Lab 1 Setup: Setting Up Your Computer

We encourage you to complete as much of this setup as you can on your own before coming to lab. If you get stuck, come to office hours or lab to get help.

A. Configure Your Computer

Depending on your oeprating system, there are a bunch of things we need to do to set your computer up for 61B.

The precise steps to take depend on your operating system.

Move on to the next section only once you’ve completed the instructions above for your operating system. Advanced users on Windows may also use the new Bash for Windows feature, but we will not be providing official directions. Note that if you use Bash for Windows, you’ll need to install Java twice (once inside Bash for Windows, and once inside Windows itself, following the directions above).

B. Learn to Use the Terminal

If you already know how to open and use a terminal, skip this section.

The terminal is an application that allows you to run all sorts of programs, as well as manipulate files in your own computer. It is a powerful but also dangerous tool, so please be careful with using some of these commands. On UNIX operating systems, the Terminal application will provide you with everything that you need. On Mac OS, for example, you can use Spotlight to search for the Terminal application.

The lab computers run on the UNIX operating system. As such, you can use xterm commands to make changes to your directory and files. Here are some important ones that you may find useful in this course:

There are some other useful tricks when navigating on command line:

C. Test Run

Let’s ensure that everything is working.

  1. First open up your terminal. Check that git is a recognized command by typing the following command:
     git --version
    

    The version number for git should be printed. If you see “git: command not found”, or similar, try opening a new terminal window, restarting your computer, or installing Git again.

  2. In the terminal, check that python is a recognized command:

     python -i
    

    This should start python in the interactive mode. Use quit() to exit. If it doesn’t work, try the command python3 -i instead, opening a new terminal window, restarting your computer, or reinstalling Python. If none of those work, see the Troubleshooting guide under your operating system.

  3. Lastly, let’s check that javac and java are working. Start by running the following commands at your terminal.

     mkdir ~/temp
     cd ~/temp
    
    1. Then, open your operating system’s file explorer in this directory. You can do this from the command line:

      • Mac: open .
      • Windows: explorer .
      • Ubuntu: gnome-open .
      • Linux Mint: xdg-open . or mate .
    2. In this newly opened directory, create a file HelloWorld.java with these contents:

       public class HelloWorld {
           public static void main(String[] args) {
               System.out.println("Hello world!");
           }
       }
      
    3. In your terminal, enter ls (list the files/folders in this directory). You should see HelloWorld.java listed.

    4. Run javac HelloWorld.java. If this produces any output, then something may be wrong with your setup. Try opening a new terminal window or restarting your computer. If that still doesn’t work, see the Troubleshooting section under the directions for your operating system.

    5. Type ls, you should see both HelloWorld.java and a freshly created HelloWorld.class (the javac command created this file).

    6. Run java HelloWorld. It should print out “Hello world!” for you. If it didn’t, something is wrong with your setup!

    7. You’re done! You can also delete the “temp” folder and its contents as you please.

    The screenshot below shows what we’re hoping for when we do steps 4-7. If you see something similar to this, your java setup is complete. hello_world