rc = name_search(zCmdName, aCommand, count(aCommand), &idx);
  if( rc==1 ){
    fprintf(stderr,"%s: unknown command: %s\n"
                   "%s: use \"help\" for more information\n",
                   argv[0], zCmdName, argv[0]);
    fossil_exit(1);
  }else if( rc==2 ){
    int i, n;
    Blob couldbe;
    blob_zero(&couldbe);
    n = strlen(zCmdName);
    for(i=0; i<count(aCommand); i++){
      if( memcmp(zCmdName, aCommand[i].zName, n)==0 ){
        blob_appendf(&couldbe, " %s", aCommand[i].zName);
      }
    }
    fprintf(stderr,"%s: ambiguous command prefix: %s\n"
                   "%s: could be any of:%s\n"
                   "%s: use \"help\" for more information\n",
                   argv[0], zCmdName, argv[0], blob_str(&couldbe), argv[0]);
    fossil_exit(1);
  }
  aCommand[idx].xFunc();
  fossil_exit(0);
  /*NOT_REACHED*/
  return 0;
}