UNIX 6th Ed. - /usr/source/s5/qsort.c

   1: 
   2: int (*qscmp)();
   3: int qses;
   4: 
   5: qsort(a, n, es, fc)
   6: char *a;
   7: int n, es;
   8: int (*fc)();
   9: {
  10:     qscmp = fc;
  11:     qses = es;
  12:     qs1(a, a+n*es);
  13: }
  14: 
  15: qs1(a, l)
  16: char *a, *l;
  17: {
  18:     register char *i, *j, *es;
  19:     char *lp, *hp;
  20:     int n, c;
  21: 
  22: 
  23:     es = qses;
  24: 
  25: start:
  26:     if((n=l-a) <= es)
  27:         return;
  28: 
  29: 
  30:     n = ((n/(2*es))*es) & 077777;
  31:     hp = lp = a+n;
  32:     i = a;
  33:     j = l-es;
  34: 
  35: 
  36:     for(;;) {
  37:         if(i < lp) {
  38:             if((c = (*qscmp)(i, lp)) == 0) {
  39:                 qsexc(i, lp =- es);
  40:                 continue;
  41:             }
  42:             if(c < 0) {
  43:                 i =+ es;
  44:                 continue;
  45:             }
  46:         }
  47: 
  48: loop:
  49:         if(j > hp) {
  50:             if((c = (*qscmp)(hp, j)) == 0) {
  51:                 qsexc(hp =+ es, j);
  52:                 goto loop;
  53:             }
  54:             if(c > 0) {
  55:                 if(i == lp) {
  56:                     qstexc(i, hp =+ es, j);
  57:                     i = lp =+ es;
  58:                     goto loop;
  59:                 }
  60:                 qsexc(i, j);
  61:                 j =- es;
  62:                 i =+ es;
  63:                 continue;
  64:             }
  65:             j =- es;
  66:             goto loop;
  67:         }
  68: 
  69: 
  70:         if(i == lp) {
  71:             if(lp-a >= l-hp) {
  72:                 qs1(hp+es, l);
  73:                 l = lp;
  74:             } else {
  75:                 qs1(a, lp);
  76:                 a = hp+es;
  77:             }
  78:             goto start;
  79:         }
  80: 
  81: 
  82:         qstexc(j, lp =- es, i);
  83:         j = hp =- es;
  84:     }
  85: }
  86: 
  87: qsexc(i, j)
  88: char *i, *j;
  89: {
  90:     register char *ri, *rj, c;
  91:     int n;
  92: 
  93:     n = qses;
  94:     ri = i;
  95:     rj = j;
  96:     do {
  97:         c = *ri;
  98:         *ri++ = *rj;
  99:         *rj++ = c;
 100:     } while(--n);
 101: }
 102: 
 103: qstexc(i, j, k)
 104: char *i, *j, *k;
 105: {
 106:     register char *ri, *rj, *rk;
 107:     char    c;
 108:     int n;
 109: 
 110:     n = qses;
 111:     ri = i;
 112:     rj = j;
 113:     rk = k;
 114:     do {
 115:         c = *ri;
 116:         *ri++ = *rk;
 117:         *rk++ = *rj;
 118:         *rj++ = c;
 119:     } while(--n);
 120: }

Defined functions

Defined variables