Computer lab hints

[goodwine]

1. Using Xwin32 you are not able to directly start a session with the computer named hardy.london.nd.edu. However, that is by far the fastest machine. To use it, start a session with one of the other hosts and then type
   
   ssh hardy
   
   in a terminal, which should log you into hardy on that terminal only. If you open multiple terminals, you will have to ssh into hardy in each one if you want everything to run on hardy. To make things from hardy display on the screen, you have to tell it where to send stuff. To do this types
   
   setenv DISPLAY xxx.xxx.xxx.xxx:0
   
   where xxx.xxx.xxx.xxx is the IP address of the PC you are logged onto. There are several ways to find that number, but one way is to right click on the Xwin32 icon and select "XConfig". Under the "display" tab the top number listed under "Available IP addresses" is the one you want to use. It will be something like 195.195.218.xxx where xxx is different for every computer in the lab. (Don't forget the :0 (that's a colon followed by a zero) after the IP address).
   
   The above display command will make xemacs, matlab and anything else you start in the terminal display on the local computer.
   
   This is probably the easiest and best way to make things faster; however, if every single person does it at the same time, it may get slow.
2. Another reasonable setup to speed things up when using a PC is to use the following combination:
   1. Use Xwin32 and run xemacs, gcc and a.out on a session on a Sun.
   2. Run matlab locally on the PC.
   3. Use FSecure fsftp to tranfer files from the Sun to the PC (and back, if necessary). Every time you run your C program you will have to transfer the file if you want to plot the output.
   The only non-obvious thing may be fsftp. If there isn't a shorcut on the desktop, go to "My Computer" -> "C" -> "Program Files" -> "OIT_LICENSED" -> "F-Secure" -> "Ssh" -> "Program" -> "Fsftp" and right click to "Send to" the desktop to make a shortcut.
   
   Launch fsftp (if it's the first time, it may ask you to move the mouse around in a window to generate a random number for encryption purposes). Click on "Commands" -> "Connect" and enter the hostname (use either the Sun computer you are logged onto in Xwin32 or hardy.london.nd.edu). The files on the right are the ones on the Sun filesystem and the ones on the left are on the local computer. To copy them, just drag the file (or even whole folders) from the right side to the appropriate place on the left side.
   
   In matlab type "pwd" to get the current working directory. That's the directory in which matlab will look first if when you type "load <filename>.d". I'm sure there is a way to configure matlab to look elsewhere as well, but will leave that to you.
3. Another way to make things a bit faster will be to log on directly to one of the Suns in the lab. They should be faster than Xwin32 since there isn't the overhead of the interface between Windows and Unix.
4. To print from a unix machine, add the following line to the end of the file called .login that is in your home directory:
   
   setenv PRINTER hp-107
   
   Then any printing from a unix machine will, by default go to the printer in the engineering lab.
   
   To print a text file (like a C program) just do
   
   lpr <filename>
   
   and it should print. Also if you are running any programs on the unix machine like matlab, emacs or netscape, choosing print from the menu should send it to the right printer too.
   
   (Note: the file .login is read when you first log in, so immediately after you modify it you need to either log off and back on, or type "source .login" which will re-read it).
5. To see who and how many people are logged onto a given Sun machine, type either "w" or "who" in a terminal. Doing that should let you find a machine that is relatively unburdened. Keep in mind that hardy can handle a lot more than the others, so even with several people on hardy, it still may be faster than any of the other Suns with no one else logged in.
6. Here is a list of the computers you can use to start sessions:
   
   ada.london.nd.edu
   babbage.london.nd.edu
   faraday.london.nd.edu
   russell.london.nd.edu
   turing.london.nd.edu
   watt.london.nd.edu
   whitehead.london.nd.edu
7. Once you master the skill of ssh'ing around to a bunch of different computers, it's sometimes easy to lose track of which computer a terminal is actually on. The command "hostname" prints the name of the host for a given terminal.