How to Connect to SSCC with Mac OS X

1. Find and Start X11 for MacOS X
2. Customize X11 for MacOS X
3. Log in using X11 for MacOS X
4. Emulating a UNIX Mouse
5. Using Clipboards for Copy and Paste
6. Off-Campus Connections Must First Use VPN
7. Graphical Programs
8. Transferring Files with sftp
9. Transferring Files with fugu

Find and Start X11 for MacOS X

Look for the X11 application, which is found in Applications/Utilities. If it is not installed, get it from your Install DVD as an optional installation.

Drag the X11 application to the Dock to make it easier to launch.

Start X11. A small xterm window will appear, with a command prompt.

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Customize X11 for MacOS X

You can customize the size of the xterm window to make it larger. Choose Applications, Customize. I set up Terminal with the shortcut n to use the command

 xterm -geometry 110x59

That way, I have 110 columns and 59 rows when the xterm window opens.

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Login Using X11 for MacOS X

• Make sure you are connected and authenticated to the NU campus network. If you are off-campus, connect with Cisco VPN (see below).
• Type an ssh command in the xterm window, choosing either to connect to hardin.it.northwestern.edu or seldon.it.northwestern.edu. Substitute your own NetID in place of "NetID" in these commands:

     ssh -Y NetID@hardin.it.northwestern.edu

  or

     ssh -Y NetID@seldon.it.northwestern.edu

• You will be asked for your password. Type your NU NetID password.
• Login messages will appear, followed by the standard Linux command prompt.
• Test your connection: type xclock& and an analog clock will appear in a separate X window.
• To logout, type "logout" and press <return>.
• You can use the arrow keys to repeat and edit your ssh command the next time you open an xterm window.

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Emulating a UNIX Mouse

If you are on a Mac that has a one- or two-button mouse instead of a standard UNIX three-button mouse, you will want to turn on three-button mouse emulation. UNIX X11 applications make extensive use of the middle and right mouse buttons.

To turn this option on, choose the X11 menu, then Preferences. Choose the Input tab, and make sure that Emulate three button mouse is checked. 

Now you can access the middle button of the mouse by holding down the option key on the keyboard and clicking the left or only button on your mouse.

You can access the right button of the mouse by holding down the command key and clicking the mouse button.

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Using Clipboards for Copy and Paste

Copy a block of text into the X11 clipboard by highlighting it with the mouse. In most X11 applications, the text is automatically entered into the clipboard. Some applications may have a Copy button under the Edit menu.

To paste, use the middle (option-left) mouse button. Some X11 applications will have a Paste button in their Edit menu.

The interaction between OS X and X11 applications is separated. If an object is copied from a regular OS X application, it is automatically entered into both OS X and X11 clipboards. However, if an object is copied from within an X11 application, it is only entered into the X11 clipboard. The contents of the X11 clipboard can be placed into the OS X clipboard only by selecting Copy from the Edit menu for X11.

• To copy between two OS X applications, just use the Copy and Paste items from the Edit menu in the menubars of the OS X applications.
• To copy between two X11 applications, highlight text in one application, then middle (option-left) click into the other application.
• To copy from an OS X application into an X11 application, use the Copy button in the OS X application, and middle (option-left) click into the X11 application.
• To copy from an X11 application into an OS X application, highlight the text in the X11 application, use the Edit, Copy button from the X11 titlebar, then use the Edit, Paste button in the OS X application.

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Off-Campus Connections Must First Use VPN

If you are connecting to the SSCC from off campus, you must first establish a Virtual Private Network (VPN) connection to the campus network before you open a connection with SSH. Establishing a VPN connection authenticates you to the NU network, and adds a level of trust and security to your connection.

See Set Up VPN for Macintosh for detailed instructions explaining how to configure and use the VPN Client software.

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Graphical Programs

Graphical access to the interactive computers is useful for tasks that are not computationally-intensive, taking hours of time to execute.

Graphical programs started using X11 run on the interactive computers, not on the compute nodes, so please do not perform long calculations with them.

Remember to close your X11 session when you are done.

Graphical programs are typically run in the background, to free your command line for further work. Follow the command for a graphical program with an ampersand (&) — for example, xstata & — to run xstata in the background in a separate window.

Here are some of the programs with graphical interfaces you might want to use:

Editors — emacs, gvim, lyx and nedit

Document Viewers — acroread, gv, lyx, firefox and xdvi

Graphics Tools — gimp, xfig

PBS Pro Utilities — xpbs, xpbsmon

TeX Utilities — lyx, xdvi

Statistical Applications — matlab, R, sas, Splus, xstata

Utilities — gftp, xclock, xterm

acroread — Acrobat reader for viewing PDF files

emacs — GNU project Emacs editor

firefox— a Web browser for X11 derived from Netscape Communicator

gftp — graphical ftp/sftp client for downloading files from other servers directly to the cluster

gimp — an image manipulation and paint program

gv — a PostScript and PDF viewer

gvim —Vi IMproved, a programmer's text editor

lyx — a document preparation system

matlab — a computational, visualization and programming environment (run with the command matlab -jvm -desktop)

nedit — windows-like text editor for creating and editing your programs and shell scripts

R — a language for data analysis and graphics

sas —an integrated applications system for data access, management, analysis and presentation

Splus — an interactive environment for data analysis and graphics (run with the command Splus -w)

xclock — display an analog or digital clock in an X window

xdvi — DVI previewer for the X window system

xfig — Facility for Interactive Generation of figures under X windows

xpbs — graphical front end to PBS commands to manage batch jobs

xpbsmon — monitor execution hosts under PBS

xstata — Stata with the graphical desktop

xterm — terminal emulator for X windows

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Transferring Files with sftp

You can use the command-line secure shell file transfer program named sftp to transfer files between your Mac and the SSCC.

I usually work from my Mac Desktop, so the first thing I do at the X11 command prompt is change my working directory to the Desktop:

macnelly:~ bef$ cd Desktop

Then connect to seldon:

macnelly:~/Desktop bef$ sftp bef@seldon.it.northwestern.edu
Connecting to seldon.it.northwestern.edu...
bef@seldon.it.northwestern.edu's password:

Change my working directory on seldon to Workshop:

I can retrieve a file with get (transfer from seldon to my Mac):

sftp> get PBS4
Fetching /sscc/home/b/bef/Workshop/PBS4 to PBS4
/sscc/home/b/bef/Workshop/PBS4 100% 725 0.7KB/s 00:00   
sftp>

I can send a file from my Mac to seldon with put:

sftp> put PBS4
Uploading PBS4 to /sscc/home/b/bef/Workshop/PBS4
PBS4 100% 725 0.7KB/s 00:00   
sftp> quit
macnelly:~/Desktop bef$

Of course, quit gets me out of the sftp session.

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Transferring Files with fugu

Fugu is a graphical program that runs on your Mac that functions as a Secure File Transfer application. Fugu was developed by the University of Michigan Research Systems Unix Group. Get Fugu from http://rsug.itd.umich.edu/software/fugu/.