+
+/* PDPC code - unreviewed, verbatim
+/* scalar date routines -- public domain by Ray Gardner
+** These will work over the range 1-01-01 thru 14699-12-31
+** The functions written by Ray are isleap, months_to_days,
+** years_to_days, ymd_to_scalar, scalar_to_ymd.
+** modified slightly by Paul Edwards
+*/
+
+static int isleap(unsigned yr)
+{
+ return yr % 400 == 0 || (yr % 4 == 0 && yr % 100 != 0);
+}
+
+static unsigned months_to_days(unsigned month)
+{
+ return (month * 3057 - 3007) / 100;
+}
+
+static long years_to_days (unsigned yr)
+{
+ return yr * 365L + yr / 4 - yr / 100 + yr / 400;
+}
+
+static long ymd_to_scalar(unsigned yr, unsigned mo, unsigned day)
+{
+ long scalar;
+
+ scalar = day + months_to_days(mo);
+ if ( mo > 2 ) /* adjust if past February */
+ scalar -= isleap(yr) ? 1 : 2;
+ yr--;
+ scalar += years_to_days(yr);
+ return (scalar);
+}
+
+static void scalar_to_ymd(long scalar,
+ unsigned *pyr,
+ unsigned *pmo,
+ unsigned *pday)
+{
+ unsigned n; /* compute inverse of years_to_days() */
+
+ n = (unsigned)((scalar * 400L) / 146097L);
+ while (years_to_days(n) < scalar)
+ {
+ n++;
+ }
+ for ( n = (unsigned)((scalar * 400L) / 146097L); years_to_days(n) < scalar; )
+ n++; /* 146097 == years_to_days(400) */
+ *pyr = n;
+ n = (unsigned)(scalar - years_to_days(n-1));
+ if ( n > 59 ) { /* adjust if past February */
+ n += 2;
+ if ( isleap(*pyr) )
+ n -= n > 62 ? 1 : 2;
+ }
+ *pmo = (n * 100 + 3007) / 3057; /* inverse of months_to_days() */
+ *pday = n - months_to_days(*pmo);
+ return;
+}
+
+time_t time(time_t *timer)
+{
+ time_t tt;
+#ifdef __OS2__
+ DATETIME dt;
+ APIRET rc;
+#endif
+#if (defined(__MSDOS__) || defined(__MVS__))
+ struct {
+ int year;
+ int month;
+ int day;
+ int hours;
+ int minutes;
+ int seconds;
+ int hundredths;
+ } dt;
+#endif
+#ifdef __MVS__
+ unsigned int clk[2];
+#endif
+
+#ifdef __OS2__
+ rc = DosGetDateTime(&dt);
+ if (rc != 0)
+ {
+ tt = (time_t)-1;
+ }
+ else
+#endif
+#ifdef __MSDOS__
+ __datetime(&dt);
+#endif
+#ifdef __MVS__
+ tt = __getclk(clk);
+#else
+
+ {
+ tt = ymd_to_scalar(dt.year, dt.month, dt.day)
+ - ymd_to_scalar(1970, 1, 1);
+ tt = tt * 24 + dt.hours;
+ tt = tt * 60 + dt.minutes;
+ tt = tt * 60 + dt.seconds;
+ }
+#endif
+ if (timer != NULL)
+ {
+ *timer = tt;
+ }
+ return (tt);
+}
+
+clock_t clock(void)
+{
+ return ((clock_t)-1);
+}
+
+double difftime(time_t time1, time_t time0)
+{
+ return ((double)(time1 - time0));
+}
+
+time_t mktime(struct tm *timeptr)
+{
+ time_t tt;
+
+ if ((timeptr->tm_year < 70) || (timeptr->tm_year > 120))
+ {
+ tt = (time_t)-1;
+ }
+ else
+ {
+ tt = ymd_to_scalar(timeptr->tm_year + 1900,
+ timeptr->tm_mon,
+ timeptr->tm_mday)
+ - ymd_to_scalar(1970, 1, 1);
+ tt = tt * 24 + timeptr->tm_hour;
+ tt = tt * 60 + timeptr->tm_min;
+ tt = tt * 60 + timeptr->tm_sec;
+ }
+ return (tt);
+}
+
+char *asctime(const struct tm *timeptr)
+{
+ static const char wday_name[7][3] = {
+ "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
+ };
+ static const char mon_name[12][3] = {
+ "Jan", "Feb", "Mar", "Apr", "May", "Jun",
+ "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
+ };
+ static char result[26];
+
+ sprintf(result, "%.3s %.3s%3d %.2d:%.2d:%.2d %d\n",
+ wday_name[timeptr->tm_wday],
+ mon_name[timeptr->tm_mon],
+ timeptr->tm_mday, timeptr->tm_hour,
+ timeptr->tm_min, timeptr->tm_sec,
+ 1900 + timeptr->tm_year);
+ return result;
+}
+
+char *ctime(const time_t *timer)
+{
+ return (asctime(localtime(timer)));
+}
+
+struct tm *gmtime(const time_t *timer)
+{
+ return (localtime(timer));
+}
+
+/* dow - written by Paul Edwards, 1993-01-31 */
+/* Released to the Public Domain */
+/* This routine will work over the range 1-01-01 to 32767-12-31.
+ It assumes the current calendar system has always been in
+ place in that time. If you pass 0 or negative years, then
+ it produces results on the assumption that there is a year
+ 0. It should always produce a value in the range of 0..6
+ if a valid month and day have been passed, no matter what
+ the year is. However, it has not been tested for negative
+ years, because the results are meaningless anyway. It is
+ mainly to stop people playing silly buggers and causing
+ the macro to crash on negative years. */
+
+/* Modified 1994-08-26 by Paul Edwards to make it return
+ 0..6 for Sunday..Saturday instead of Monday..Sunday */
+/* change the "(d) + 1" to "(d) + 0" to get it back to Monday
+ to Sunday if you want */
+
+#define dow(y,m,d) \
+ ((((((m)+9)%12+1)<<4)%27 + (d) + 1 + \
+ ((y)%400+400) + ((y)%400+400)/4 - ((y)%400+400)/100 + \
+ (((m)<=2) ? ( \
+ (((((y)%4)==0) && (((y)%100)!=0)) || (((y)%400)==0)) \
+ ? 5 : 6) : 0)) % 7)
+
+static struct tm tms;
+
+struct tm *localtime(const time_t *timer)
+{
+ unsigned yr, mo, da;
+ unsigned long secs;
+ unsigned long days;
+
+ days = *timer / (60L*60*24);
+ secs = *timer % (60L*60*24);
+ scalar_to_ymd(days + ymd_to_scalar(1970, 1, 1), &yr, &mo, &da);
+ tms.tm_year = yr - 1900;
+ tms.tm_mon = mo - 1;
+ tms.tm_mday = da;
+ tms.tm_yday = (int)(ymd_to_scalar(tms.tm_year + 1900, 1, 1)
+ - ymd_to_scalar(tms.tm_year + 1900, mo, da));
+ tms.tm_wday = dow(tms.tm_year + 1900, mo, da);
+ tms.tm_isdst = -1;
+ tms.tm_sec = (int)(secs % 60);
+ secs /= 60;
+ tms.tm_min = (int)(secs % 60);
+ secs /= 60;
+ tms.tm_hour = (int)secs;
+ return (&tms);
+}
+
+/*
+ * strftime.c
+ *
+ * implements the iso c function strftime()
+ *
+ * written 1989-09-06 by jim nutt
+ * released into the public domain by jim nutt
+ *
+ * modified 1989-10-21 by Rob Duff
+ *
+ * modified 1994-08-26 by Paul Edwards
+ */
+
+static char *aday[] = {
+ "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"
+};
+
+static char *day[] = {
+ "Sunday", "Monday", "Tuesday", "Wednesday",
+ "Thursday", "Friday", "Saturday"
+};
+
+static char *amonth[] = {
+ "Jan", "Feb", "Mar", "Apr", "May", "Jun",
+ "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
+};
+
+static char *month[] = {
+ "January", "February", "March", "April", "May", "June",
+ "July", "August", "September", "October", "November", "December"
+};
+
+static char *__tzname[2] = { "" "" };
+static char buf[26];
+
+static void strfmt(char *str, const char *fmt, ...);
+
+/**
+ *
+ * size_t strftime(char *str,
+ * size_t maxs,
+ * const char *fmt,
+ * const struct tm *t)
+ *
+ * this functions acts much like a sprintf for time/date output.
+ * given a pointer to an output buffer, a format string and a
+ * time, it copies the time to the output buffer formatted in
+ * accordance with the format string. the parameters are used
+ * as follows:
+ *
+ * str is a pointer to the output buffer, there should
+ * be at least maxs characters available at the address
+ * pointed to by str.
+ *
+ * maxs is the maximum number of characters to be copied
+ * into the output buffer, included the '\0' terminator
+ *
+ * fmt is the format string. a percent sign (%) is used
+ * to indicate that the following character is a special
+ * format character. the following are valid format
+ * characters:
+ *
+ * %A full weekday name (Monday)
+ * %a abbreviated weekday name (Mon)
+ * %B full month name (January)
+ * %b abbreviated month name (Jan)
+ * %c standard date and time representation
+ * %d day-of-month (01-31)
+ * %H hour (24 hour clock) (00-23)
+ * %I hour (12 hour clock) (01-12)
+ * %j day-of-year (001-366)
+ * %M minute (00-59)
+ * %m month (01-12)
+ * %p local equivalent of AM or PM
+ * %S second (00-59)
+ * %U week-of-year, first day sunday (00-53)
+ * %W week-of-year, first day monday (00-53)
+ * %w weekday (0-6, sunday is 0)
+ * %X standard time representation
+ * %x standard date representation
+ * %Y year with century
+ * %y year without century (00-99)
+ * %Z timezone name
+ * %% percent sign
+ *
+ * the standard date string is equivalent to:
+ *
+ * %a %b %d %Y
+ *
+ * the standard time string is equivalent to:
+ *
+ * %H:%M:%S
+ *
+ * the standard date and time string is equivalent to:
+ *
+ * %a %b %d %H:%M:%S %Y
+ *
+ * strftime returns the number of characters placed in the
+ * buffer, not including the terminating \0, or zero if more
+ * than maxs characters were produced.
+ *
+**/
+
+size_t strftime(char *s, size_t maxs, const char *f, const struct tm *t)
+{
+ int w;
+ char *p, *q, *r;
+
+ p = s;
+ q = s + maxs - 1;
+ while ((*f != '\0'))
+ {
+ if (*f++ == '%')
+ {
+ r = buf;
+ switch (*f++)
+ {
+ case '%' :
+ r = "%";
+ break;
+
+ case 'a' :
+ r = aday[t->tm_wday];
+ break;
+
+ case 'A' :
+ r = day[t->tm_wday];
+ break;
+
+ case 'b' :
+ r = amonth[t->tm_mon];
+ break;
+
+ case 'B' :
+ r = month[t->tm_mon];
+ break;
+
+ case 'c' :
+ strfmt(r, "%0 %0 %2 %2:%2:%2 %4",
+ aday[t->tm_wday], amonth[t->tm_mon],
+ t->tm_mday,t->tm_hour, t->tm_min,
+ t->tm_sec, t->tm_year+1900);
+ break;
+
+ case 'd' :
+ strfmt(r,"%2",t->tm_mday);
+ break;
+
+ case 'H' :
+ strfmt(r,"%2",t->tm_hour);
+ break;
+
+ case 'I' :
+ strfmt(r,"%2",(t->tm_hour%12)?t->tm_hour%12:12);
+ break;
+
+ case 'j' :
+ strfmt(r,"%3",t->tm_yday+1);
+ break;
+
+ case 'm' :
+ strfmt(r,"%2",t->tm_mon+1);
+ break;
+
+ case 'M' :
+ strfmt(r,"%2",t->tm_min);
+ break;
+
+ case 'p' :
+ r = (t->tm_hour>11)?"PM":"AM";
+ break;
+
+ case 'S' :
+ strfmt(r,"%2",t->tm_sec);
+ break;
+
+ case 'U' :
+ w = t->tm_yday/7;
+ if (t->tm_yday%7 > t->tm_wday)
+ w++;
+ strfmt(r, "%2", w);
+ break;
+
+ case 'W' :
+ w = t->tm_yday/7;
+ if (t->tm_yday%7 > (t->tm_wday+6)%7)
+ w++;
+ strfmt(r, "%2", w);
+ break;
+
+ case 'w' :
+ strfmt(r,"%1",t->tm_wday);
+ break;
+
+ case 'x' :
+ strfmt(r, "%3s %3s %2 %4", aday[t->tm_wday],
+ amonth[t->tm_mon], t->tm_mday, t->tm_year+1900);
+ break;
+
+ case 'X' :
+ strfmt(r, "%2:%2:%2", t->tm_hour,
+ t->tm_min, t->tm_sec);
+ break;
+
+ case 'y' :
+ strfmt(r,"%2",t->tm_year%100);
+ break;
+
+ case 'Y' :
+ strfmt(r,"%4",t->tm_year+1900);
+ break;
+
+ case 'Z' :
+ r = (t->tm_isdst) ? __tzname[1] : __tzname[0];
+ break;
+
+ default:
+ buf[0] = '%'; /* reconstruct the format */
+ buf[1] = f[-1];
+ buf[2] = '\0';
+ if (buf[1] == 0)
+ f--; /* back up if at end of string */
+ }
+ while (*r)
+ {
+ if (p == q)
+ {
+ *q = '\0';
+ return 0;
+ }
+ *p++ = *r++;
+ }
+ }
+ else
+ {
+ if (p == q)
+ {
+ *q = '\0';
+ return 0;
+ }
+ *p++ = f[-1];
+ }
+ }
+ *p = '\0';
+ return (size_t)(p - s);
+}
+
+static int pow[5] = { 1, 10, 100, 1000, 10000 };
+
+/**
+ * static void strfmt(char *str, char *fmt);
+ *
+ * simple sprintf for strftime
+ *
+ * each format descriptor is of the form %n
+ * where n goes from zero to four
+ *
+ * 0 -- string %s
+ * 1..4 -- int %?.?d
+ *
+**/
+
+static void strfmt(char *str, const char *fmt, ...)
+{
+ int ival, ilen;
+ char *sval;
+ va_list vp;
+
+ va_start(vp, fmt);
+ while (*fmt)
+ {
+ if (*fmt++ == '%')
+ {
+ ilen = *fmt++ - '0';
+ if (ilen == 0) /* zero means string arg */
+ {
+ sval = va_arg(vp, char*);
+ while (*sval)
+ *str++ = *sval++;
+ }
+ else /* always leading zeros */
+ {
+ ival = va_arg(vp, int);
+ while (ilen)
+ {
+ ival %= pow[ilen--];
+ *str++ = (char)('0' + ival / pow[ilen]);
+ }
+ }
+ }
+ else *str++ = fmt[-1];
+ }
+ *str = '\0';
+ va_end(vp);
+}
+*/
\ No newline at end of file