Add original unix v6

source/s1/cal.c

@@ -0,0 +1,207 @@
+char	dayw[]
+{
+	" S  M Tu  W Th  F  S"
+};
+char	*smon[]
+{
+	"Jan", "Feb", "Mar", "Apr",
+	"May", "Jun", "Jul", "Aug",
+	"Sep", "Oct", "Nov", "Dec",
+};
+char	string[432];
+main(argc, argv)
+char *argv[];
+{
+	register y, i, j;
+	int m;
+
+	if(argc < 2) {
+		printf("usage: cal [month] year\n");
+		exit();
+	}
+	if(argc == 2)
+		goto xlong;
+
+/*
+ *	print out just month
+ */
+
+	m = number(argv[1]);
+	if(m<1 || m>12)
+		goto badarg;
+	y = number(argv[2]);
+	if(y<1 || y>9999)
+		goto badarg;
+	printf("      %s %l\n", smon[m-1], y);
+	printf("%s\n", dayw);
+	cal(m, y, string, 24);
+	for(i=0; i<6*24; i=+24)
+		pstr(string+i, 24);
+	exit();
+
+/*
+ *	print out complete year
+ */
+
+xlong:
+	y = number(argv[1]);
+	if(y<1 || y>9999)
+		goto badarg;
+	printf("\n\n\n");
+	printf("				%l\n", y);
+	printf("\n");
+	for(i=0; i<12; i=+3) {
+		for(j=0; j<6*72; j++)
+			string[j] = '\0';
+		printf("	 %s", smon[i]);
+		printf("			%s", smon[i+1]);
+		printf("		       %s\n", smon[i+2]);
+		printf("%s   %s   %s\n", dayw, dayw, dayw);
+		cal(i+1, y, string, 72);
+		cal(i+2, y, string+23, 72);
+		cal(i+3, y, string+46, 72);
+		for(j=0; j<6*72; j=+72)
+			pstr(string+j, 72);
+	}
+	printf("\n\n\n");
+	exit();
+
+badarg:
+	printf("Bad argument\n");
+}
+
+number(str)
+char *str;
+{
+	register n, c;
+	register char *s;
+
+	n = 0;
+	s = str;
+	while(c = *s++) {
+		if(c<'0' || c>'9')
+			return(0);
+		n = n*10 + c-'0';
+	}
+	return(n);
+}
+
+pstr(str, n)
+char *str;
+{
+	register i;
+	register char *s;
+
+	s = str;
+	i = n;
+	while(i--)
+		if(*s++ == '\0')
+			s[-1] = ' ';
+	i = n+1;
+	while(i--)
+		if(*--s != ' ')
+			break;
+	s[1] = '\0';
+	printf("%s\n", str);
+}
+
+char	mon[]
+{
+	0,
+	31, 29, 31, 30,
+	31, 30, 31, 31,
+	30, 31, 30, 31,
+};
+
+cal(m, y, p, w)
+char *p;
+{
+	register d, i;
+	register char *s;
+
+	s = p;
+	d = jan1(y);
+	mon[2] = 29;
+	mon[9] = 30;
+
+	switch((jan1(y+1)+7-d)%7) {
+
+	/*
+	 *	non-leap year
+	 */
+	case 1:
+		mon[2] = 28;
+		break;
+
+	/*
+	 *	1752
+	 */
+	default:
+		mon[9] = 19;
+		break;
+
+	/*
+	 *	leap year
+	 */
+	case 2:
+		;
+	}
+	for(i=1; i<m; i++)
+		d =+ mon[i];
+	d =% 7;
+	s =+ 3*d;
+	for(i=1; i<=mon[m]; i++) {
+		if(i==3 & mon[m]==19) {
+			i =+ 11;
+			mon[m] =+ 11;
+		}
+		if(i > 9)
+			*s = i/10+'0';
+		s++;
+		*s++ = i%10+'0';
+		s++;
+		if(++d == 7) {
+			d = 0;
+			s = p+w;
+			p = s;
+		}
+	}
+}
+
+/*
+ *	return day of the week
+ *	of jan 1 of given year
+ */
+
+jan1(yr)
+{
+	register y, d;
+
+/*
+ *	normal gregorian calendar
+ *	one extra day per four years
+ */
+
+	y = yr;
+	d = 4+y+(y+3)/4;
+
+/*
+ *	julian calendar
+ *	regular gregorian
+ *	less three days per 400
+ */
+
+	if(y > 1800) {
+		d =- (y-1701)/100;
+		d =+ (y-1601)/400;
+	}
+
+/*
+ *	great calendar changeover instant
+ */
+
+	if(y > 1752)
+		d =+ 3;
+
+	return(d%7);
+}