Linux Directory Structure Overview

The Linux file system follows a hierarchical directory structure with standardized locations for different types of files and system components.

Key System Directories

• /bin: Contains essential binary executables and system commands
• /boot: Stores boot loader files and kernel images
• /dev: Device files representing hardware components
• /etc: System configuration files and scripts
• /home: User home directories with individual workspace
• /lib: Shared library files required by system binaries
• /media: Mount point for removable media devices
• /mnt: Temporary mount point for file systems
• /opt: Optional software packages and applications
• /proc 2. /root: Home directory for the root user 3. /sbin: System administration binaries 4. /tmp: Temporary files cleared on reboot 5. /usr: User applications and read-only data 6. /var: Variable data including logs and spool files

File and Directory Operations

Navigation Commands

ls - List directory contents:

ls -la    # Show all files including hidden with details
ls -d */  # Display only directories

cd - Change directory:

cd /absolute/path    # Absolute path navigation
cd relative/path     # Relative path navigation  
cd ~                 # Return to home directory
cd ..                # Move to parent directory

pwd - Print working directory:

pwd -P    # Show physical path without symbolic links

Directory Management

mkdir - Create directories:

mkdir project_folder
mkdir -p nested/folder/structure    # Create parent directories
mkdir -m 755 secure_dir            # Set specific permissions

rmdir - Remove empty directories:

rmdir empty_folder
rmdir -p level1/level2/level3      # Remove directory hierarchy

File Operations

cp - Copy files and directories:

cp source.txt destination.txt
cp -r source_dir/ target_dir/      # Recursive directory copy
cp -a original backup              # Preserve all attributes

mv - Move or rename files:

mv oldname.txt newname.txt
mv file.txt target_directory/
mv -i existing newfile            # Interactive overwrite

rm - Remove files and directories:

rm unwanted_file.txt
rm -r directory_to_delete         # Recursive removal
rm -f protected_file              # Force removal

Practical File Management Exercises

Directory Creation and Deletion

# Create personal workspace
mkdir /home/datawhale/username
cd /home/datawhale/username

# Create nested directory structure
mkdir datawhale_project
cd datawhale_project

# Create and remove test file
touch sample_data.txt
rm sample_data.txt

# Clean up directories
cd ..
rm -r datawhale_project
rm -r username

File Download and Inspection

# Create project structure
mkdir -p /home/datawhale/user_workspace/project_data

# Download dataset
wget -P /home/datawhale/user_workspace/project_data https://mirror.coggle.club/dataset/affairs.txt

# Examine file contents
head affairs.txt        # First 10 lines
tail affairs.txt        # Last 10 lines  
cat affairs.txt         # Entire file content

Python Environment Setup

# Launch Python environment
ipython

# Import and examine data
import pandas as pd
dataset = pd.read_csv('affairs.txt')
print(dataset.head())

Text Editing with Nano and Vim

Nano Editor

# Create Python script with Nano
nano hello_world.py

# Add script content:
#!/usr/bin/env python3
print('Hello World!')

# Save: Ctrl+O, Exit: Ctrl+X

Vim Editor

# Create script with Vim
vim greeting_script.py

# Insert mode: press 'i'
# Add content:
#!/usr/bin/env python3
print('Hello World!')

# Save and exit: Esc, :wq

Make Script Executable

chmod +x hello_world.py
./hello_world.py