First, file
1, the file system whose user-connector comprises the file name, type, attributes and operations of the files of
2, the file name: Use all operating systems allow one to eight strings consisting of characters ⺟
3, the file extension: Most operating systems support file names ⽀ Using divided into two parts separated by a dot after dot screen for part of the file name extension called
4, the file structure:
- ⽆ structure byte sequence (stream files)
- Recording a sequence of fixed ⻓
- Tree structure
5, file type
File access ****************************************** **** *************************************
********************************************** file attributes ** ************************************
File operations ******************************************* **** **********************************
Second, directory
Of Contents is important to realize the file system data structures accessed by name; file systems typically provide directory or folder for log files, many systems directory itself is a file, directory name to access important data in the file system implemented structure.
There are two files of Contents ⻅ regular structure: attribute item of Contents, and placed on the node i
1, the structure of Contents:
****************************************** single-level directory ***** *****************************
****************************************** two directories ***** **************************************
*************************************** tree directory ******** *****************************************
2, the path name: when recorded using a tree of Contents, require some files specified Remedies
3, the operation of Contents
Third, to achieve the file system
实现⽂件
⽂件系统通常是以2的n次⽅个连续的扇区为单位对⽂件进⾏磁盘空间的分配， 把分配给⽂件的连续扇区构成的磁盘块称为簇
⽂件存储的4种常⽤⽅式：
*********************************************************连续分配***************************************
把每个⽂件作为⼀连串的数据块放在磁盘上
**********************************************磁盘链接表**********************************************
*******************************************内存的链接分配表****************************************
不适合大容量的磁盘：磁盘容量大，内存连接表就越大，占用内存。
*******************************************************i-结点***********************************************
************************************************i-结点 计算题*******************************************
*******************************************计算题 2*****************************************************
2、实现⽬录
*********************************************CP/M(一种操作系统)中的目录************************************************
*********************************************MS-DOS中的目录***********************************************************
************************************************UNIX中的目录******************************************************
UNIX中采用的目录结构非常简单，每个目录项只包含一个文件名及其i结点 号。有关文件类型、长度、时间、所有者和簇号等信息都放在i结点。
3、磁盘空间管理
磁盘空间管理是文件系统的重要功能，包括记录空闲磁盘信息、设计文件的 存放方式，以及规定文件系统的簇大小等内容
4、记录空闲块的方式
