CSE15L Tutorial

By Angelia

Hello everyone, let’s get starting with CSE15L today!

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Part 1 Install Visual Studio Code

• Go to Visual Studio Code website.
• Follow the instruction to download and install the application on your computer.
• important: There are versions for all the major operating systems, like OSX (for Macs) and Windows (for PCs). Please make sure the version you download matching your computer.
• After installing, you should be able to open te window like this(there might be a little different on its appearance, dipending on your system and setting.)

Part 2 Connect to a Remote Host

• Follow the instruction How-to-Reset-your-Password.pdf to activate your CSE15L server account.
• For windows users, install OpenSSH on your computer before starting.
• Then start to connect to a remote host:
  1. Open a terminal in VSCode.
  2. Do the command like this:

$ ssh cs15lsp22app@ieng6.ucsd.edu replace “app” with your special-course account.

1. You will probably recieve a message like this:

⤇ ssh cs15lsp22app@ieng6.ucsd.edu

The authenticity of host 'ieng6.ucsd.edu (128.54.70.227)' can't be established.

RSA key fingerprint is 
SHA256:ksruYwhnYH+sySHnHAtLUHngrPEyZTDl/1x99wUQcec.

Are you sure you want to continue connecting (yes/no/[fingerprint])?

Type yes and press enter.

1. Put in your password as required. You will have a view like this:

Part 3 Run Some Commands

Now you are connecting with the remote host if you have finished every step.

Let’s try some commands:

• $ cd (change direction)

• $ ls -lat (list all files)

• $ ls <directory> where <directory> is /home/linux/ieng6/cs15lsp22/cs15lsp22abc, where the abc is one of the other group members’ username.

• $ cp (copy)

• $ cat (create or view a file)

• Ctrl+D (exit)

Part 4 Moving Files Over SSH with scp

• scp: copy a file (or many files!) from your computer to a remote computer

• Create a file called WhereAmI.java on your computer.

Content of WhereAmI.java:

class WhereAmI {
  public static void main(String[] args) {
    System.out.println(System.getProperty("os.name"));
    System.out.println(System.getProperty("user.name"));
    System.out.println(System.getProperty("user.home"));
    System.out.println(System.getProperty("user.dir"));
  }
}

• $ scp WhereAmI.java cs15lsp22app@ieng6.ucsd.edu:~/

Operate this step with the special-course account which you are logging.

• Do javac WhereAmI.java and java WhereAmI to run the file and then you will get this: The result of WhereAmI.java shows that the location of the file is the remote computer you are logging.

Part 5 Setting an SSH Key

• Run the followinng commands in your terminal after logging out of the remote:

# on client (your computer) (or log out the remote)

$ ssh-keygen

Generating public/private rsa key pair.

Enter file in which to save the key (/Users/angeliaz/.ssh/id_rsa): /Users/angeliaz/.ssh/id_rsa (`<user-name>`should be the name of your computer).

Enter passphrase (empty for no passphrase): (Do not type anything and press `enter` directly)

Enter same passphrase again: (Press `enter` directly)

Your identification has been saved in /Users/angeliaz/.ssh/id_rsa

Your public key has been saved in /Users/angeliaz/.ssh/id_rsa.pub

The key fingerprint is:

SHA256:2mcfE+QlQ4a4hcop7W51vVTnRWA/pPKuAPMYTTzJXXQ angeliaz@Angelias-Mini.lan

The key’s randomart image is:

+---[RSA 3072]----+

|         o .+ooE |

|        = =o..+..|

|     o o O o+..o.|

|    . = + .oo+. +|

|      o S = *.B. |

|       = = O.*.*+|

|     ..o.+o.oo   |

|           +.+.o |

|             ..  |

+----[SHA256]-----+

You may have a picture like this:

• Now we need to copy the public key to .ssh directory of your user account on the server.

$ ssh cs15lsp22app@ieng6.ucsd.edu (log in you course account)

<Enter Password> (now on server)

$ mkdir .ssh (mkdir: make directory)

$ <logout> (back on client)

$ scp /Users/angeliaz/.ssh/id_rsa.pub cs15lsp22app@ieng6.ucsd.edu:~/.ssh/authorized_keys

Part 6 Optimizing Remote Running

Now log out the remote server and do:

• $ cp WhereAmI.java OtherMain.java; javac OtherMain.java; java WhereAmI

• $ ssh cs15lsp22app@ieng6.ucsd.edu "ls"

• $ scp WhereAmI.java cs15lsp22app@ieng6.ucsd.edu:~/

• $ ssh cs15(sp22app@ieng6.ucsd.edu "javac WhereAmI.java; iava WhereAmI"

Here’s some examples when you run the commands above. Now you can run several commands in one line, and operate files on the remote server without log-in and putting in password.

Save you time!

-The End-

-Thank you!-

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