date and time created 82/02/28 23:15:28 by wnj

SCCS-vsn: usr.bin/cal/cal.c 4.1

diff --git a/usr/src/usr.bin/cal/cal.c b/usr/src/usr.bin/cal/cal.c
new file mode 100644 (file)
index 0000000..1046d64
--- /dev/null
+++ b/usr/src/usr.bin/cal/cal.c
@@ -0,0 +1,205 @@
+char   *sccsid = "@(#)cal.c    4.1 4.1";
+char   dayw[] = {
+       " S  M Tu  W Th  F  S"
+};
+char   *smon[]= {
+       "January", "February", "March", "April",
+       "May", "June", "July", "August",
+       "September", "October", "November", "December",
+};
+char   string[432];
+main(argc, argv)
+char *argv[];
+{
+       register y, i, j;
+       int m;
+
+       if(argc < 2) {
+               printf("usage: cal [month] year\n");
+               exit(0);
+       }
+       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 %u\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(0);
+
+/*
+ *     print out complete year
+ */
+
+xlong:
+       y = number(argv[1]);
+       if(y<1 || y>9999)
+               goto badarg;
+       printf("\n\n\n");
+       printf("                                %u\n", y);
+       printf("\n");
+       for(i=0; i<12; i+=3) {
+               for(j=0; j<6*72; j++)
+                       string[j] = '\0';
+               printf("         %.3s", smon[i]);
+               printf("                        %.3s", smon[i+1]);
+               printf("                       %.3s\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(0);
+
+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);
+}