Command Line Crash Course

The command line is just a way to manually enter text commands in an application called a terminal. Instead of clicking on icons or using a graphical interface, you type commands into the terminal and receive text responses. This can be a powerful way to perform tasks, especially for tasks that don't have a graphical interface.

• To execute a command, type it in the terminal application and press Enter or Return.
• The Tab key can be used for auto-completing file names or commands.
• Command (⌘) (or Ctrl) + C can be used to stop a running command.
• The up and down arrow keys allow you to cycle through your previously used commands.

IMPORTANT: The commands below are specific to MacOS and other Unix-based systems. Commands on Windows differ slightly than Unix-based systems; for a quick Windows-specific command line tutorial, see this one.

The most common commands you'll use are:

1. cat: Displays the content of a file or concatenates multiple files.

   • Example: cat file.txt

2. cd: Changes the current directory.

   • Example: cd Documents to go to the Documents directory.

3. cp: Copies files or directories.

   • Example: cp source.txt destination.txt to copy source.txt to destination.txt.

4. ls: Lists all files and directories in the current directory.

   • Example: ls

5. man: Displays the manual page for other commands.

   • Example: man ls to see the manual for the ls command.

6. mkdir: Creates a new directory.

   • Example: mkdir NewFolder to create a new folder named "NewFolder".

7. mv: Moves or renames files or directories.

   • Example: mv oldname.txt newname.txt to rename a file.

8. pwd: Displays the path of the current working directory.

   • Example: pwd

9. rm: Removes files or directories.

   • Example: rm file.txt to remove a file named "file.txt".

10. touch: Creates a new, empty file.

    • Example: touch newfile.txt