initial commitHEADmaster

1 files changed, 194 insertions, 0 deletions

diff --git a/vtime.h b/vtime.h
new file mode 100644
index 0000000..011241f
--- /dev/null
+++ b/vtime.h
@@ -0,0 +1,194 @@
+int vtime(struct tm *, const char *, int);
+
+enum vtime_flags {
+	VTIME_START_SUNDAY = 1
+};
+
+#ifdef VTIME_IMPL
+static const char * vtime_next_word(const char *);
+static const char * vtime_relative3(struct tm *, const char *, const int);
+static const char * vtime_relative2(struct tm *, const char *);
+
+static const char* vtime_day_names[] = {
+	"sunday", "monday", "tuesday", "wednesday", "thursday", "friday", "saturday"
+};
+
+int
+vtime(struct tm *tm, const char *fmt, int flags)
+{
+	int i, j, k;
+	const char *pnt;
+	for (; *fmt; fmt++) {
+		if (isblank(*fmt))
+			continue;
+
+		/* Do relative 1 */
+		if (*fmt == '+' || *fmt == '-') {
+			i = isdigit(fmt[1]) ? 0 : 1;
+			pnt = fmt+1;
+			while (isdigit(*pnt))
+				i = i * 10 + (*(pnt++) - '0');
+			if (fmt[0] == '-')
+				i = -i;
+
+			switch (tolower(*pnt)) {
+			case 'w':
+				i *= 7;
+				/* FALLTHROUGH */
+			case 'd':
+				tm->tm_mday += i;
+				break;
+			case 'm':
+				tm->tm_mon += i;
+				break;
+			case 'y':
+				tm->tm_year += i;
+				break;
+			default:
+				return 1;
+			}
+
+			fmt = pnt;
+			/* No day-time savings. We want the same relative hh:mm */
+			tm->tm_isdst = -1;
+			mktime(tm);
+			continue;
+		}
+
+		/* Absolute 1 */
+		if (isdigit(fmt[0])) {
+			i = j = k = -1;
+vtime_abs:
+			k = j;
+			j = i;
+			for (i = 0; isdigit(*fmt); fmt++)
+				i = i * 10 + (*fmt - '0');
+
+			if (!isblank(*fmt) && fmt[0]) {
+				fmt++;
+				goto vtime_abs;
+			}
+
+			if (k != -1)
+				tm->tm_year = k + (k < 100 ? (tm->tm_year / 100 * 100) : -1900);
+
+			tm->tm_mon = (j == -1) ? tm->tm_mon : j-1;
+			tm->tm_mday = i;
+
+			/* No day-time savings. We want the same relative hh:mm */
+			tm->tm_isdst = -1;
+			mktime(tm);
+			continue;
+		}
+
+		switch (tolower(fmt[0])) {
+			case 'f':
+			case 's':
+			case 'b':
+			case 'e':
+				fmt = vtime_relative3(tm, fmt, flags & VTIME_START_SUNDAY);
+				if (fmt == NULL)
+					return 1;
+				break;
+			case 'p':
+			case 'l':
+			case 'n':
+			case 't':
+				fmt = vtime_relative2(tm, fmt);
+				if (fmt == NULL)
+					return 1;
+				break;
+			default:
+				return 1;
+		}
+	}
+
+	return 0;
+}
+
+static const char *
+vtime_relative2(struct tm *tm, const char *s)
+{
+	size_t len;
+	int i, next = (s[0] == 'n') || (s[0] == 't');
+	const char *day = vtime_next_word(s);
+	if (!day[0])
+		return NULL;
+
+	for (len = 0; day[len] && !isblank(day[len]); len++);
+
+	for (i = 0; i < 7; i++) {
+		if (!strncasecmp(day, vtime_day_names[i], len))
+			break;
+	}
+
+	/* TODO: Could change to words like month/week/year/day */
+	if (i == 7)
+		return NULL;
+
+	if (next)
+		i = ((i + 13 - tm->tm_wday) % 7) + 1;
+	else
+		i = - (((tm->tm_wday - i + 13) % 7) + 1);
+
+	tm->tm_mday += i;
+	/* No day-time savings. We want the same relative hh:mm */
+	tm->tm_isdst = -1;
+	mktime(tm);
+
+
+	for (s = day; s[1] && !isblank(s[1]); s++);
+	return s;
+}
+
+static const char *
+vtime_relative3(struct tm *tm, const char *s, const int startSun)
+{
+	int i, toend = tolower(s[0]) == 'e';
+	const char *type = vtime_next_word(s);
+	switch (tolower(*type)) {
+		case 'w':
+			i = tm->tm_wday;
+			if (!startSun)
+				i = (i + 6) % 7;
+			tm->tm_mday += - i + 6 * toend;
+			break;
+		case 'm':
+			tm->tm_mday = 1;
+			if (toend) {
+				tm->tm_mon++;
+				tm->tm_mday = 0;
+			}
+			break;
+		case 'y':
+			tm->tm_mday = 1;
+			tm->tm_mon = 0;
+			if (toend) {
+				tm->tm_year++;
+				tm->tm_mday = 0;
+			}
+			break;
+		default:
+			return NULL;
+	}
+	/* No day-time savings. We want the same relative hh:mm */
+	tm->tm_isdst = -1;
+	mktime(tm);
+
+
+	for (s = type; s[1] && !isblank(s[1]); s++);
+	return s;
+}
+
+static const char *
+vtime_next_word(const char *s)
+{
+	while (*s && !isblank(*s))
+		s++;
+
+	while (isblank(*s))
+		s++;
+
+	return s;
+}
+#endif