Deliverable	Due Date
Base Installation (nothing to submit)	Monday, February 5th at 1:00PM EST
Intro to Linux Gradescope Submission	Wednesday, February 14th at 1:00PM EST
Intro to Git Gradescope Submission	Wednesday, February 14th at 1:00PM EST

Intro to Linux

Linux is an essential part of the class, so it's important to get some experience with this before working with the robots. Although you're encouraged to collaborate with others if you are stuck, the lab should be completed individually so you can get practice with skills that will be essential later on in the course when you are in teams. If you have general questions, please post on Piazza so other students can benefit from the answer. If you have a question about your individual submission, please make a private post. Make sure you're using a Debian terminal if you're testing the commands. Instructions for setting up the course software is here. Alternatively, you can use your Athena terminal to test commands by typing ssh <kerberos>@athena.dialup.mit.edu in your terminal, substituting <kerberos> for your own kerberos username. Most of the commands below should work, although a few of them may not.

Gradescope Submission

In order to get credit for this assignment, you will submit a .zip file to Gradescope under Lab 1A: Intro To Linux. The format of the file will be specified in Question 4. Your submission will not get graded properly if you don't put it in the right format.

References

If you don't have previous experience with Linux, we recommend that you read the following tutorials by the Software Carpentry Foundation before starting on the exercises. Otherwise, you can just use the resources as you need.

1. Setup
2. Introducing the Shell
3. Navigating files and directories
4. Working with files and directories
5. Pipes and filters
6. Finding things

There are also many Linux cheatsheets online such as the ones here and here.

Additionally, there is a universally available reference bundled with almost every Unix system called "man pages" or manual pages. By typing man <command> in the terminal, where <command> is the command you want to learn about, you can see comprehensive documentation about the command. Many commands also display useful information when called with the help option by running <command> -h or <command> --help.

Instructions

1. Clone this repository by typing git clone https://github.com/mit-rss/intro_to_linux.git into your terminal. Please make sure you do this in ~/racecar_ws/src if you are using the Docker image.
2. Place your answers to 1-3 in linux_exercise.txt. Every command should go between the #####<question_number>####### and #####End of Question####### lines
3. During this class, you will need to be familiar with at least one terminal-based text editor like vim, nano, emacs. We recommend getting some practice with a terminal-based text editor when you're editing linux_exercise.txt.
4. Run sanity_checker.py to double check that your answers are correctly formatted
5. Provide a single command for each of the following questions. If multiple answers are possible, choose the shortest answer. All of your commands should work regardless of your current working directory. Hint
6. Continue onto question 4 to find out how to submit your answers. Unlike problems 1-3, this exerise relies on using multiple commands to reformat your directory. So, feel free to pipe many commands together or complete file manipulations in consecutive lines as needed. The commands you use to complete this problem will not be added to the linux_exercise.txt file!

Question 1: Navigating your Home

The first thing you need to learn in the command-line is how to navigate the filesystem and view the contents of directories and files.

1a. Navigate to your home directory
1b. Navigate to your root directory
1c. Navigate to the parent directory of your current directory
1d. List all the files/directories in your home directory, including hidden ones, in long listing format
1e. Print your current working directory

Question 2: Installing and Controlling Programs

One of the awesome features of UNIX-based operating systems is how simple it is to install programs through the terminal. For this question, use apt.

2a. Install a program called inxi
2b. Show output control options for inxi in the terminal to see what it does
2c. Use inxi to show information about your hardware disk info.
2d. Uninstall inxi
2e. Update the list of available Debian packages 2f. Upgrade all existing packages

Question 3: ssh

Another cool feature that you will be using often in this class is SSH (Secure SHell), which enables you to access the terminals of other Linux-powered remote devices or systems as long as you have access credentials. This is how you will access the racecars.

3a. Log into a remote shell with the address athena.dialup.mit.edu and your kerberos as the username. This will give you secure remote access to a shell running on an Athena machine.
3b. Logged into your Athena account, download the contents from https://tinyurl.com/ya67uga4 into a file named pic.png in your Athena home directory.
3c. Exit the ssh session
3d. Using the scp command from your local terminal, move the photo you just downloaded from your Athena account, ~/pic.png, onto your native machine into the folder ~/Pictures on your machine. This is useful for transferring files between your computer and the Racecar.

Question 4: Practice

Now that you're familiar with the basics of the command line, complete the following exercise in order to get credit for this assignment. In this exercise, you will be reorganizing the .txt files found in the lab1/ directory. In addition to the commands introduced in questions 1-3, you might find grep, |, >, >>, xargs, awk, sed, mkdir, rm, wc, cat, cut, zip, sort, for, etc useful. We encourage you to work incrementally, use man pages and the internet as a resource, and write down commands that are helpful as you go.

Please perform the following modifications to the lab1/ directory:

1. Any file with the extension .txt that does not contain exactly 10 lines is corrupted and should be deleted from the whole directory. The names of the files that are deleted should be written in a file called deleted_files.txt with 1 filename per line in ascending numerical order (not alphabetical order).
2. Out of the remaining .txt files with 10 lines, the ones that contain the string "IMPORTANT" should be placed in a new directory named important/. The rest of the .txt files should be placed in another new directory named unimportant/.
3. After reorganizing all the .txt files, add the file named linux_exercise.txt that contains your answers to questions 1-3 into the lab1/ directory.
4. Zip the folder into a file called lab1.zip

As a summary, the final zipped folder should contain the following:

• linux_exercise.txt
• deleted_files.txt
• important/
• unimportant/

Remember: The shell and filesystem are case sensitive (unlike on Windows!). Therefore, we expect correct use of upper and lower case in the commands and files in your submission.

Notes: Make sure you are using the provided VM or an Debian or Ubuntu machine when doing question 4 or weird things might happen when it's graded.

Question 5: alias and .bashrc

Add an alias to the end of your ~/.bashrc file that runs ls -alF when you type ll. The .bashrc file is executed every time you start a new shell, so this allows you to create shortcuts for longer commands. You should test your command by typing source ~/.bashrc and typing ll. You do not need to submit anything for this question.