23_File System Basics

# File System Basics

A file system can be seen as a way of organizing and storing data on a storage medium like a hard disk, SSD, or a USB stick. It is responsible for controlling how data is stored and retrieved.

## Types of File Systems

There are many types of file systems, including:

- **FAT (File Allocation Table):** Old, but widely compatible. It's limited in file size and partition size.
- **NTFS (New Technology File System):** Modern, robust, and Windows default. It supports large file sizes, encryption, and permissions.
- **ext4 (Fourth Extended Filesystem):** Default for most Linux distributions. It features journaling for reliability and supports large file sizes.

## File System Components

A typical file system has the following components:

- **Superblock:** Contains metadata about the file system like size, block size, empty and filled blocks.
- **Inode Table:** Stores metadata about files (not the content). Each file has an inode containing info like file size, creation time, owner.
- **Data Blocks:** Actual content of files and directories.

## File System Operations

Common operations include `read`, `write`, `open`, `close`, `mkdir`, `rmdir`, `link`, `unlink`, `chmod`, `stat`.

Here is Python code for some operations:

```python
import os

# Create a new directory
os.mkdir("new_directory")

# Write to a file
with open("file.txt", "w") as f:
    f.write("Hello, File System!")

# Read from a file
with open("file.txt", "r") as f:
    print(f.read())

# Remove a file
os.remove("file.txt")

# Remove a directory
os.rmdir("new_directory")
```

## File System Hierarchy

In Unix-like systems, the file system begins at the root (`/`). Key directories include:

- `/bin`: Essential command binaries
- `/etc`: Host-specific system configuration
- `/home`: User home directories
- `/var`: Variable data like logs and databases

In Windows, drives are the root (`C:\`), with standard folders like `Program Files`, `Windows`, `Users`.

Understanding file systems helps you comprehend how your data is organized and managed, giving you insights for efficient and effective data handling.