2.9BSD - /usr/src/cmd/refer/util/shell.c

   1: shell (n, comp, exch)
   2:     int (*comp)(), (*exch)();
   3: /* SORTS UP.  IF THERE ARE NO EXCHANGES (IEX=0) ON A SWEEP
   4:   THE COMPARISON GAP (IGAP) IS HALVED FOR THE NEXT SWEEP */
   5: {
   6:     int igap, iplusg, iex, i, imax;
   7:     igap=n;
   8: while (igap > 1)
   9:     {
  10:     igap /= 2;
  11:     imax = n-igap;
  12:     do
  13:         {
  14:         iex=0;
  15:         for(i=0; i<imax; i++)
  16:             {
  17:             iplusg = i + igap;
  18:             if ((*comp) (i, iplusg) ) continue;
  19:             (*exch) (i, iplusg);
  20:             iex=1;
  21:             }
  22:         } while (iex>0);
  23:     }
  24: }

Defined functions