CODEWITHSUNDEEP
operating-systemfilenames
Blastosphere
Blastosphere

Reputation: 361

Where are Filenames and other File Properties stored in OS's?

I was wondering some time ago, where are filenames and modification dates stored in Operating System.

For instance, when you create a text file in Windows, and you give it a name, when you look at the binary form using a tool like Frhed, there won't be anything (besides the text content)

  1. Is there a folder with all files names and dates?

  2. Supposing your friend sends you a text file, how do you get the filename (and other file properties) in your computer?

Upvotes: 0

Views: 858

Answers (2)

user3344003
user3344003

Reputation: 21637

The operating system stores the attributes of the file on the disk. The actual disk structure depends upon the operating system.

Is there a folder with all files names and dates?

The Windoze disk structure is NTFS. It has a master file table with information about all the files on the disk.

There are effectively two structures that work cooperatively. Directories define the tree structure holding files. The master file table all the files. It is not a folder with all the files but rather an internal data structure. Generally users cannot see the MFT.

If the disk gets hosed, recovery software will go to the master file table. That allows restoring the files but not their location within the directory structure.

Supposing your friend sends you a text file, how do you get the filename (and other file properties) in your computer?

That is something entirely different from the first question. Email messages encode the file name of a attachments. Your mail program uses that name to create local copies of the file.

Upvotes: 0

mightyWOZ
mightyWOZ

Reputation: 8345

Complete description of what you are asking cannot be covered In a single SO answer, if you really want to understand details then I suggest you pick a good operating system book and read file management section.

A very simple and general description is as follows.

At the very basic level the operating system (file system to be specific) will use two types of data structures to store your file.

• Data structure to store information related to file (meta data)

• Date structure to store the actual data of file that you see ( text,image,sound)

In UNIX world the first data structure is called an Inode, it contains information related to file such as owner, permission, time created, time modified, size, pointer to the data blocks that store the actual data of file. Every file has its own Inode which contains data associated with that file. Note that Inode doesn’t contain the actual file data. actual file data is stored in Data blocks.

So in summary for every file you create, operating system will create a data structure which will contain all the related data.

Upvotes: 1

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