Home | | Operating Systems | File System Storage

File System Storage - | Study Material, Lecturing Notes, Assignment, Reference, Wiki description explanation, brief detail |

Chapter: Operating Systems - File Systems

File System Storage

A file is a named collection of related information that is recorded on secondary storage.

FILE SYSTEM STORAGE

 

1 File Concept

 

ü A file is a named collection of related information that is recorded on secondary storage.

 

ü From a user’s perspective, a file is the smallest allotment of logical secondary storage; that is, data cannot be written to secondary storage unless they are within a file.

 

   Examples of files:

 

   A text file is a sequence of characters organized into lines (and possibly pages).

 

   A source file is a sequence of subroutines and functions, each of which is further organized as declarations followed by executable statements. An object file is a sequence of bytes organized into blocks understandable by the system’s linker. An executable file is a series of code sections that the loader can bring into memory and execute.

 

2 File Attributes

 

            Name: The symbolic file name is the only information kept in human readable form.

 

            Identifier: This unique tag, usually a number identifies the file within the file system. It is the non-human readable name for the file.

 

            Type: This information is needed for those systems that support different types.

 

            Location: This information is a pointer to a device and to the location of the file on that device.

 

            Size: The current size of the file (in bytes, words or blocks)and possibly the maximum allowed size are included in this attribute.

 

            Protection: Access-control information determines who can do reading, writing, executing and so on.

 

            Time, date and user identification: This information may be kept for creation, last modification and last use. These data can be useful for protection, security and usage monitoring.

 

3 File Operations

 

v Creating a file

v Reading a file

 

v Repositioning within a file

 

v Deleting a file

 

v Truncating a file

 

4 File Types




 

Study Material, Lecturing Notes, Assignment, Reference, Wiki description explanation, brief detail


Copyright © 2018-2021 BrainKart.com; All Rights Reserved. (BS) Developed by Therithal info, Chennai.