Write a program to updating random access file
The file system manages access to both the content of files and the metadata about those files.
Some file systems have been designed to be used for specific applications.As a file system is used, files are created, modified and deleted.When a file is created the file system allocates space for the data.It processes physical blocks being read or written.It handles buffering and memory management and is responsible for the physical placement of blocks in specific locations on the storage medium.For 64 KB clusters, the average unused space is 32 KB.
The size of the allocation unit is chosen when the file system is created.
Choosing an allocation size that is too small results in excessive overhead if the file system will contain mostly very large files.
File system fragmentation occurs when unused space or single files are not contiguous.
In some cases, such as with tmpfs, the computer's main memory (random-access memory, RAM) is used to create a temporary file system for short-term use. Some file systems are "virtual", meaning that the supplied "files" (called virtual files) are computed on request (e.g.
procfs) or are merely a mapping into a different file system used as a backing store.
The physical file system interacts with the device drivers or with the channel to drive the storage device.