2.9BSD - /usr/src/cmd/cal.c

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

Defined functions

Defined variables