Terminal Commands

Learning Your Ship's Language

Before you can navigate through space, you need to communicate with your spacecraft's computer. The command line is your direct interface to the ship's systems—no graphical buttons, just pure, efficient commands.

Essential Navigation Commands

Where Am I? (pwd)

The pwd command (print working directory) tells you your current location in the file system:

pwd

Output might look like:

/home/astronaut/projects

What's Here? (ls)

The ls command lists files and directories in your current location:

ls

For more details, add flags:

ls -la

This shows hidden files (-a) with detailed information (-l).

Windows users: Use dir in Command Prompt, or ls in Git Bash/PowerShell.

Change Location (cd)

The cd command (change directory) moves you through the file system:

cd projects          # Move into 'projects' directory
cd ..                # Move up one level
cd ~                 # Go to home directory
cd /path/to/dir      # Go to specific path

File System Manipulation

Create Directory (mkdir)

Create a new directory (folder):

mkdir my-mission
mkdir -p deep/nested/directories  # Create parent directories too

Create File (touch)

Create an empty file:

touch mission-log.txt

Windows Command Prompt users: Use echo. > filename.txt or type nul > filename.txt

Remove Files (rm)

Delete files (be careful—this is permanent!):

rm old-file.txt
rm -r directory/     # Remove directory and contents
rm -rf directory/    # Force remove (very dangerous!)

Windows Command Prompt: Use del for files, rmdir for directories.

Copy Files (cp)

cp source.txt destination.txt
cp -r source-dir/ destination-dir/  # Copy directories

Windows Command Prompt: Use copy for files, xcopy for directories.

Move/Rename (mv)

mv old-name.txt new-name.txt  # Rename
mv file.txt other-dir/        # Move file

Windows Command Prompt: Use move or ren (rename).

Viewing File Contents

Display File (cat)

Show entire file contents:

cat file.txt

Windows Command Prompt: Use type file.txt

View Large Files (less)

For large files, use less for scrollable viewing:

less large-log.txt

Press q to quit, Space to scroll, / to search.

Useful Shortcuts and Tricks

Tab Completion

Press Tab to auto-complete file and directory names. This saves time and prevents typos.

Command History

• Press ↑ (up arrow) to cycle through previous commands
• Type history to see all recent commands
• Press Ctrl+R to search command history

Clear Screen

clear        # macOS/Linux
cls          # Windows Command Prompt

Paths: Absolute vs Relative

Absolute Path

Starts from the root directory:

/home/astronaut/projects/mission

Relative Path

Starts from your current location:

./current-directory
../parent-directory
../../grandparent-directory

Combining Commands

Use pipes (|) to chain commands:

ls -la | grep ".txt"     # List all .txt files
cat file.txt | wc -l     # Count lines in file

Output Redirection

Redirect command output to files:

ls -la > file-list.txt          # Write to file (overwrite)
echo "New log entry" >> log.txt  # Append to file

Getting Unstuck

• Stuck in a command? Press Ctrl+C to cancel
• Terminal frozen? Press Ctrl+Z to suspend, or close and reopen
• Made a mistake? Most terminal commands can't be undone—be careful with rm!

Windows-Specific Notes

Windows has different commands in traditional Command Prompt:

Recommendation: Windows users should use Git Bash or PowerShell for Unix-like commands.

Ready for Configuration

You now know the basic commands to navigate your file system. These work alongside Git—you'll use them to move between projects, create directories, and manage files.

Next, we'll configure Git with your identity so your commits are properly attributed to you.