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[gb-231r1-is01/GB_2.3_IS01.git] / system / core / libcutils / tzstrftime.c
diff --git a/system/core/libcutils/tzstrftime.c b/system/core/libcutils/tzstrftime.c
new file mode 100644 (file)
index 0000000..e37d79a
--- /dev/null
@@ -0,0 +1,841 @@
+#ifndef lint
+#ifndef NOID
+static char    elsieid[] = "@(#)strftime.c     8.1";
+/*
+** Based on the UCB version with the ID appearing below.
+** This is ANSIish only when "multibyte character == plain character".
+*/
+#endif /* !defined NOID */
+#endif /* !defined lint */
+
+#include <time.h>
+#include <tzfile.h>
+#include <limits.h>
+#include <cutils/tztime.h>
+
+/*
+** Copyright (c) 1989 The Regents of the University of California.
+** All rights reserved.
+**
+** Redistribution and use in source and binary forms are permitted
+** provided that the above copyright notice and this paragraph are
+** duplicated in all such forms and that any documentation,
+** advertising materials, and other materials related to such
+** distribution and use acknowledge that the software was developed
+** by the University of California, Berkeley. The name of the
+** University may not be used to endorse or promote products derived
+** from this software without specific prior written permission.
+** THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
+** IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
+** WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+*/
+
+#ifndef LIBC_SCCS
+#ifndef lint
+static const char      sccsid[] = "@(#)strftime.c      5.4 (Berkeley) 3/14/89";
+#endif /* !defined lint */
+#endif /* !defined LIBC_SCCS */
+
+#include <ctype.h>
+
+#define P(x) x
+
+static char *  _add P((const char *, char *, const char *, int));
+static char *  _conv P((int, const char *, char *, const char *));
+static char *  _fmt P((const char *, const struct tm *, char *, const char *,
+                       int *, const struct strftime_locale *Locale));
+static char *  _yconv P((int, int, int, int, char *, const char *, int));
+static char *  getformat P((int, char *, char *, char *, char *));
+
+extern char *  tzname[];
+
+
+
+
+
+/* from private.h */
+
+#ifndef TYPE_BIT
+#define TYPE_BIT(type)  (sizeof (type) * CHAR_BIT)
+#endif /* !defined TYPE_BIT */
+
+#ifndef TYPE_SIGNED
+#define TYPE_SIGNED(type) (((type) -1) < 0)
+#endif /* !defined TYPE_SIGNED */
+
+#ifndef INT_STRLEN_MAXIMUM
+/*
+ * ** 302 / 1000 is log10(2.0) rounded up.
+ * ** Subtract one for the sign bit if the type is signed;
+ * ** add one for integer division truncation;
+ * ** add one more for a minus sign if the type is signed.
+ * */
+#define INT_STRLEN_MAXIMUM(type) \
+    ((TYPE_BIT(type) - TYPE_SIGNED(type)) * 302 / 1000 + \
+    1 + TYPE_SIGNED(type))
+#endif /* !defined INT_STRLEN_MAXIMUM */
+
+/* end of part from private.h */
+
+
+
+
+#ifndef YEAR_2000_NAME
+#define YEAR_2000_NAME "CHECK_STRFTIME_FORMATS_FOR_TWO_DIGIT_YEARS"
+#endif /* !defined YEAR_2000_NAME */
+
+#define IN_NONE        0
+#define IN_SOME        1
+#define IN_THIS        2
+#define IN_ALL 3
+
+#define FORCE_LOWER_CASE 0x100
+
+size_t
+strftime_tz(s, maxsize, format, t, Locale)
+char * const           s;
+const size_t           maxsize;
+const char * const     format;
+const struct tm * const        t;
+const struct strftime_locale *Locale;
+{
+       char *  p;
+       int     warn;
+
+       warn = IN_NONE;
+       p = _fmt(((format == NULL) ? "%c" : format), t, s, s + maxsize, &warn, Locale);
+#if 0
+       if (warn != IN_NONE && getenv(YEAR_2000_NAME) != NULL) {
+               (void) fprintf(stderr, "\n");
+               if (format == NULL)
+                       (void) fprintf(stderr, "NULL strftime format ");
+               else    (void) fprintf(stderr, "strftime format \"%s\" ",
+                               format);
+               (void) fprintf(stderr, "yields only two digits of years in ");
+               if (warn == IN_SOME)
+                       (void) fprintf(stderr, "some locales");
+               else if (warn == IN_THIS)
+                       (void) fprintf(stderr, "the current locale");
+               else    (void) fprintf(stderr, "all locales");
+               (void) fprintf(stderr, "\n");
+       }
+#endif /* !defined NO_RUN_TIME_WARNINGS_ABOUT_YEAR_2000_PROBLEMS_THANK_YOU */
+       if (p == s + maxsize)
+               return 0;
+       *p = '\0';
+       return p - s;
+}
+
+static char *getformat(int modifier, char *normal, char *underscore,
+                       char *dash, char *zero) {
+    switch (modifier) {
+    case '_':
+        return underscore;
+
+    case '-':
+        return dash;
+
+    case '0':
+        return zero;
+    }
+
+    return normal;
+}
+
+static char *
+_fmt(format, t, pt, ptlim, warnp, Locale)
+const char *           format;
+const struct tm * const        t;
+char *                 pt;
+const char * const     ptlim;
+int *                  warnp;
+const struct strftime_locale *Locale;
+{
+       for ( ; *format; ++format) {
+               if (*format == '%') {
+            int modifier = 0;
+label:
+                       switch (*++format) {
+                       case '\0':
+                               --format;
+                               break;
+                       case 'A':
+                               pt = _add((t->tm_wday < 0 ||
+                                       t->tm_wday >= DAYSPERWEEK) ?
+                                       "?" : Locale->weekday[t->tm_wday],
+                                       pt, ptlim, modifier);
+                               continue;
+                       case 'a':
+                               pt = _add((t->tm_wday < 0 ||
+                                       t->tm_wday >= DAYSPERWEEK) ?
+                                       "?" : Locale->wday[t->tm_wday],
+                                       pt, ptlim, modifier);
+                               continue;
+                       case 'B':
+                               if (modifier == '-') {
+                                       pt = _add((t->tm_mon < 0 ||
+                                               t->tm_mon >= MONSPERYEAR) ?
+                                               "?" : Locale->standalone_month[t->tm_mon],
+                                               pt, ptlim, modifier);
+                               } else {
+                                       pt = _add((t->tm_mon < 0 ||
+                                               t->tm_mon >= MONSPERYEAR) ?
+                                               "?" : Locale->month[t->tm_mon],
+                                               pt, ptlim, modifier);
+                               }
+                               continue;
+                       case 'b':
+                       case 'h':
+                               pt = _add((t->tm_mon < 0 ||
+                                       t->tm_mon >= MONSPERYEAR) ?
+                                       "?" : Locale->mon[t->tm_mon],
+                                       pt, ptlim, modifier);
+                               continue;
+                       case 'C':
+                               /*
+                               ** %C used to do a...
+                               **      _fmt("%a %b %e %X %Y", t);
+                               ** ...whereas now POSIX 1003.2 calls for
+                               ** something completely different.
+                               ** (ado, 1993-05-24)
+                               */
+                               pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 0,
+                                       pt, ptlim, modifier);
+                               continue;
+                       case 'c':
+                               {
+                               int warn2 = IN_SOME;
+
+                               pt = _fmt(Locale->c_fmt, t, pt, ptlim, warnp, Locale);
+                               if (warn2 == IN_ALL)
+                                       warn2 = IN_THIS;
+                               if (warn2 > *warnp)
+                                       *warnp = warn2;
+                               }
+                               continue;
+                       case 'D':
+                                pt = _fmt("%m/%d/%y", t, pt, ptlim, warnp, Locale);
+                               continue;
+                       case 'd':
+                                pt = _conv(t->tm_mday,
+                                           getformat(modifier, "%02d",
+                                                     "%2d", "%d", "%02d"),
+                                           pt, ptlim);
+                               continue;
+                       case 'E':
+                       case 'O':
+                               /*
+                               ** C99 locale modifiers.
+                               ** The sequences
+                               **      %Ec %EC %Ex %EX %Ey %EY
+                               **      %Od %oe %OH %OI %Om %OM
+                               **      %OS %Ou %OU %OV %Ow %OW %Oy
+                               ** are supposed to provide alternate
+                               ** representations.
+                               */
+                               goto label;
+            case '_':
+            case '-':
+            case '0':
+            case '^':
+            case '#':
+                modifier = *format;
+                goto label;
+                       case 'e':
+                               pt = _conv(t->tm_mday,
+                                           getformat(modifier, "%2d",
+                                                     "%2d", "%d", "%02d"),
+                                           pt, ptlim);
+                               continue;
+                       case 'F':
+                               pt = _fmt("%Y-%m-%d", t, pt, ptlim, warnp, Locale);
+                               continue;
+                       case 'H':
+                               pt = _conv(t->tm_hour,
+                                           getformat(modifier, "%02d",
+                                                     "%2d", "%d", "%02d"),
+                                           pt, ptlim);
+                               continue;
+                       case 'I':
+                               pt = _conv((t->tm_hour % 12) ?
+                                       (t->tm_hour % 12) : 12,
+                                       getformat(modifier, "%02d",
+                                                  "%2d", "%d", "%02d"),
+                                        pt, ptlim);
+                               continue;
+                       case 'j':
+                               pt = _conv(t->tm_yday + 1,
+                           getformat(modifier, "%03d", "%3d", "%d", "%03d"),
+                           pt, ptlim);
+                               continue;
+                       case 'k':
+                               /*
+                               ** This used to be...
+                               **      _conv(t->tm_hour % 12 ?
+                               **              t->tm_hour % 12 : 12, 2, ' ');
+                               ** ...and has been changed to the below to
+                               ** match SunOS 4.1.1 and Arnold Robbins'
+                               ** strftime version 3.0. That is, "%k" and
+                               ** "%l" have been swapped.
+                               ** (ado, 1993-05-24)
+                               */
+                               pt = _conv(t->tm_hour,
+                                           getformat(modifier, "%2d",
+                                                     "%2d", "%d", "%02d"),
+                                           pt, ptlim);
+                               continue;
+#ifdef KITCHEN_SINK
+                       case 'K':
+                               /*
+                               ** After all this time, still unclaimed!
+                               */
+                               pt = _add("kitchen sink", pt, ptlim, modifier);
+                               continue;
+#endif /* defined KITCHEN_SINK */
+                       case 'l':
+                               /*
+                               ** This used to be...
+                               **      _conv(t->tm_hour, 2, ' ');
+                               ** ...and has been changed to the below to
+                               ** match SunOS 4.1.1 and Arnold Robbin's
+                               ** strftime version 3.0. That is, "%k" and
+                               ** "%l" have been swapped.
+                               ** (ado, 1993-05-24)
+                               */
+                               pt = _conv((t->tm_hour % 12) ?
+                                       (t->tm_hour % 12) : 12,
+                                       getformat(modifier, "%2d",
+                                                  "%2d", "%d", "%02d"),
+                                        pt, ptlim);
+                               continue;
+                       case 'M':
+                               pt = _conv(t->tm_min,
+                                           getformat(modifier, "%02d",
+                                                     "%2d", "%d", "%02d"),
+                                           pt, ptlim);
+                               continue;
+                       case 'm':
+                               pt = _conv(t->tm_mon + 1,
+                                           getformat(modifier, "%02d",
+                                                     "%2d", "%d", "%02d"),
+                                           pt, ptlim);
+                               continue;
+                       case 'n':
+                               pt = _add("\n", pt, ptlim, modifier);
+                               continue;
+                       case 'p':
+                               pt = _add((t->tm_hour >= (HOURSPERDAY / 2)) ?
+                                       Locale->pm :
+                                       Locale->am,
+                                       pt, ptlim, modifier);
+                               continue;
+                       case 'P':
+                               pt = _add((t->tm_hour >= (HOURSPERDAY / 2)) ?
+                                       Locale->pm :
+                                       Locale->am,
+                                       pt, ptlim, FORCE_LOWER_CASE);
+                               continue;
+                       case 'R':
+                               pt = _fmt("%H:%M", t, pt, ptlim, warnp, Locale);
+                               continue;
+                       case 'r':
+                               pt = _fmt("%I:%M:%S %p", t, pt, ptlim, warnp, Locale);
+                               continue;
+                       case 'S':
+                               pt = _conv(t->tm_sec,
+                                           getformat(modifier, "%02d",
+                                                     "%2d", "%d", "%02d"),
+                                           pt, ptlim);
+                               continue;
+                       case 's':
+                               {
+                                       struct tm       tm;
+                                       char            buf[INT_STRLEN_MAXIMUM(
+                                                               time_t) + 1];
+                                       time_t          mkt;
+
+                                       tm = *t;
+                                       mkt = mktime(&tm);
+                                       if (TYPE_SIGNED(time_t))
+                                               (void) sprintf(buf, "%ld",
+                                                       (long) mkt);
+                                       else    (void) sprintf(buf, "%lu",
+                                                       (unsigned long) mkt);
+                                       pt = _add(buf, pt, ptlim, modifier);
+                               }
+                               continue;
+                       case 'T':
+                               pt = _fmt("%H:%M:%S", t, pt, ptlim, warnp, Locale);
+                               continue;
+                       case 't':
+                               pt = _add("\t", pt, ptlim, modifier);
+                               continue;
+                       case 'U':
+                               pt = _conv((t->tm_yday + DAYSPERWEEK -
+                                       t->tm_wday) / DAYSPERWEEK,
+                                       getformat(modifier, "%02d",
+                                                  "%2d", "%d", "%02d"),
+                                        pt, ptlim);
+                               continue;
+                       case 'u':
+                               /*
+                               ** From Arnold Robbins' strftime version 3.0:
+                               ** "ISO 8601: Weekday as a decimal number
+                               ** [1 (Monday) - 7]"
+                               ** (ado, 1993-05-24)
+                               */
+                               pt = _conv((t->tm_wday == 0) ?
+                                       DAYSPERWEEK : t->tm_wday, "%d", pt, ptlim);
+                               continue;
+                       case 'V':       /* ISO 8601 week number */
+                       case 'G':       /* ISO 8601 year (four digits) */
+                       case 'g':       /* ISO 8601 year (two digits) */
+/*
+** From Arnold Robbins' strftime version 3.0: "the week number of the
+** year (the first Monday as the first day of week 1) as a decimal number
+** (01-53)."
+** (ado, 1993-05-24)
+**
+** From "http://www.ft.uni-erlangen.de/~mskuhn/iso-time.html" by Markus Kuhn:
+** "Week 01 of a year is per definition the first week which has the
+** Thursday in this year, which is equivalent to the week which contains
+** the fourth day of January. In other words, the first week of a new year
+** is the week which has the majority of its days in the new year. Week 01
+** might also contain days from the previous year and the week before week
+** 01 of a year is the last week (52 or 53) of the previous year even if
+** it contains days from the new year. A week starts with Monday (day 1)
+** and ends with Sunday (day 7). For example, the first week of the year
+** 1997 lasts from 1996-12-30 to 1997-01-05..."
+** (ado, 1996-01-02)
+*/
+                               {
+                                       int     year;
+                                       int     base;
+                                       int     yday;
+                                       int     wday;
+                                       int     w;
+
+                                       year = t->tm_year;
+                                       base = TM_YEAR_BASE;
+                                       yday = t->tm_yday;
+                                       wday = t->tm_wday;
+                                       for ( ; ; ) {
+                                               int     len;
+                                               int     bot;
+                                               int     top;
+
+                                               len = isleap_sum(year, base) ?
+                                                       DAYSPERLYEAR :
+                                                       DAYSPERNYEAR;
+                                               /*
+                                               ** What yday (-3 ... 3) does
+                                               ** the ISO year begin on?
+                                               */
+                                               bot = ((yday + 11 - wday) %
+                                                       DAYSPERWEEK) - 3;
+                                               /*
+                                               ** What yday does the NEXT
+                                               ** ISO year begin on?
+                                               */
+                                               top = bot -
+                                                       (len % DAYSPERWEEK);
+                                               if (top < -3)
+                                                       top += DAYSPERWEEK;
+                                               top += len;
+                                               if (yday >= top) {
+                                                       ++base;
+                                                       w = 1;
+                                                       break;
+                                               }
+                                               if (yday >= bot) {
+                                                       w = 1 + ((yday - bot) /
+                                                               DAYSPERWEEK);
+                                                       break;
+                                               }
+                                               --base;
+                                               yday += isleap_sum(year, base) ?
+                                                       DAYSPERLYEAR :
+                                                       DAYSPERNYEAR;
+                                       }
+#ifdef XPG4_1994_04_09
+                                       if ((w == 52 &&
+                                               t->tm_mon == TM_JANUARY) ||
+                                               (w == 1 &&
+                                               t->tm_mon == TM_DECEMBER))
+                                                       w = 53;
+#endif /* defined XPG4_1994_04_09 */
+                                       if (*format == 'V')
+                                               pt = _conv(w,
+                                                           getformat(modifier,
+                                                                     "%02d",
+                                                                     "%2d",
+                                                                     "%d",
+                                                                     "%02d"),
+                                                          pt, ptlim);
+                                       else if (*format == 'g') {
+                                               *warnp = IN_ALL;
+                                               pt = _yconv(year, base, 0, 1,
+                                                       pt, ptlim, modifier);
+                                       } else  pt = _yconv(year, base, 1, 1,
+                                                       pt, ptlim, modifier);
+                               }
+                               continue;
+                       case 'v':
+                               /*
+                               ** From Arnold Robbins' strftime version 3.0:
+                               ** "date as dd-bbb-YYYY"
+                               ** (ado, 1993-05-24)
+                               */
+                               pt = _fmt("%e-%b-%Y", t, pt, ptlim, warnp, Locale);
+                               continue;
+                       case 'W':
+                               pt = _conv((t->tm_yday + DAYSPERWEEK -
+                                       (t->tm_wday ?
+                                       (t->tm_wday - 1) :
+                                       (DAYSPERWEEK - 1))) / DAYSPERWEEK,
+                                       getformat(modifier, "%02d",
+                                                  "%2d", "%d", "%02d"),
+                                        pt, ptlim);
+                               continue;
+                       case 'w':
+                               pt = _conv(t->tm_wday, "%d", pt, ptlim);
+                               continue;
+                       case 'X':
+                               pt = _fmt(Locale->X_fmt, t, pt, ptlim, warnp, Locale);
+                               continue;
+                       case 'x':
+                               {
+                               int     warn2 = IN_SOME;
+
+                               pt = _fmt(Locale->x_fmt, t, pt, ptlim, &warn2, Locale);
+                               if (warn2 == IN_ALL)
+                                       warn2 = IN_THIS;
+                               if (warn2 > *warnp)
+                                       *warnp = warn2;
+                               }
+                               continue;
+                       case 'y':
+                               *warnp = IN_ALL;
+                               pt = _yconv(t->tm_year, TM_YEAR_BASE, 0, 1,
+                                       pt, ptlim, modifier);
+                               continue;
+                       case 'Y':
+                               pt = _yconv(t->tm_year, TM_YEAR_BASE, 1, 1,
+                                       pt, ptlim, modifier);
+                               continue;
+                       case 'Z':
+#ifdef TM_ZONE
+                               if (t->TM_ZONE != NULL)
+                                       pt = _add(t->TM_ZONE, pt, ptlim,
+                                                  modifier);
+                               else
+#endif /* defined TM_ZONE */
+                               if (t->tm_isdst >= 0)
+                                       pt = _add(tzname[t->tm_isdst != 0],
+                                               pt, ptlim, modifier);
+                               /*
+                               ** C99 says that %Z must be replaced by the
+                               ** empty string if the time zone is not
+                               ** determinable.
+                               */
+                               continue;
+                       case 'z':
+                               {
+                               int             diff;
+                               char const *    sign;
+
+                               if (t->tm_isdst < 0)
+                                       continue;
+#ifdef TM_GMTOFF
+                               diff = t->TM_GMTOFF;
+#else /* !defined TM_GMTOFF */
+                               /*
+                               ** C99 says that the UTC offset must
+                               ** be computed by looking only at
+                               ** tm_isdst. This requirement is
+                               ** incorrect, since it means the code
+                               ** must rely on magic (in this case
+                               ** altzone and timezone), and the
+                               ** magic might not have the correct
+                               ** offset. Doing things correctly is
+                               ** tricky and requires disobeying C99;
+                               ** see GNU C strftime for details.
+                               ** For now, punt and conform to the
+                               ** standard, even though it's incorrect.
+                               **
+                               ** C99 says that %z must be replaced by the
+                               ** empty string if the time zone is not
+                               ** determinable, so output nothing if the
+                               ** appropriate variables are not available.
+                               */
+                               if (t->tm_isdst == 0)
+#ifdef USG_COMPAT
+                                       diff = -timezone;
+#else /* !defined USG_COMPAT */
+                                       continue;
+#endif /* !defined USG_COMPAT */
+                               else
+#ifdef ALTZONE
+                                       diff = -altzone;
+#else /* !defined ALTZONE */
+                                       continue;
+#endif /* !defined ALTZONE */
+#endif /* !defined TM_GMTOFF */
+                               if (diff < 0) {
+                                       sign = "-";
+                                       diff = -diff;
+                               } else  sign = "+";
+                               pt = _add(sign, pt, ptlim, modifier);
+                               diff /= SECSPERMIN;
+                               diff = (diff / MINSPERHOUR) * 100 +
+                                       (diff % MINSPERHOUR);
+                               pt = _conv(diff,
+                                           getformat(modifier, "%04d",
+                                                     "%4d", "%d", "%04d"),
+                                           pt, ptlim);
+                               }
+                               continue;
+                       case '+':
+                               pt = _fmt(Locale->date_fmt, t, pt, ptlim,
+                                       warnp, Locale);
+                               continue;
+                       case '%':
+                       /*
+                       ** X311J/88-090 (4.12.3.5): if conversion char is
+                       ** undefined, behavior is undefined. Print out the
+                       ** character itself as printf(3) also does.
+                       */
+                       default:
+                               break;
+                       }
+               }
+               if (pt == ptlim)
+                       break;
+               *pt++ = *format;
+       }
+       return pt;
+}
+
+static char *
+_conv(n, format, pt, ptlim)
+const int              n;
+const char * const     format;
+char * const           pt;
+const char * const     ptlim;
+{
+       char    buf[INT_STRLEN_MAXIMUM(int) + 1];
+
+       (void) sprintf(buf, format, n);
+       return _add(buf, pt, ptlim, 0);
+}
+
+static char *
+_add(str, pt, ptlim, modifier)
+const char *           str;
+char *                 pt;
+const char * const     ptlim;
+int                     modifier;
+{
+        int c;
+
+        switch (modifier) {
+        case FORCE_LOWER_CASE:
+                while (pt < ptlim && (*pt = tolower(*str++)) != '\0') {
+                        ++pt;
+                }
+                break;
+
+        case '^':
+                while (pt < ptlim && (*pt = toupper(*str++)) != '\0') {
+                        ++pt;
+                }
+                break;
+
+        case '#':
+                while (pt < ptlim && (c = *str++) != '\0') {
+                        if (isupper(c)) {
+                                c = tolower(c);
+                        } else if (islower(c)) {
+                                c = toupper(c);
+                        }
+                        *pt = c;
+                        ++pt;
+                }
+
+                break;
+
+        default:
+                while (pt < ptlim && (*pt = *str++) != '\0') {
+                        ++pt;
+                }
+        }
+
+       return pt;
+}
+
+/*
+** POSIX and the C Standard are unclear or inconsistent about
+** what %C and %y do if the year is negative or exceeds 9999.
+** Use the convention that %C concatenated with %y yields the
+** same output as %Y, and that %Y contains at least 4 bytes,
+** with more only if necessary.
+*/
+
+static char *
+_yconv(a, b, convert_top, convert_yy, pt, ptlim, modifier)
+const int              a;
+const int              b;
+const int              convert_top;
+const int              convert_yy;
+char *                 pt;
+const char * const     ptlim;
+int                     modifier;
+{
+       register int    lead;
+       register int    trail;
+
+#define DIVISOR        100
+       trail = a % DIVISOR + b % DIVISOR;
+       lead = a / DIVISOR + b / DIVISOR + trail / DIVISOR;
+       trail %= DIVISOR;
+       if (trail < 0 && lead > 0) {
+               trail += DIVISOR;
+               --lead;
+       } else if (lead < 0 && trail > 0) {
+               trail -= DIVISOR;
+               ++lead;
+       }
+       if (convert_top) {
+               if (lead == 0 && trail < 0)
+                       pt = _add("-0", pt, ptlim, modifier);
+               else    pt = _conv(lead, getformat(modifier, "%02d",
+                                                   "%2d", "%d", "%02d"),
+                                   pt, ptlim);
+       }
+       if (convert_yy)
+               pt = _conv(((trail < 0) ? -trail : trail),
+                           getformat(modifier, "%02d", "%2d", "%d", "%02d"),
+                           pt, ptlim);
+       return pt;
+}
+
+#ifdef LOCALE_HOME
+static struct lc_time_T *
+_loc P((void))
+{
+       static const char       locale_home[] = LOCALE_HOME;
+       static const char       lc_time[] = "LC_TIME";
+       static char *           locale_buf;
+
+       int                     fd;
+       int                     oldsun; /* "...ain't got nothin' to do..." */
+       char *                  lbuf;
+       char *                  name;
+       char *                  p;
+       const char **           ap;
+       const char *            plim;
+       char                    filename[FILENAME_MAX];
+       struct stat             st;
+       size_t                  namesize;
+       size_t                  bufsize;
+
+       /*
+       ** Use localebuf.mon[0] to signal whether locale is already set up.
+       */
+       if (localebuf.mon[0])
+               return &localebuf;
+       name = setlocale(LC_TIME, (char *) NULL);
+       if (name == NULL || *name == '\0')
+               goto no_locale;
+       /*
+       ** If the locale name is the same as our cache, use the cache.
+       */
+       lbuf = locale_buf;
+       if (lbuf != NULL && strcmp(name, lbuf) == 0) {
+               p = lbuf;
+               for (ap = (const char **) &localebuf;
+                       ap < (const char **) (&localebuf + 1);
+                               ++ap)
+                                       *ap = p += strlen(p) + 1;
+               return &localebuf;
+       }
+       /*
+       ** Slurp the locale file into the cache.
+       */
+       namesize = strlen(name) + 1;
+       if (sizeof filename <
+               ((sizeof locale_home) + namesize + (sizeof lc_time)))
+                       goto no_locale;
+       oldsun = 0;
+       (void) sprintf(filename, "%s/%s/%s", locale_home, name, lc_time);
+       fd = open(filename, O_RDONLY);
+       if (fd < 0) {
+               /*
+               ** Old Sun systems have a different naming and data convention.
+               */
+               oldsun = 1;
+               (void) sprintf(filename, "%s/%s/%s", locale_home,
+                       lc_time, name);
+               fd = open(filename, O_RDONLY);
+               if (fd < 0)
+                       goto no_locale;
+       }
+       if (fstat(fd, &st) != 0)
+               goto bad_locale;
+       if (st.st_size <= 0)
+               goto bad_locale;
+       bufsize = namesize + st.st_size;
+       locale_buf = NULL;
+       lbuf = (lbuf == NULL) ? malloc(bufsize) : realloc(lbuf, bufsize);
+       if (lbuf == NULL)
+               goto bad_locale;
+       (void) strcpy(lbuf, name);
+       p = lbuf + namesize;
+       plim = p + st.st_size;
+       if (read(fd, p, (size_t) st.st_size) != st.st_size)
+               goto bad_lbuf;
+       if (close(fd) != 0)
+               goto bad_lbuf;
+       /*
+       ** Parse the locale file into localebuf.
+       */
+       if (plim[-1] != '\n')
+               goto bad_lbuf;
+       for (ap = (const char **) &localebuf;
+               ap < (const char **) (&localebuf + 1);
+                       ++ap) {
+                               if (p == plim)
+                                       goto bad_lbuf;
+                               *ap = p;
+                               while (*p != '\n')
+                                       ++p;
+                               *p++ = '\0';
+       }
+       if (oldsun) {
+               /*
+               ** SunOS 4 used an obsolescent format; see localdtconv(3).
+               ** c_fmt had the ``short format for dates and times together''
+               ** (SunOS 4 date, "%a %b %e %T %Z %Y" in the C locale);
+               ** date_fmt had the ``long format for dates''
+               ** (SunOS 4 strftime %C, "%A, %B %e, %Y" in the C locale).
+               ** Discard the latter in favor of the former.
+               */
+               localebuf.date_fmt = localebuf.c_fmt;
+       }
+       /*
+       ** Record the successful parse in the cache.
+       */
+       locale_buf = lbuf;
+
+       return &localebuf;
+
+bad_lbuf:
+       free(lbuf);
+bad_locale:
+       (void) close(fd);
+no_locale:
+       localebuf = C_time_locale;
+       locale_buf = NULL;
+       return &localebuf;
+}
+#endif /* defined LOCALE_HOME */