MathLAN: Frequently asked questions

How can I get an account on MathLAN?

If you're a Grinnell College student, faculty member, or staff member, just bring your ID to Science 2418. The manager of MathLAN will set up an account for you and give you the password. The process takes only a couple of minutes.

If you're not a member of the Grinnell College community, you're out of luck, unless you have very good contacts.

Can our student organization have its own account, one that we can all log into and share files?

No, there are no group accounts on MathLAN. However, the manager of MathLAN can set up a file-ownership group for you, so that any member of the group can arrange for files in her own home directory to be readable by other members of the group but not by the world at large. Send him e-mail listing the members of the group you'd like to establish.

I'd like to change the password on my MathLAN account. How should I go about it?

Log in, using your current password. Move the mouse pointer onto the small image of a monitor on the panel at the bottom of the screen. Click the left mouse button once to open up a window in which the gnome-terminal emulator is running. Move the mouse pointer into that window and type the word password. Press the Enter key at the end. You'll be asked to type in your old password once and the new password twice, pressing Enter at the end each time. (Neither password will appear on screen when you type it, so watch your fingers instead of the screen.) If you give your old password correctly and the two versions of your new password match, you'll see an acknowledgement that your password has been changed; otherwise, you'll get an error message, in which case you should try again.

The passwords on MathLAN accounts are reviewed at irregular intervals. You may be asked to change your password again if you select one that can be guessed too easily. Avoid using common words, names, or abbreviations as passwords; try to choose passwords that include digits, punctuation marks, or nonsense syllables.

I deleted a file by mistake. Is there any way to get it back?

Users' home directories are backed up fully five times a year (about January 6, March 21, May 31, August 16, and October 21) and an incremental backup is performed at 4 a.m. every day except Wednesday. If your file existed at the time one of these backups was performed, it can probably be restored. On the other hand, if you created and then deleted the file, or a new version of the file, between backups, it's gone forever.

Some application programs, notably GNU Emacs and DrScheme, create backup files automatically. Check the directory for similarly named files that might be automatic backups.

How can I print a text file?

In a window in which the gnome-terminal terminal emulator is running, type

a2ps filename

(putting the name of your file in place of filename, of course). If you're in the lab or the computer-equipped classroom, this will send the print job to one of the printers in the lab -- which one it goes to depends on which workstation you happen to be using.

The a2ps program has many bells and whistles, which can be activated by means of command-line options. For example, the command

a2ps -2 -r -P pacioli filename

prints two pages on one sheet, in landscape mode (when you read the printout, you'll hold it so that it is wider than it is long), on the printer named pacioli (in Science 2417).

How can I create a subdirectory within my home directory?

In a window in which the gnome-terminal terminal emulator is running, type

cd; mkdir directory-name

(putting the name of the subdirectory you want to create in place of directory-name). The command that actually creates the subdirectory is mkdir; the cd; at the beginning is just to make sure that your current working directory is your home directory.

Alternatively, open up the Nautilus file manager by double-clicking with the left mouse button on the icon of a folder with a house on the front of it, near the upper left corner of your desktop. When its window appears, select Create Folder from the File menu. A new folder icon, labelled untitled folder, will appear in the window. Replace the label with the name that you want the new directory to have.

There's a subdirectory of my home directory that I no longer need. How do I get rid of it?

First, look over the files that are in that subdirectory and move any of them that you want to keep into your home directory or other subdirectories. For instance, if the subdirectory is called delendum and you want to keep a file named precious in that subdirectory, go to a gnome-terminal window and type

cd ~/delendum; mv precious ~

This will move precious into your home directory.

Now that your current working directory is the subdirectory that you want to delete (because of the cd part of the command shown above), remove all the remaining files, move up to your home directory, and use the rmdir command to get rid of the directory:

rm ./*; cd ..; rmdir delendum

The names of files on MathLAN often have cryptic letters like .ps or .gz at the end. What do those letters mean? Should I be attaching them to the names of files I create?

Some of the programs that are available on MathLAN give special treatment to files with names containing suffixes of this sort. The operating system itself pays no attention to them, so you can create files with whatever names you like; only the application programs (the Java compiler, Firefox, and the like) force you to use special conventions.

Here are some of the commonly seen suffixes and their conventional meanings:

Can I use FTP to move files to and from my MathLAN account?

Yes. If you're initiating the file transfer from a non-MathLAN computer, have your software send the request to our ftp server,

It is also possible to initiate file transfers from MathLAN computers, using the command-line interface ftp or the graphical interface gftp.

We also maintain an anonymous ftp server for some documents published by our students and faculty.

How soon after I graduate will my MathLAN account be removed? Can I arrange to keep it for a year or two longer?

The system administrator archives each graduate's home directory and removes each graduate's account on or shortly after July 1. You can ask him to delay the removal until some subsequent July 1 simply by sending him an e-mail request, specifying the year in which the account can be removed.

My question isn't answered here. What do I do?

Here are some sources of answers:

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