Basic Terminal Commands

Opening the Terminal

• Press Ctrl + Alt + T in most desktop environments.
• Or search for "Terminal" in the "applications" menu.

Essential Commands

Navigation

• pwd: Print working directory (shows current location)
• ls: List directory contents
  • ls -l: Long listing format
  • ls -a: Show hidden files
  • ls -h: Human-readable file sizes
• cd: Change directory
  • cd /path/to/directory: Absolute path
  • cd relative/path: Relative path
  • cd ..: Go up one directory
  • cd ~: Go to home directory
  • cd -: Go to previous directory

File Operations

• touch filename: Create an empty file
• mkdir directory: Create a directory
  • mkdir -p parent/child: Create nested directories
• cp source destination: Copy files/directories
  • cp -r source destination: Recursive copy for directories
• mv source destination: Move/rename files/directories
• rm filename: Remove files
  • rm -r directory: Remove directories recursively
  • rm -i: Interactive mode (asks for confirmation)

Viewing Files

• cat filename: Display file contents
• less filename: View file with paging (press 'q' to quit)
• head filename: Show first 10 lines
• tail filename: Show last 10 lines
  • tail -f filename: Follow file (real-time updates)

System Information

• whoami: Show current user
• id: Show user and group IDs
• date: Show current date and time
• uptime: Show system uptime
• df -h: Show disk usage
• free -h: Show memory usage

Help and Manual

• command --help: Show help for a command
• man command: Show manual page (press 'q' to quit)

Command Structure

Most commands follow this pattern: command [options] [arguments]

Examples: - ls -la /home/user - mkdir -p projects/rails_app

Tab Completion

Use the Tab key for auto-completion of commands, file names, and paths.

Command History

• history: Show command history
• Ctrl + R: Search command history
• Up/Down arrows: Navigate history

Practice Exercises

1. Navigate to your home directory.
2. List the contents of the current directory.
3. Create a new directory called "practice".
4. Inside "practice", create a file called "hello.txt".
5. Write "Hello, Linux!" to the file using echo "Hello, Linux!" > hello.txt.
6. View the contents of the file.
7. Copy the file to "hello_copy.txt".
8. Remove the original file.

Next, we'll dive deeper into file and directory management.