
01089  * Array of time formats.
01090  */
01091 
01092 static char *array[] =
01093 {
01094         "(%%A)      full weekday name, var length (Sunday..Saturday)  %A",
01095         "(%%B)       full month name, var length (January..December)  %B",
01096         "(%%C)                                               Century  %C",
01097         "(%%D)                                       date (%%m/%%d/%%y)  %D",
01098         "(%%E)                           Locale extensions (ignored)  %E",
01099         "(%%H)                          hour (24-hour clock, 00..23)  %H",
01100         "(%%I)                          hour (12-hour clock, 01..12)  %I",
01101         "(%%M)                                       minute (00..59)  %M",
01102         "(%%O)                           Locale extensions (ignored)  %O",
01103         "(%%R)                                 time, 24-hour (%%H:%%M)  %R",
01104         "(%%S)                                       second (00..60)  %S",
01105         "(%%T)                              time, 24-hour (%%H:%%M:%%S)  %T",
01106         "(%%U)    week of year, Sunday as first day of week (00..53)  %U",
01107         "(%%V)                    week of year according to ISO 8601  %V",
01108         "(%%W)    week of year, Monday as first day of week (00..53)  %W",
01109         "(%%X)     appropriate locale time representation (%H:%M:%S)  %X",
01110         "(%%Y)                           year with century (1970...)  %Y",
01111         "(%%Z) timezone (EDT), or blank if timezone not determinable  %Z",
01112         "(%%a)          locale's abbreviated weekday name (Sun..Sat)  %a",
01113         "(%%b)            locale's abbreviated month name (Jan..Dec)  %b",
01114         "(%%c)           full date (Sat Nov  4 12:02:33 1989)%n%t%t%t  %c",
01115         "(%%d)                             day of the month (01..31)  %d",
01116         "(%%e)               day of the month, blank-padded ( 1..31)  %e",
01117         "(%%h)                                should be same as (%%b)  %h",
01118         "(%%j)                            day of the year (001..366)  %j",
01119         "(%%k)               hour, 24-hour clock, blank pad ( 0..23)  %k",
01120         "(%%l)               hour, 12-hour clock, blank pad ( 1..12)  %l",
01121         "(%%m)                                        month (01..12)  %m",
01122         "(%%p)              locale's AM or PM based on 12-hour clock  %p",
01123         "(%%r)                   time, 12-hour (same as %%I:%%M:%%S %%p)  %r",
01124         "(%%u) ISO 8601: Weekday as decimal number [1 (Monday) - 7]   %u",
01125         "(%%v)                                VMS date (dd-bbb-YYYY)  %v",
01126         "(%%w)                       day of week (0..6, Sunday == 0)  %w",
01127         "(%%x)                appropriate locale date representation  %x",
01128         "(%%y)                      last two digits of year (00..99)  %y",
01129         "(%%z)      timezone offset east of GMT as HHMM (e.g. -0500)  %z",
01130         (char *) NULL
01131 };
01132 
01133 /* main routine. */
01134 
01135 int
01136 main(int argc, char **argv)
01137 {
01138         long time();
01139 
01140         char *next;
01141         char string[MAXTIME];
01142 
01143         int k;
01144         int length;
01145 
01146         struct tm *tm;
01147 
01148         long clock;
01149 
01150         /* Call the function. */
01151 
01152         clock = time((long *) 0);
01153         tm = localtime(&clock);
01154 
01155         for (k = 0; next = array[k]; k++) {
01156                 length = strftime(string, MAXTIME, next, tm);
01157                 printf("%s\n", string);
01158         }
01159 
01160         exit(0);
01161 }
01162 #endif  /* TEST_STRFTIME */
01163