char**** get_pats(char *filename) {

  char fileline[MAXLINE], copyline[MAXLINE], *token;
  char ****fourfold;
  int fourfold_size = MIN_SIZE;
  int i, j;
  FILE *fp;

  fourfold = malloc((fourfold_size+1)*sizeof(char***));
  *(fourfold+fourfold_size) = NULL;

  fp = fopen(filename, "r");
  if(!fp) {
    perror("File opening failed");
    return NULL;
  }

  for (i = 0;
       fgets(fileline, sizeof(fileline), fp) != NULL;
       i++) {
    *(fourfold+i) = malloc(COLS*MAXLINE*sizeof(char));
    memcpy(copyline, fileline, MAXLINE);
    for (j = 0, token = strtok(copyline, "\t");
         token != NULL || j < 3;
         j++, token = strtok(copyline, "\t")) {
      strcpy(((char*)(*(fourfold[i])+j*COLS)), token);
    }
  }
  return fourfold;
}