What is file system? and types.

A file system is a collection of files. It consists of two words file and system. The word 'file' signifies a bunch of data put some where. But the important question is where? If, for example, in a library the librarian stars keeping the books in a disorganized fashion, it will be very difficult to find a book later on. This is where 'system' come in - instead of just throwing the data to the device. We generalize and construct a system that virtualizes a nice and ordered structure in which we can arrange our data in much the same way as books are arranged our data in much  be same make it easy for us to update and maintain our data.


A file is a named collection of information that recorded on secondary storage. From user's perspective, a file is the smallest allotment of logical secondary storage. It means that data  cannot be written to secondary storage unless they are within  a file. Commonly, or binary. In general, a file represent programs and data. Data files may be numeric, alphanumeric, or binary. in general a files is a sequence of bits, bytes, lines, or records.


operation of file:- 

1. Create a file                                                                                        2. Reading from a file
3.Writing to file                                                                                      4. Repositioning within a file
5.Deleting a file                                                                                      6.Truncating a file
7.Open a file                                                                                           8.Close a file
9.Append a file                                                                                      10.Seek a file
11.Rename a file                                                                                    12.Set attributes


Attributes of file:- 

  • File name:- This is the name of file that can be read by the user.It means users identifies file by file name attributes.
  • Type:- If system is suppborting more than one types of file, type attribute is required. Different extension are used to specify the type of file like .obj,.exe,.txt,.doc,etc.
  • Size:- This attribute contains size of file in bytes of blocks.
  • Protection:- This is the attribute contains information that protect file from unauthorized users. Who will read, write,and excute the file is specify by protection attribute.
  • Location:- This is the address of location where file stored in the device.
  • Time and Date:- This information tells, when file is created and last modify and last use. This information is very valuable for usage monitoring.
  • Lock Flag:- Lock flag attribute is used to lock the file from unwanted access. Here, 0 is used for unlock and nonzero for locked.
  • Hidden Flag:- Hidden flag attribute is used to hide the flag, if flag is set no.1 it means that files will not be displayed in listing.
  • System Flag:- System flag are used to make a system file. One is used to set system flag. It shows that file is a system file.
  • Maximum Size:- This attribute is used to give information about the maximum size of file attainable to user.
  • Record Length:- It is used to provided information about the length of record to user.

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