Filesystem Navigation and Manipulation

# List directory contents
ls

# Change current working directory
cd ~/Desktop      # Move to Desktop
cd ..             # Go up one level
cd /              # Switch to root directory

# Print absolute path of the current directory
pwd

# Create a new directory
mkdir project_alpha

# Generate an empty file or update its timestamp
touch index.html

# Remove files or directories permanently (bypasses Trash)
rm obsolete_log.txt
rm -r legacy_code  # Delete directory recursively
rm -rf cache_build # Force recursive deletion

# Duplicate files and directories
cp draft.md final.md
cp -r src/ backup/ # Copy directory recursively

Terminal commands typically consist of three components: Options (prefixed by -), Arguments (targets for the command), and Extras (additional data). Options can often be combined, such as ps -e -f being equivalent to ps -ef. Arguments specify the target, e.g., ls /var/log.

File Inspection and Editing

# Output entire file content
cat configuration.yaml

# View file content with scrolling
less large_log.txt

# Edit files using terminal-based text editors
nano todo.txt
vim script.sh

System Diagnostics

# Display current date and time
date

# Output a calendar
cal

# Check disk space usage
df -h

# Monitor active processes and resource consumption
top

Network Utilities

# Verify network connectivity to a remote host
ping google.com

# Inspect network interface configurations (en0 is typical for macOS Wi-Fi)
ifconfig en0

# Fetch data from a URL
curl https://api.example.com/data

Archiving and Compression

# Archive files
tar -czf archive.tar.gz directory_name/

# Compress or decompress files
gzip large_file.txt
gunzip large_file.txt.gz

Access Control and Privileges

# Execute commands with elevated privileges
sudo apt update

# Identify the currently logged-in user
whoami

# Transfer file ownership
chown user:group target_file

# Modify file permissions
# u (user), g (group), o (others), a (all)
# r (read), w (write), x (execute)
chmod u=rwx,g=rx,o=r script.sh
chmod -R a+rx /opt/application  # Apply recursively

Process Management

# List currently running processes
ps aux

# Terminate a process by its ID
kill -9 12345

Background Execution

Appending & to a command runs it in the background, freeing up the terminal session.

npm run build &

Aborting Running Commands

Press Control + C in the active terminal window to send an interrupt signal and halt the currently executing process.

Miscellaneous Utilities

# Clear the terminal viewport
clear

# Review previously executed commands
history

# Search for specific text patterns within files
grep "ERROR" /var/log/syslog

# Locate files within a directory hierarchy
find . -name "*.js"

# Print text to the terminal
echo "Deployment complete"

# Compile source code
gcc main.c -o executable_bin

# Run a compiled binary
./executable_bin

# Disable Time Machine local snapshots
sudo tmutil disablelocal

# System power controls
sudo shutdown -h now   # Power off immediately
sudo shutdown -h +30   # Power off in 30 minutes
sudo shutdown -r now   # Reboot immediately

Homebrew Package Management

# Install, remove, or reinstall packages
brew install wget
brew uninstall wget
brew reinstall wget

# Query package information
brew list              # Show installed packages
brew search postgres   # Search for available formulas
brew info wget         # Display package details
brew deps wget --installed --tree # View dependency tree
brew --prefix wget     # Reveal installation path

# Maintain Homebrew
brew update            # Fetch latest version of Homebrew
brew upgrade           # Upgrade all outdated packages
brew cleanup           # Remove stale lock files and old versions

# Manage background services
brew services start redis
brew services stop redis
brew services restart redis
brew services list     # Show status of managed services

# Other operations
brew --version         # Display current Homebrew version
brew link --overwrite node # Overwrite existing files when linking