File Operations in Operating Systems: Managing Files and Data

Explore the fundamental file operations provided by operating systems for managing data stored on storage devices. This guide explains how file systems handle file creation, deletion, reading, writing, and other operations, and their role in providing a structured and efficient way to interact with persistent data.

File Operations in Operating Systems

Understanding File Operations

A file is a structured collection of data stored persistently on a storage device (like a hard drive). The operating system (OS) provides a set of operations or functions that allow users and applications to interact with files. These file operations are initiated using system calls that pass requests to the file system. The file system then performs the requested actions on the underlying storage.

Common File Operations

  1. Create: Creates a new, empty file. The OS allocates disk space and adds an entry for the new file into the appropriate directory. The file type is determined by the application making the request.
  2. Open: Opens an existing file, making it accessible for reading or writing. The OS finds the file based on its name and checks permissions. This operation also creates internal data structures (file descriptors) needed for the OS to manage the file.
  3. Write: Writes data to the file. The system call specifies the file, the data to be written, and the length of data. The file's size is increased, and the file pointer is updated.
  4. Read: Reads data from the file. The OS uses a file pointer to track the read position within the file.
  5. Seek/Reposition: Moves the file pointer to a specific location within the file (for random access files).
  6. Delete: Removes the file. The OS deallocates disk space and removes the directory entry for the file.
  7. Truncate: Removes data from the end of the file, reducing its size. File attributes are retained.
  8. Close: Closes the file. The OS releases resources associated with the open file (file descriptors) and updates the file's metadata to reflect changes.
  9. Append: Adds data to the end of an existing file, increasing its size.
  10. Rename: Changes the file's name.