* strftime.c: new file.

* common.mk (COMMONOBJS): added strftime.$(OBJEXT).
* time.c (time_strftime): do not use strftime(3).  supported
  %L(millisecond) and %N(nanosecond).
* test/ruby/test_time.rb: added tests for %L and %N.


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@18731 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 924 insertions, 0 deletions

diff --git a/strftime.c b/strftime.c
new file mode 100644
index 0000000000..684e1f340e
--- /dev/null
+++ b/strftime.c
@@ -0,0 +1,924 @@
+/*
+ * strftime.c
+ *
+ * Public-domain implementation of ANSI C library routine.
+ *
+ * It's written in old-style C for maximal portability.
+ * However, since I'm used to prototypes, I've included them too.
+ *
+ * If you want stuff in the System V ascftime routine, add the SYSV_EXT define.
+ * For extensions from SunOS, add SUNOS_EXT.
+ * For stuff needed to implement the P1003.2 date command, add POSIX2_DATE.
+ * For VMS dates, add VMS_EXT.
+ * For a an RFC822 time format, add MAILHEADER_EXT.
+ * For ISO week years, add ISO_DATE_EXT.
+ * For complete POSIX semantics, add POSIX_SEMANTICS.
+ *
+ * The code for %c, %x, and %X now follows the 1003.2 specification for
+ * the POSIX locale.
+ * This version ignores LOCALE information.
+ * It also doesn't worry about multi-byte characters.
+ * So there.
+ *
+ * This file is also shipped with GAWK (GNU Awk), gawk specific bits of
+ * code are included if GAWK is defined.
+ *
+ * Arnold Robbins
+ * January, February, March, 1991
+ * Updated March, April 1992
+ * Updated April, 1993
+ * Updated February, 1994
+ * Updated May, 1994
+ * Updated January, 1995
+ * Updated September, 1995
+ * Updated January, 1996
+ *
+ * Fixes from ado@elsie.nci.nih.gov
+ * February 1991, May 1992
+ * Fixes from Tor Lillqvist tml@tik.vtt.fi
+ * May, 1993
+ * Further fixes from ado@elsie.nci.nih.gov
+ * February 1994
+ * %z code from chip@chinacat.unicom.com
+ * Applied September 1995
+ * %V code fixed (again) and %G, %g added,
+ * January 1996
+ */
+
+#include "ruby/ruby.h"
+
+#ifndef GAWK
+#include <stdio.h>
+#include <ctype.h>
+#include <string.h>
+#include <time.h>
+#include <sys/types.h>
+#include <errno.h>
+#endif
+#if defined(TM_IN_SYS_TIME) || !defined(GAWK) && !defined(_WIN32_WCE)
+#include <sys/types.h>
+#include <sys/time.h>
+#endif
+
+/* defaults: season to taste */
+#define SYSV_EXT	1	/* stuff in System V ascftime routine */
+#define SUNOS_EXT	1	/* stuff in SunOS strftime routine */
+#define POSIX2_DATE	1	/* stuff in Posix 1003.2 date command */
+#define VMS_EXT		1	/* include %v for VMS date format */
+#define MAILHEADER_EXT	1	/* add %z for HHMM format */
+#define ISO_DATE_EXT	1	/* %G and %g for year of ISO week */
+#ifndef GAWK
+#define POSIX_SEMANTICS	1	/* call tzset() if TZ changes */
+#endif
+
+#if defined(ISO_DATE_EXT)
+#if ! defined(POSIX2_DATE)
+#define POSIX2_DATE	1
+#endif
+#endif
+
+#if defined(POSIX2_DATE)
+#if ! defined(SYSV_EXT)
+#define SYSV_EXT	1
+#endif
+#if ! defined(SUNOS_EXT)
+#define SUNOS_EXT	1
+#endif
+#endif
+
+#if defined(POSIX2_DATE)
+#define adddecl(stuff)	stuff
+#else
+#define adddecl(stuff)
+#endif
+
+#undef strchr	/* avoid AIX weirdness */
+
+#ifndef __STDC__
+#define const	/**/
+extern void tzset();
+static int weeknumber();
+adddecl(static int iso8601wknum();)
+#else
+extern void tzset(void);
+static int weeknumber(const struct tm *timeptr, int firstweekday);
+adddecl(static int iso8601wknum(const struct tm *timeptr);)
+#endif
+
+#ifdef STDC_HEADERS
+#include <stdlib.h>
+#include <string.h>
+#else
+extern void *malloc();
+extern void *realloc();
+extern char *getenv();
+extern char *strchr();
+#endif
+
+#define range(low, item, hi)	max(low, min(item, hi))
+
+#ifdef __CYGWIN__
+#define DLL_IMPORT __declspec(dllimport)
+#endif
+#ifdef __WIN32__
+#define DLL_IMPORT __declspec(dllimport)
+#endif
+#ifndef DLL_IMPORT
+#define DLL_IMPORT
+#endif
+#if !defined(OS2) && !defined(MSDOS) && defined(HAVE_TZNAME)
+extern DLL_IMPORT char *tzname[2];
+#ifdef HAVE_DAYLIGHT
+extern DLL_IMPORT int daylight;
+#endif
+#ifdef HAVE_VAR_TIMEZONE
+extern DLL_IMPORT TYPEOF_VAR_TIMEZONE timezone;
+#endif
+#ifdef HAVE_VAR_ALTZONE
+extern DLL_IMPORT TYPEOF_VAR_ALTZONE altzone;
+#endif
+#endif
+
+#undef min	/* just in case */
+
+/* min --- return minimum of two numbers */
+
+#ifndef __STDC__
+static inline int
+min(a, b)
+int a, b;
+#else
+static inline int
+min(int a, int b)
+#endif
+{
+	return (a < b ? a : b);
+}
+
+#undef max	/* also, just in case */
+
+/* max --- return maximum of two numbers */
+
+#ifndef __STDC__
+static inline int
+max(a, b)
+int a, b;
+#else
+static inline int
+max(int a, int b)
+#endif
+{
+	return (a > b ? a : b);
+}
+
+/* strftime --- produce formatted time */
+
+size_t
+rb_strftime(char *s, size_t maxsize, const char *format, const struct tm *timeptr, const struct timespec *ts, int gmt)
+{
+	char *endp = s + maxsize;
+	char *start = s;
+	auto char tbuf[100];
+	long off;
+	int i, w;
+	long y;
+	static short first = 1;
+#ifdef POSIX_SEMANTICS
+	static char *savetz = NULL;
+	static int savetzlen = 0;
+	char *tz;
+#endif /* POSIX_SEMANTICS */
+#ifndef HAVE_TM_ZONE
+#ifndef HAVE_TM_NAME
+	struct timeval tv;
+	struct timezone zone;
+#endif /* HAVE_TM_NAME */
+#endif /* HAVE_TM_ZONE */
+
+	/* various tables, useful in North America */
+	static const char *days_a[] = {
+		"Sun", "Mon", "Tue", "Wed",
+		"Thu", "Fri", "Sat",
+	};
+	static const char *days_l[] = {
+		"Sunday", "Monday", "Tuesday", "Wednesday",
+		"Thursday", "Friday", "Saturday",
+	};
+	static const char *months_a[] = {
+		"Jan", "Feb", "Mar", "Apr", "May", "Jun",
+		"Jul", "Aug", "Sep", "Oct", "Nov", "Dec",
+	};
+	static const char *months_l[] = {
+		"January", "February", "March", "April",
+		"May", "June", "July", "August", "September",
+		"October", "November", "December",
+	};
+	static const char *ampm[] = { "AM", "PM", };
+
+	if (s == NULL || format == NULL || timeptr == NULL || maxsize == 0)
+		return 0;
+
+	/* quick check if we even need to bother */
+	if (strchr(format, '%') == NULL && strlen(format) + 1 >= maxsize) {
+		errno = ERANGE;
+		return 0;
+	}
+
+#ifndef POSIX_SEMANTICS
+	if (first) {
+		tzset();
+		first = 0;
+	}
+#else	/* POSIX_SEMANTICS */
+	tz = getenv("TZ");
+	if (first) {
+		if (tz != NULL) {
+			int tzlen = strlen(tz);
+
+			savetz = (char *) malloc(tzlen + 1);
+			if (savetz != NULL) {
+				savetzlen = tzlen + 1;
+				strcpy(savetz, tz);
+			}
+		}
+		tzset();
+		first = 0;
+	}
+	/* if we have a saved TZ, and it is different, recapture and reset */
+	if (tz && savetz && (tz[0] != savetz[0] || strcmp(tz, savetz) != 0)) {
+		i = strlen(tz) + 1;
+		if (i > savetzlen) {
+			savetz = (char *) realloc(savetz, i);
+			if (savetz) {
+				savetzlen = i;
+				strcpy(savetz, tz);
+			}
+		} else
+			strcpy(savetz, tz);
+		tzset();
+	}
+#endif	/* POSIX_SEMANTICS */
+
+	for (; *format && s < endp - 1; format++) {
+		tbuf[0] = '\0';
+		if (*format != '%') {
+			*s++ = *format;
+			continue;
+		}
+	again:
+		switch (*++format) {
+		case '\0':
+			*s++ = '%';
+			goto out;
+
+		case '%':
+			*s++ = '%';
+			continue;
+
+		case 'a':	/* abbreviated weekday name */
+			if (timeptr->tm_wday < 0 || timeptr->tm_wday > 6)
+				strcpy(tbuf, "?");
+			else
+				strcpy(tbuf, days_a[timeptr->tm_wday]);
+			break;
+
+		case 'A':	/* full weekday name */
+			if (timeptr->tm_wday < 0 || timeptr->tm_wday > 6)
+				strcpy(tbuf, "?");
+			else
+				strcpy(tbuf, days_l[timeptr->tm_wday]);
+			break;
+
+#ifdef SYSV_EXT
+		case 'h':	/* abbreviated month name */
+#endif
+		case 'b':	/* abbreviated month name */
+			if (timeptr->tm_mon < 0 || timeptr->tm_mon > 11)
+				strcpy(tbuf, "?");
+			else
+				strcpy(tbuf, months_a[timeptr->tm_mon]);
+			break;
+
+		case 'B':	/* full month name */
+			if (timeptr->tm_mon < 0 || timeptr->tm_mon > 11)
+				strcpy(tbuf, "?");
+			else
+				strcpy(tbuf, months_l[timeptr->tm_mon]);
+			break;
+
+		case 'c':	/* appropriate date and time representation */
+			strftime(tbuf, sizeof tbuf, "%a %b %e %H:%M:%S %Y", timeptr);
+			break;
+
+		case 'd':	/* day of the month, 01 - 31 */
+			i = range(1, timeptr->tm_mday, 31);
+			sprintf(tbuf, "%02d", i);
+			break;
+
+		case 'H':	/* hour, 24-hour clock, 00 - 23 */
+			i = range(0, timeptr->tm_hour, 23);
+			sprintf(tbuf, "%02d", i);
+			break;
+
+		case 'I':	/* hour, 12-hour clock, 01 - 12 */
+			i = range(0, timeptr->tm_hour, 23);
+			if (i == 0)
+				i = 12;
+			else if (i > 12)
+				i -= 12;
+			sprintf(tbuf, "%02d", i);
+			break;
+
+		case 'j':	/* day of the year, 001 - 366 */
+			sprintf(tbuf, "%03d", timeptr->tm_yday + 1);
+			break;
+
+		case 'm':	/* month, 01 - 12 */
+			i = range(0, timeptr->tm_mon, 11);
+			sprintf(tbuf, "%02d", i + 1);
+			break;
+
+		case 'M':	/* minute, 00 - 59 */
+			i = range(0, timeptr->tm_min, 59);
+			sprintf(tbuf, "%02d", i);
+			break;
+
+		case 'p':	/* am or pm based on 12-hour clock */
+			i = range(0, timeptr->tm_hour, 23);
+			if (i < 12)
+				strcpy(tbuf, ampm[0]);
+			else
+				strcpy(tbuf, ampm[1]);
+			break;
+
+		case 'S':	/* second, 00 - 60 */
+			i = range(0, timeptr->tm_sec, 60);
+			sprintf(tbuf, "%02d", i);
+			break;
+
+		case 'U':	/* week of year, Sunday is first day of week */
+			sprintf(tbuf, "%02d", weeknumber(timeptr, 0));
+			break;
+
+		case 'w':	/* weekday, Sunday == 0, 0 - 6 */
+			i = range(0, timeptr->tm_wday, 6);
+			sprintf(tbuf, "%d", i);
+			break;
+
+		case 'W':	/* week of year, Monday is first day of week */
+			sprintf(tbuf, "%02d", weeknumber(timeptr, 1));
+			break;
+
+		case 'x':	/* appropriate date representation */
+			strftime(tbuf, sizeof tbuf, "%m/%d/%y", timeptr);
+			break;
+
+		case 'X':	/* appropriate time representation */
+			strftime(tbuf, sizeof tbuf, "%H:%M:%S", timeptr);
+			break;
+
+		case 'y':	/* year without a century, 00 - 99 */
+			i = timeptr->tm_year % 100;
+			sprintf(tbuf, "%02d", i);
+			break;
+
+		case 'Y':	/* year with century */
+			sprintf(tbuf, "%ld", 1900L + timeptr->tm_year);
+			break;
+
+#ifdef MAILHEADER_EXT
+		/*
+		 * From: Chip Rosenthal <chip@chinacat.unicom.com>
+		 * Date: Sun, 19 Mar 1995 00:33:29 -0600 (CST)
+		 * 
+		 * Warning: the %z [code] is implemented by inspecting the
+		 * timezone name conditional compile settings, and
+		 * inferring a method to get timezone offsets. I've tried
+		 * this code on a couple of machines, but I don't doubt
+		 * there is some system out there that won't like it.
+		 * Maybe the easiest thing to do would be to bracket this
+		 * with an #ifdef that can turn it off. The %z feature
+		 * would be an admittedly obscure one that most folks can
+		 * live without, but it would be a great help to those of
+		 * us that muck around with various message processors.
+		 */
+ 		case 'z':	/* time zone offset east of GMT e.g. -0600 */
+			if (gmt) {
+			    strcpy(tbuf, "+0000");
+			    break;
+			}
+#ifdef HAVE_TM_NAME
+			/*
+			 * Systems with tm_name probably have tm_tzadj as
+			 * secs west of GMT.  Convert to mins east of GMT.
+			 */
+			off = -timeptr->tm_tzadj / 60;
+#else /* !HAVE_TM_NAME */
+#ifdef HAVE_TM_ZONE
+			/*
+			 * Systems with tm_zone probably have tm_gmtoff as
+			 * secs east of GMT.  Convert to mins east of GMT.
+			 */
+			off = timeptr->tm_gmtoff / 60;
+#else /* !HAVE_TM_ZONE */
+#ifdef HAVE_GETTIMEOFDAY
+			gettimeofday(&tv, &zone);
+			off = -zone.tz_minuteswest;
+#else
+#if HAVE_VAR_TIMEZONE
+#if HAVE_VAR_ALTZONE
+			off = -(daylight ? timezone : altzone) / 60;
+#else
+			off = -timezone / 60;
+#endif
+#endif
+#endif
+#endif /* !HAVE_TM_ZONE */
+#endif /* !HAVE_TM_NAME */
+			if (off < 0) {
+				tbuf[0] = '-';
+				off = -off;
+			} else {
+				tbuf[0] = '+';
+			}
+			sprintf(tbuf+1, "%02u%02u", (unsigned)off/60, (unsigned)off%60);
+			break;
+#endif /* MAILHEADER_EXT */
+
+		case 'Z':	/* time zone name or abbrevation */
+			if (gmt) {
+			    strcpy(tbuf, "GMT");
+			    break;
+			}
+#ifdef HAVE_TZNAME
+			i = (daylight && timeptr->tm_isdst > 0); /* 0 or 1 */
+			strcpy(tbuf, tzname[i]);
+#else
+#ifdef HAVE_TM_ZONE
+			strcpy(tbuf, timeptr->tm_zone);
+#else
+#ifdef HAVE_TM_NAME
+			strcpy(tbuf, timeptr->tm_name);
+#else
+#ifdef HAVE_TIMEZONE
+			gettimeofday(& tv, & zone);
+#ifdef TIMEZONE_VOID
+			strcpy(tbuf, timezone());
+#else
+			strcpy(tbuf, timezone(zone.tz_minuteswest,
+						timeptr->tm_isdst > 0));
+#endif /* TIMEZONE_VOID */
+#endif /* HAVE_TIMEZONE */
+#endif /* HAVE_TM_NAME */
+#endif /* HAVE_TM_ZONE */
+#endif /* HAVE_TZNAME */
+			break;
+
+#ifdef SYSV_EXT
+		case 'n':	/* same as \n */
+			tbuf[0] = '\n';
+			tbuf[1] = '\0';
+			break;
+
+		case 't':	/* same as \t */
+			tbuf[0] = '\t';
+			tbuf[1] = '\0';
+			break;
+
+		case 'D':	/* date as %m/%d/%y */
+			strftime(tbuf, sizeof tbuf, "%m/%d/%y", timeptr);
+			break;
+
+		case 'e':	/* day of month, blank padded */
+			sprintf(tbuf, "%2d", range(1, timeptr->tm_mday, 31));
+			break;
+
+		case 'r':	/* time as %I:%M:%S %p */
+			strftime(tbuf, sizeof tbuf, "%I:%M:%S %p", timeptr);
+			break;
+
+		case 'R':	/* time as %H:%M */
+			strftime(tbuf, sizeof tbuf, "%H:%M", timeptr);
+			break;
+
+		case 'T':	/* time as %H:%M:%S */
+			strftime(tbuf, sizeof tbuf, "%H:%M:%S", timeptr);
+			break;
+#endif
+
+#ifdef SUNOS_EXT
+		case 'k':	/* hour, 24-hour clock, blank pad */
+			sprintf(tbuf, "%2d", range(0, timeptr->tm_hour, 23));
+			break;
+
+		case 'l':	/* hour, 12-hour clock, 1 - 12, blank pad */
+			i = range(0, timeptr->tm_hour, 23);
+			if (i == 0)
+				i = 12;
+			else if (i > 12)
+				i -= 12;
+			sprintf(tbuf, "%2d", i);
+			break;
+#endif
+
+
+#ifdef VMS_EXT
+		case 'v':	/* date as dd-bbb-YYYY */
+			sprintf(tbuf, "%2d-%3.3s-%4ld",
+				range(1, timeptr->tm_mday, 31),
+				months_a[range(0, timeptr->tm_mon, 11)],
+				timeptr->tm_year + 1900L);
+			for (i = 3; i < 6; i++)
+				if (islower(tbuf[i]))
+					tbuf[i] = toupper(tbuf[i]);
+			break;
+#endif
+
+
+#ifdef POSIX2_DATE
+		case 'C':
+			sprintf(tbuf, "%02ld", (timeptr->tm_year + 1900L) / 100);
+			break;
+
+
+		case 'E':
+		case 'O':
+			/* POSIX locale extensions, ignored for now */
+			goto again;
+
+		case 'V':	/* week of year according ISO 8601 */
+			sprintf(tbuf, "%02d", iso8601wknum(timeptr));
+			break;
+
+		case 'u':
+		/* ISO 8601: Weekday as a decimal number [1 (Monday) - 7] */
+			sprintf(tbuf, "%d", timeptr->tm_wday == 0 ? 7 :
+					timeptr->tm_wday);
+			break;
+#endif	/* POSIX2_DATE */
+
+#ifdef ISO_DATE_EXT
+		case 'G':
+		case 'g':
+			/*
+			 * Year of ISO week.
+			 *
+			 * If it's December but the ISO week number is one,
+			 * that week is in next year.
+			 * If it's January but the ISO week number is 52 or
+			 * 53, that week is in last year.
+			 * Otherwise, it's this year.
+			 */
+			w = iso8601wknum(timeptr);
+			if (timeptr->tm_mon == 11 && w == 1)
+				y = 1900L + timeptr->tm_year + 1;
+			else if (timeptr->tm_mon == 0 && w >= 52)
+				y = 1900L + timeptr->tm_year - 1;
+			else
+				y = 1900L + timeptr->tm_year;
+
+			if (*format == 'G')
+				sprintf(tbuf, "%ld", y);
+			else
+				sprintf(tbuf, "%02ld", y % 100);
+			break;
+#endif /* ISO_DATE_EXT */
+
+		case 'L':	/* millisecond, 000 - 999 */
+			sprintf(tbuf, "%03ld", ts->tv_nsec / 1000000);
+			break;
+
+		case 'N':	/* nanosecond, 000000000 - 999999999 */
+			sprintf(tbuf, "%09ld", ts->tv_nsec);
+			break;
+
+		default:
+			tbuf[0] = '%';
+			tbuf[1] = *format;
+			tbuf[2] = '\0';
+			break;
+		}
+		i = strlen(tbuf);
+		if (i) {
+			if (s + i < endp - 1) {
+				strcpy(s, tbuf);
+				s += i;
+			} else {
+				errno = ERANGE;
+				return 0;
+			}
+		}
+	}
+out:
+	if (s >= endp) {
+		errno = ERANGE;
+		return 0;
+	}
+	if (*format == '\0') {
+		*s = '\0';
+		return (s - start);
+	} else
+		return 0;
+}
+
+/* isleap --- is a year a leap year? */
+
+#ifndef __STDC__
+static int
+isleap(year)
+long year;
+#else
+static int
+isleap(long year)
+#endif
+{
+	return ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0);
+}
+
+
+#ifdef POSIX2_DATE
+/* iso8601wknum --- compute week number according to ISO 8601 */
+
+#ifndef __STDC__
+static int
+iso8601wknum(timeptr)
+const struct tm *timeptr;
+#else
+static int
+iso8601wknum(const struct tm *timeptr)
+#endif
+{
+	/*
+	 * From 1003.2:
+	 *	If the week (Monday to Sunday) containing January 1
+	 *	has four or more days in the new year, then it is week 1;
+	 *	otherwise it is the highest numbered week of the previous
+	 *	year (52 or 53), and the next week is week 1.
+	 *
+	 * ADR: This means if Jan 1 was Monday through Thursday,
+	 *	it was week 1, otherwise week 52 or 53.
+	 *
+	 * XPG4 erroneously included POSIX.2 rationale text in the
+	 * main body of the standard. Thus it requires week 53.
+	 */
+
+	int weeknum, jan1day;
+
+	/* get week number, Monday as first day of the week */
+	weeknum = weeknumber(timeptr, 1);
+
+	/*
+	 * With thanks and tip of the hatlo to tml@tik.vtt.fi
+	 *
+	 * What day of the week does January 1 fall on?
+	 * We know that
+	 *	(timeptr->tm_yday - jan1.tm_yday) MOD 7 ==
+	 *		(timeptr->tm_wday - jan1.tm_wday) MOD 7
+	 * and that
+	 * 	jan1.tm_yday == 0
+	 * and that
+	 * 	timeptr->tm_wday MOD 7 == timeptr->tm_wday
+	 * from which it follows that. . .
+ 	 */
+	jan1day = timeptr->tm_wday - (timeptr->tm_yday % 7);
+	if (jan1day < 0)
+		jan1day += 7;
+
+	/*
+	 * If Jan 1 was a Monday through Thursday, it was in
+	 * week 1.  Otherwise it was last year's highest week, which is
+	 * this year's week 0.
+	 *
+	 * What does that mean?
+	 * If Jan 1 was Monday, the week number is exactly right, it can
+	 *	never be 0.
+	 * If it was Tuesday through Thursday, the weeknumber is one
+	 *	less than it should be, so we add one.
+	 * Otherwise, Friday, Saturday or Sunday, the week number is
+	 * OK, but if it is 0, it needs to be 52 or 53.
+	 */
+	switch (jan1day) {
+	case 1:		/* Monday */
+		break;
+	case 2:		/* Tuesday */
+	case 3:		/* Wednesday */
+	case 4:		/* Thursday */
+		weeknum++;
+		break;
+	case 5:		/* Friday */
+	case 6:		/* Saturday */
+	case 0:		/* Sunday */
+		if (weeknum == 0) {
+#ifdef USE_BROKEN_XPG4
+			/* XPG4 (as of March 1994) says 53 unconditionally */
+			weeknum = 53;
+#else
+			/* get week number of last week of last year */
+			struct tm dec31ly;	/* 12/31 last year */
+			dec31ly = *timeptr;
+			dec31ly.tm_year--;
+			dec31ly.tm_mon = 11;
+			dec31ly.tm_mday = 31;
+			dec31ly.tm_wday = (jan1day == 0) ? 6 : jan1day - 1;
+			dec31ly.tm_yday = 364 + isleap(dec31ly.tm_year + 1900L);
+			weeknum = iso8601wknum(& dec31ly);
+#endif
+		}
+		break;
+	}
+
+	if (timeptr->tm_mon == 11) {
+		/*
+		 * The last week of the year
+		 * can be in week 1 of next year.
+		 * Sigh.
+		 *
+		 * This can only happen if
+		 *	M   T  W
+		 *	29  30 31
+		 *	30  31
+		 *	31
+		 */
+		int wday, mday;
+
+		wday = timeptr->tm_wday;
+		mday = timeptr->tm_mday;
+		if (   (wday == 1 && (mday >= 29 && mday <= 31))
+		    || (wday == 2 && (mday == 30 || mday == 31))
+		    || (wday == 3 &&  mday == 31))
+			weeknum = 1;
+	}
+
+	return weeknum;
+}
+#endif
+
+/* weeknumber --- figure how many weeks into the year */
+
+/* With thanks and tip of the hatlo to ado@elsie.nci.nih.gov */
+
+#ifndef __STDC__
+static int
+weeknumber(timeptr, firstweekday)
+const struct tm *timeptr;
+int firstweekday;
+#else
+static int
+weeknumber(const struct tm *timeptr, int firstweekday)
+#endif
+{
+	int wday = timeptr->tm_wday;
+	int ret;
+
+	if (firstweekday == 1) {
+		if (wday == 0)	/* sunday */
+			wday = 6;
+		else
+			wday--;
+	}
+	ret = ((timeptr->tm_yday + 7 - wday) / 7);
+	if (ret < 0)
+		ret = 0;
+	return ret;
+}
+
+#if 0
+/* ADR --- I'm loathe to mess with ado's code ... */
+
+Date:         Wed, 24 Apr 91 20:54:08 MDT
+From: Michal Jaegermann <audfax!emory!vm.ucs.UAlberta.CA!NTOMCZAK>
+To: arnold@audiofax.com
+
+Hi Arnold,
+in a process of fixing of strftime() in libraries on Atari ST I grabbed
+some pieces of code from your own strftime.  When doing that it came
+to mind that your weeknumber() function compiles a little bit nicer
+in the following form:
+/*
+ * firstweekday is 0 if starting in Sunday, non-zero if in Monday
+ */
+{
+    return (timeptr->tm_yday - timeptr->tm_wday +
+	    (firstweekday ? (timeptr->tm_wday ? 8 : 1) : 7)) / 7;
+}
+How nicer it depends on a compiler, of course, but always a tiny bit.
+
+   Cheers,
+   Michal
+   ntomczak@vm.ucs.ualberta.ca
+#endif
+
+#ifdef	TEST_STRFTIME
+
+/*
+ * NAME:
+ *	tst
+ *
+ * SYNOPSIS:
+ *	tst
+ *
+ * DESCRIPTION:
+ *	"tst" is a test driver for the function "strftime".
+ *
+ * OPTIONS:
+ *	None.
+ *
+ * AUTHOR:
+ *	Karl Vogel
+ *	Control Data Systems, Inc.
+ *	vogelke@c-17igp.wpafb.af.mil
+ *
+ * BUGS:
+ *	None noticed yet.
+ *
+ * COMPILE:
+ *	cc -o tst -DTEST_STRFTIME strftime.c
+ */
+
+/* ADR: I reformatted this to my liking, and deleted some unneeded code. */
+
+#ifndef NULL
+#include	<stdio.h>
+#endif
+#include	<sys/time.h>
+#include	<string.h>
+
+#define		MAXTIME		132
+
+/*
+ * Array of time formats.
+ */
+
+static char *array[] =
+{
+	"(%%A)      full weekday name, var length (Sunday..Saturday)  %A",
+	"(%%B)       full month name, var length (January..December)  %B",
+	"(%%C)                                               Century  %C",
+	"(%%D)                                       date (%%m/%%d/%%y)  %D",
+	"(%%E)                           Locale extensions (ignored)  %E",
+	"(%%H)                          hour (24-hour clock, 00..23)  %H",
+	"(%%I)                          hour (12-hour clock, 01..12)  %I",
+	"(%%M)                                       minute (00..59)  %M",
+	"(%%O)                           Locale extensions (ignored)  %O",
+	"(%%R)                                 time, 24-hour (%%H:%%M)  %R",
+	"(%%S)                                       second (00..60)  %S",
+	"(%%T)                              time, 24-hour (%%H:%%M:%%S)  %T",
+	"(%%U)    week of year, Sunday as first day of week (00..53)  %U",
+	"(%%V)                    week of year according to ISO 8601  %V",
+	"(%%W)    week of year, Monday as first day of week (00..53)  %W",
+	"(%%X)     appropriate locale time representation (%H:%M:%S)  %X",
+	"(%%Y)                           year with century (1970...)  %Y",
+	"(%%Z) timezone (EDT), or blank if timezone not determinable  %Z",
+	"(%%a)          locale's abbreviated weekday name (Sun..Sat)  %a",
+	"(%%b)            locale's abbreviated month name (Jan..Dec)  %b",
+	"(%%c)           full date (Sat Nov  4 12:02:33 1989)%n%t%t%t  %c",
+	"(%%d)                             day of the month (01..31)  %d",
+	"(%%e)               day of the month, blank-padded ( 1..31)  %e",
+	"(%%h)                                should be same as (%%b)  %h",
+	"(%%j)                            day of the year (001..366)  %j",
+	"(%%k)               hour, 24-hour clock, blank pad ( 0..23)  %k",
+	"(%%l)               hour, 12-hour clock, blank pad ( 0..12)  %l",
+	"(%%m)                                        month (01..12)  %m",
+	"(%%p)              locale's AM or PM based on 12-hour clock  %p",
+	"(%%r)                   time, 12-hour (same as %%I:%%M:%%S %%p)  %r",
+	"(%%u) ISO 8601: Weekday as decimal number [1 (Monday) - 7]   %u",
+	"(%%v)                                VMS date (dd-bbb-YYYY)  %v",
+	"(%%w)                       day of week (0..6, Sunday == 0)  %w",
+	"(%%x)                appropriate locale date representation  %x",
+	"(%%y)                      last two digits of year (00..99)  %y",
+	"(%%z)      timezone offset east of GMT as HHMM (e.g. -0500)  %z",
+	(char *) NULL
+};
+
+/* main routine. */
+
+int
+main(argc, argv)
+int argc;
+char **argv;
+{
+	long time();
+
+	char *next;
+	char string[MAXTIME];
+
+	int k;
+	int length;
+
+	struct tm *tm;
+
+	long clock;
+
+	/* Call the function. */
+
+	clock = time((long *) 0);
+	tm = localtime(&clock);
+
+	for (k = 0; next = array[k]; k++) {
+		length = strftime(string, MAXTIME, next, tm);
+		printf("%s\n", string);
+	}
+
+	exit(0);
+}
+#endif	/* TEST_STRFTIME */