===== Help with stu.cs.jmu.edu =====
"stu" is a server running Linux that is available to all students in the JMU
Computer Science Department.

==== Logging in to stu ====
You can login to "stu" using an SSH client (and the host name   ''%%stu.cs.jmu.edu%%''). All modern operating systems should come with command-line SSH client (usually named ''%%ssh%%''). Windows 10 users may need to install the client [[https://www.howtogeek.com/336775/how-to-enable-and-use-windows-10s-built-in-ssh-commands/|manually]], depending on version and edition. GUI SSH clients are also available, but add little.

To log in, type the following in a terminal/cmd window, replacing <eid> with your JMU username.

    ssh <eid>@stu.cs.jmu.edu

Enter your password when prompted. Nothing will appear on the screen so type carefully!

=== Keypairs ===
You can avoid the need to authenticate yourself (with your eID and password) each time you login [[ student:utilities:start:keypairs | using a public/private key pair]]. This is particularly useful when using another protocol (e.g., Subversion or Git) on top of SSH.

=== Timeout ===
Add the following to your ~/.ssh/config file if you are getting disconnected from stu due to an idle timeout:
<code>
Host *
    TCPKeepAlive yes
    ServerAliveInterval 15
</code>

==== Accessing Lab Computers====
To log into a specific lab computer you first login to stu as normal and then ssh to a lab machine by hostname. The hostnames are based on the room and computer number and take the form "L[room_number][computer_number].cs.jmu.edu".

^ Room         ^ Hostname Range          ^
| ISAT/CS 248 | L248{01..32}.cs.jmu.edu |
| ISAT/CS 250 | L250{01..31}.cs.jmu.edu |
| ENGEO 2204 | L2204{01..32}.cs.jmu.edu  |

This can be simplified by using the ''-J'' option to ssh. For example, the following command would jump through stu to reach a lab computer in ISAT/CS 250.

    ssh -J <eid>@stu.cs.jmu.edu <eid>@l25005.cs.jmu.edu

You can do this transparently by adding the following to your ~/.ssh/config:

    Match !host stu.cs.jmu.edu host *.cs.jmu.edu !exec "nc -z -w 1 %h %p"
        ProxyJump stu.cs.jmu.edu

This uses netcat to determine if you can connect directly to the host and if not, for all .cs.jmu.edu hosts other than stu, jump through stu. Connecting to a lab machine with this configuration is the same from on or off campus: ''ssh l25005.cs.jmu.edu''.

Setting up keypairs is highly recommended if you're doing this regularly to avoid multiple password prompts.

==== Transferring Files to and From stu ====
You can transfer files to "stu" using an SCP client (and the host name  ''%%stu.cs.jmu.edu%%''). Modern operating systems include a command-line scp client named ''scp''. See [[http://www.hypexr.org/linux_scp_help.php|this article]] for some usage examples. There are also GUI clients available that work like a file explorer. Options include [[ https://filezilla-project.org/| FileZilla]], [[https://winscp.net/eng/index.php|WinSCP]] and [[https://cyberduck.io/|Cyberduck]]. Both SCP and SFTP use port 22 (see more detailed instructions on [[student:stu:filezilla|Transferring Files from Your JMU CS Account with FileZilla]].


If you want a more seamless experience or the ability to edit files on "stu" using a local editor like Eclipse or VS Code, you can [[student:utilities:sshfs|mount your home folder locally]]. 

==== Using stu as an HTTP Server ====


You (should) have a directory named ''%%www%%'' in your home directory.   Any file that you put in that directory will be available to the   public as a "web page" (i.e., it will be served in response to an HTTP GET   request) from the server ''%%w3stu.cs.jmu.edu%%'' under your   e-ID.


For example, if Prof. Fakename (i.e., ''%%fakenazx%%'')   put a file named ''%%test.html%%'' in her ''%%www%%''   directory it would be accessible to the public using the URL   as ''%%w3stu.cs.jmu.edu/fakenazx/test.html%%''.

Of course, the HTTP server must have permission to read the file. So,   the file must be world-readable.