[Day 1] 3. File Management

File Management in an Operating System:

What is a File?

A file is essentially a collection of data stored in a system. When viewed from the OS's perspective, a file consists of:

• Data: The actual content within the file.
• Metadata: Information about the file itself.

Metadata (Information about a File)

The metadata includes details such as:

1. File Name/Path: The name or location of the file in the file system.
2. File Size: The total size of the file in bytes.
3. Timestamps:
   • Created: When the file was created.
   • Last Accessed: When the file was last read or accessed.
   • Last Modified: When the file's content was last changed.
4. Permissions:
   • Access rights granted to different categories:
     • User/Owner: The file's creator or owner.
     • Group: The group the file belongs to.
     • Others: Users who aren't part of the owner or group.
   • Actions that can be performed:
     • Read: View the file’s content.
     • Write: Modify or change the file.
     • Execute: Run the file (for executable or scripts).
5. File Type: Defines whether the file is a text file, binary file, directory, etc.
6. Owner/User: The user who owns the file.
7. Group: The group that has certain access permissions to the file.
8. Link Count: The number of hard links to the file (increased when shortcuts or hard links are created).
9. Data Block Information: Information about how and where the file’s data is stored on the disk. and many more.