code: public String getMaskString() {
  		StringBuffer buf = new StringBuffer();
  
  		if (permissions != null) {
  			int i = (int) permissions.longValue();
  			buf.append('0');
  			buf.append(octal(i, 6));
  			buf.append(octal(i, 3));
  			buf.append(octal(i, 0));
  		} else {
  			buf.append("----");
  		}
  		return buf.toString();
  	}
docs: Return the UNIX style mode mask
  
  @return mask