- handle events that move around from year to year, i.e.,

     ``the last Monday in April'
- handle easter

new options
	-f calendarfile
	-A days
	-B days

Calendar HOME directory ~/.calendar
don't sent mail if ~/.calendar/nomail exist

1 files changed, 94 insertions, 0 deletions

diff --git a/usr.bin/calendar/ostern.c b/usr.bin/calendar/ostern.c
new file mode 100644
index 0000000..06e843b
--- /dev/null
+++ b/usr.bin/calendar/ostern.c
@@ -0,0 +1,94 @@
+/* 
+ * Copyright (c) 1995 Wolfram Schneider. Public domain.
+ *
+ * $Id: ostern.c,v 1.2 1996/02/01 13:05:12 wosch Exp $
+*/
+
+#include <string.h>
+
+/* return year day for Easter */
+
+int easter (year)
+    int year;            /* 0 ... abcd, NOT since 1900 */
+{
+
+    int e_a, e_b, e_c, e_d, e_e,e_f, e_g, e_h, e_i, e_k,
+        e_l, e_m, e_n, e_p, e_q;
+
+    /* silly, but it works */
+    e_a = year % 19;
+    e_b = year / 100;
+    e_c = year % 100;
+
+    e_d = e_b / 4;
+    e_e = e_b % 4;
+    e_f = (e_b + 8) / 25;
+    e_g = (e_b + 1 - e_f) / 3;
+    e_h = ((19 * e_a) + 15 + e_b - (e_d + e_g)) % 30;
+    e_i = e_c / 4;
+    e_k = e_c % 4;
+    e_l = (32 + 2 * e_e + 2 * e_i - (e_h + e_k)) % 7;
+    e_m = (e_a + 11 * e_h + 22 * e_l) / 451;
+    e_n = (e_h + e_l + 114 - (7 * e_m)) / 31;
+    e_p = (e_h + e_l + 114 - (7 * e_m)) % 31;
+    e_p = e_p + 1;
+
+    e_q = 31 + 28;
+
+    if (e_k == 0 && e_c != 0)
+	e_q += 1;
+
+    if (e_n == 4)
+	e_q += 31;
+
+    e_q += e_p;
+
+#if DEBUG
+    printf("%d %d %d %d %d %d %d %d %d %d %d %d %d %d %d\n", e_a , e_b , e_c , e_d , e_e , e_f , e_g , e_h , e_i , e_k , e_l , e_m , e_n  , e_p , e_q);
+#endif
+
+    return (e_q);
+}
+
+/* return year day for  Easter or easter depending days 
+ * Match: Easter([+-][0-9]+)?
+ * e.g: Easter-2 is  Good Friday (2 days before Easter)
+ */
+
+int
+geteaster(s, year)
+	char *s;
+        int year;
+{
+	register int offset = 0;
+
+#define EASTER "easter"
+#define EASTERNAMELEN (sizeof(EASTER) - 1)
+
+	/* no easter */
+	if (strncasecmp(s, EASTER, EASTERNAMELEN))
+	    return(0);
+
+#if DEBUG
+	printf("%s %d %d\n", s, year, EASTERNAMELEN);
+#endif
+
+	/* Easter+1  or Easter-2
+	 *       ^            ^   */
+
+	switch(*(s + EASTERNAMELEN)) {
+
+	case '-':
+	    offset = -(atoi(s + EASTERNAMELEN + 1));
+	    break;
+
+	case '+':
+	    offset = atoi(s + EASTERNAMELEN + 1);
+	    break;
+
+	default:
+	    offset = 0;
+	}
+	    
+	return (easter(year) + offset);
+}