# Introduction to command line > For readers at home: this chapter is covered in the [Your new friend: Command Line](https://www.youtube.com/watch?v=jvZLWhkzX-8) video. It's exciting, right?! You'll write your first line of code in just a few minutes! :) **Let us introduce you to your first new friend: the command line!** The following steps will show you how to use the black window all hackers use. It might look a bit scary at first but really it's just a prompt waiting for commands from you. > **Note** Please note that throughout this book we use the terms 'directory' and 'folder' interchangeably but they are one and the same thing. ## What is the command line? The window, which is usually called the **command line** or **command-line interface**, is a text-based application for viewing, handling, and manipulating files on your computer. It's much like Windows Explorer or Finder on the Mac, but without the graphical interface. Other names for the command line are: *cmd*, *CLI*, *prompt*, *console* or *terminal*. ## Open the command-line interface To start some experiments we need to open our command-line interface first. ## Prompt You now should see a white or black window that is waiting for your commands. If you're on Mac or Linux, you probably see a `$`, like this: ``` $ ``` On Windows, you probably see a `>`, like this: ``` > ``` Take a look at the Linux section just above now -- you'll see something more like that when you get to PythonAnywhere later in the tutorial. Each command will be prepended by a `$` or `>` and one space, but you should not type it. Your computer will do it for you. :) > Just a small note: in your case there may be something like `C:\Users\ola>` or `Olas-MacBook-Air:~ ola$` before the prompt sign, and this is 100% OK. The part up to and including the `$` or the `>` is called the *command line prompt*, or *prompt* for short. It prompts you to input something there. In the tutorial, when we want you to type in a command, we will include the `$` or `>`, and occasionally more to the left. Ignore the left part and only type in the command, which starts after the prompt. ## Your first command (YAY!) Let's start by typing this command: ``` $ whoami ``` ``` > whoami ``` And then hit `enter`. This is our result: ``` $ whoami olasitarska ``` As you can see, the computer has just printed your username. Neat, huh? :) > Try to type each command; do not copy-paste. You'll remember more this way! ## Basics Each operating system has a slightly different set of commands for the command line, so make sure to follow instructions for your operating system. Let's try this, shall we? ### Current directory It'd be nice to know where are we now, right? Let's see. Type this command and hit `enter`: ``` $ pwd /Users/olasitarska ``` > Note: 'pwd' stands for 'print working directory'. ``` > cd C:\Users\olasitarska ``` > Note: 'cd' stands for 'change directory'. With PowerShell you can use pwd just like on Linux or Mac OS X. You'll probably see something similar on your machine. Once you open the command line you usually start at your user's home directory. *** ### Learn more about a command Many commands you can type at the command prompt have built-in help that you can display and read! For example, to learn more about the current directory command: OS X and Linux have a `man` command, which gives you help on commands. Try `man pwd` and see what it says, or put `man` before other commands to see their help. The output of `man` is normally paged. Use the space bar to move to the next page, and `q` to quit looking at the help. Adding a `/?` suffix to most commands will print the help page. You may need to scroll your command window up to see it all. Try `cd /?`. ### List files and directories So what's in it? It'd be cool to find out. Let's see: ``` $ ls Applications Desktop Downloads Music ... ``` ``` > dir Directory of C:\Users\olasitarska 05/08/2020 07:28 PM Applications 05/08/2020 07:28 PM Desktop 05/08/2020 07:28 PM Downloads 05/08/2020 07:28 PM Music ... ``` > Note: In PowerShell you can also use 'ls' like on Linux and Mac OS X. *** ### Change current directory Now, let's go to our Desktop directory: ``` $ cd Desktop ``` ``` $ cd Desktop ``` Note that the directory name "Desktop" might be translated to the language of your Linux account. If that's the case, you'll need to replace `Desktop` with the translated name; for example, `Schreibtisch` for German. ``` > cd Desktop ``` Check if it's really changed: ``` $ pwd /Users/olasitarska/Desktop ``` ``` > cd C:\Users\olasitarska\Desktop ``` Here it is! > PRO tip: if you type `cd D` and then hit `tab` on your keyboard, the command line will automatically fill in the rest of the name so you can navigate faster. If there is more than one folder starting with "D", hit the `tab` key twice to get a list of options. *** ### Create directory How about creating a practice directory on your desktop? You can do it this way: ``` $ mkdir practice ``` ``` > mkdir practice ``` This little command will create a folder with the name `practice` on your desktop. You can check if it's there by looking on your Desktop or by running a `ls` or `dir` command! Try it. :) > PRO tip: If you don't want to type the same commands over and over, try pressing the `up arrow` and `down arrow` on your keyboard to cycle through recently used commands. *** ### Exercise! A small challenge for you: in your newly created `practice` directory, create a directory called `test`. (Use the `cd` and `mkdir` commands.) #### Solution: ``` $ cd practice $ mkdir test $ ls test ``` ``` > cd practice > mkdir test > dir 05/08/2020 07:28 PM test ``` Congrats! :) *** ### Clean up We don't want to leave a mess, so let's remove everything we did until that point. First, we need to get back to Desktop: ``` $ cd .. ``` ``` > cd .. ``` Using `..` with the `cd` command will change your current directory to the parent directory (that is, the directory that contains your current directory). Check where you are: ``` $ pwd /Users/olasitarska/Desktop ``` ``` > cd C:\Users\olasitarska\Desktop ``` Now time to delete the `practice` directory: > **Attention**: Deleting files using `del`, `rmdir` or `rm` is irrecoverable, meaning *the deleted files will be gone forever*! So be very careful with this command. ``` $ rm -r practice ``` ``` > rmdir /S practice practice, Are you sure ? Y ``` Done! To be sure it's actually deleted, let's check it: ``` $ ls ``` ``` > dir ``` ### Exit That's it for now! You can safely close the command line now. Let's do it the hacker way, alright? :) ``` $ exit ``` \`\`\` > exit \`\`\` Cool, huh? :) ## Summary Here is a summary of some useful commands: | Command (Windows) | Command (Mac OS / Linux) | Description | Example | | ----------------- | ------------------------ | -------------------------- | -------------------------------------------------- | | exit | exit | close the window | **exit** | | cd | cd | change directory | **cd test** | | cd | pwd | show the current directory | **cd** (Windows) or **pwd** (Mac OS / Linux) | | dir | ls | list directories/files | **dir** | | copy | cp | copy file | **copy c:\test\test.txt c:\windows\test.txt** | | move | mv | move file | **move c:\test\test.txt c:\windows\test.txt** | | mkdir | mkdir | create a new directory | **mkdir testdirectory** | | rmdir (or del) | rm | delete a file | **del c:\test\test.txt** | | rmdir /S | rm -r | delete a directory | **rm -r testdirectory** | | \[CMD] /? | man \[CMD] | get help for a command | **cd /?** (Windows) or **man cd** (Mac OS / Linux) | These are just a very few of the commands you can run in your command line, but you're not going to use anything more than that today. If you're curious, [ss64.com](http://ss64.com) contains a complete reference of commands for all operating systems. ## Ready? Let's dive into Python! --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://djangogirls-2.gitbook.io/tutorial/intro_to_command_line.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.