4.3BSD - /usr/src/usr.bin/cal.c

   1: #ifndef lint
   2: static char sccsid[] = "@(#)cal.c	4.3 (Berkeley) 83/08/11";
   3: #endif
   4: 
   5: char    dayw[] = {
   6:     " S  M Tu  W Th  F  S"
   7: };
   8: char    *smon[]= {
   9:     "January", "February", "March", "April",
  10:     "May", "June", "July", "August",
  11:     "September", "October", "November", "December",
  12: };
  13: char    string[432];
  14: main(argc, argv)
  15: char *argv[];
  16: {
  17:     register y, i, j;
  18:     int m;
  19: 
  20:     if(argc < 2) {
  21:         printf("usage: cal [month] year\n");
  22:         exit(0);
  23:     }
  24:     if(argc == 2)
  25:         goto xlong;
  26: 
  27: /*
  28:  *	print out just month
  29:  */
  30: 
  31:     m = number(argv[1]);
  32:     if(m<1 || m>12)
  33:         goto badarg;
  34:     y = number(argv[2]);
  35:     if(y<1 || y>9999)
  36:         goto badarg;
  37:     printf("   %s %u\n", smon[m-1], y);
  38:     printf("%s\n", dayw);
  39:     cal(m, y, string, 24);
  40:     for(i=0; i<6*24; i+=24)
  41:         pstr(string+i, 24);
  42:     exit(0);
  43: 
  44: /*
  45:  *	print out complete year
  46:  */
  47: 
  48: xlong:
  49:     y = number(argv[1]);
  50:     if(y<1 || y>9999)
  51:         goto badarg;
  52:     printf("\n\n\n");
  53:     printf("				%u\n", y);
  54:     printf("\n");
  55:     for(i=0; i<12; i+=3) {
  56:         for(j=0; j<6*72; j++)
  57:             string[j] = '\0';
  58:         printf("	 %.3s", smon[i]);
  59:         printf("			%.3s", smon[i+1]);
  60:         printf("		       %.3s\n", smon[i+2]);
  61:         printf("%s   %s   %s\n", dayw, dayw, dayw);
  62:         cal(i+1, y, string, 72);
  63:         cal(i+2, y, string+23, 72);
  64:         cal(i+3, y, string+46, 72);
  65:         for(j=0; j<6*72; j+=72)
  66:             pstr(string+j, 72);
  67:     }
  68:     printf("\n\n\n");
  69:     exit(0);
  70: 
  71: badarg:
  72:     printf("Bad argument\n");
  73: }
  74: 
  75: number(str)
  76: char *str;
  77: {
  78:     register n, c;
  79:     register char *s;
  80: 
  81:     n = 0;
  82:     s = str;
  83:     while(c = *s++) {
  84:         if(c<'0' || c>'9')
  85:             return(0);
  86:         n = n*10 + c-'0';
  87:     }
  88:     return(n);
  89: }
  90: 
  91: pstr(str, n)
  92: char *str;
  93: {
  94:     register i;
  95:     register char *s;
  96: 
  97:     s = str;
  98:     i = n;
  99:     while(i--)
 100:         if(*s++ == '\0')
 101:             s[-1] = ' ';
 102:     i = n+1;
 103:     while(i--)
 104:         if(*--s != ' ')
 105:             break;
 106:     s[1] = '\0';
 107:     printf("%s\n", str);
 108: }
 109: 
 110: char    mon[] = {
 111:     0,
 112:     31, 29, 31, 30,
 113:     31, 30, 31, 31,
 114:     30, 31, 30, 31,
 115: };
 116: 
 117: cal(m, y, p, w)
 118: char *p;
 119: {
 120:     register d, i;
 121:     register char *s;
 122: 
 123:     s = p;
 124:     d = jan1(y);
 125:     mon[2] = 29;
 126:     mon[9] = 30;
 127: 
 128:     switch((jan1(y+1)+7-d)%7) {
 129: 
 130:     /*
 131: 	 *	non-leap year
 132: 	 */
 133:     case 1:
 134:         mon[2] = 28;
 135:         break;
 136: 
 137:     /*
 138: 	 *	1752
 139: 	 */
 140:     default:
 141:         mon[9] = 19;
 142:         break;
 143: 
 144:     /*
 145: 	 *	leap year
 146: 	 */
 147:     case 2:
 148:         ;
 149:     }
 150:     for(i=1; i<m; i++)
 151:         d += mon[i];
 152:     d %= 7;
 153:     s += 3*d;
 154:     for(i=1; i<=mon[m]; i++) {
 155:         if(i==3 && mon[m]==19) {
 156:             i += 11;
 157:             mon[m] += 11;
 158:         }
 159:         if(i > 9)
 160:             *s = i/10+'0';
 161:         s++;
 162:         *s++ = i%10+'0';
 163:         s++;
 164:         if(++d == 7) {
 165:             d = 0;
 166:             s = p+w;
 167:             p = s;
 168:         }
 169:     }
 170: }
 171: 
 172: /*
 173:  *	return day of the week
 174:  *	of jan 1 of given year
 175:  */
 176: 
 177: jan1(yr)
 178: {
 179:     register y, d;
 180: 
 181: /*
 182:  *	normal gregorian calendar
 183:  *	one extra day per four years
 184:  */
 185: 
 186:     y = yr;
 187:     d = 4+y+(y+3)/4;
 188: 
 189: /*
 190:  *	julian calendar
 191:  *	regular gregorian
 192:  *	less three days per 400
 193:  */
 194: 
 195:     if(y > 1800) {
 196:         d -= (y-1701)/100;
 197:         d += (y-1601)/400;
 198:     }
 199: 
 200: /*
 201:  *	great calendar changeover instant
 202:  */
 203: 
 204:     if(y > 1752)
 205:         d += 3;
 206: 
 207:     return(d%7);
 208: }

Defined functions

Defined variables