Internet Channel

My mailbox is corrupt and I can't retrieve my mail. What do I do?

This can happen if you try to access mail with both a pop client (like Eudora or Netscape Mail) and your shell account (pine, elm, mutt) at the same time. Sometimes it also happens if you hit the "Get Mail" button in your pop client repeatedly while it's trying to download.

If you're unsure of what you're doing, you can call us. However, you can fix this yourself if you use a shell account by editing the file /var/mail/yourusername. Each mail message begins with a "From" followed by a space, followed by more information like this:

From CMacl54033@aol.com  Sun Apr  5 21:15:03 1998
Return-Path: 

Received: from imo29.mx.aol.com (imo29.mx.aol.com [198.81.17.73])
          by arutam.inch.com (8.8.5/8.8.5) with ESMTP id VAA02757
          for ; Sun, 5 Apr 1998 21:15:00 -0400 (EDT)
[etc.]

If it doesn't, then the mail programs you use won't recognize it as a mail file. You can delete the message that has the incorrect headers, and make sure that it starts off with one that has clean headers.

WARNING: Back up your mail file before starting:

$ cp /var/mail/yourusername /tmp/yourusername.mail.backup
$ chmod 600 /tmp/yourusername.mail.backup

Warning!Do your editing quickly because if you receive a message while you're editing the file, you can corrupt your mailbox again or lose the incoming message. The second command above makes sure the file is readable only by you.

How do I stop other people from finger'ing me?: If you would like to remain "anonymous" when it comes to finger info, you have two options. One is to run chfn from your shell account and change all of your personal info in there. The other, more private option is to create an empty .nofinger file and place that in your shell account. This will make you invisible to the finger command.

How do I change permissions on my files?

Note: There are 3 different categories for which you have to set permissions: user, group, and everyone. To permit people to view your files and execute your cgi-bins, you need the following.

r=read, w=write, x=eXecute


	        	user	group	everyone
 cgi-bin files		rwx	rx	rx
 all other files	rw	r	r
 (text,html,gif,
	 jpg, etc.)

In other words, for text/html/gif/jpg/etc files,
user: read,write group: read everyone: read

For cgi-bin scripts, you should have:
user: read,write,execute group: read,execute everyone: read,execute

Here's how you do it with some common programs.
ws_ftp
Highlight the file for which you would like to change permissions. Right click your mouse on the file and then a menu should pop up. Select "chmod(UNIX)". A window with the permissions should come up, and this is where the permissions can be changed. Use the information above.
fetch
Highlight the file you would like to change permissions on, go to the menu at the top and pull down "Remote" then select "Set Permissions" and that is where you can change permissions.
CuteFTP
Highlight the file for which you would like to change permissions, right click your mouse on the file, and then a menu should pop up. Select "Change file attributes" and that is where you can change the permissions. in this program in particular, when the file attributes window opens up, it does not have the files' current settings, so you have to fill in the settings exactly as you want them, not just the changes from the original settings.
UNIX
In UNIX (ftp or command line) for a text/html file, you would type "chmod 644 <the file name>".
For a cgi script, at the prompt you would type "chmod 755 <the file name>".

How do I use traceroute and ping to tell if the Internet is slow?

There are two ways users can check their Internet connection, Ping and Traceroute. Two commands which can be executed from a command prompt in your shell account. By typing traceroute <remote IP address> it will show you the connection route to the remote computer from your current connection. Typing ping <remote IP address> sends packets to the remote machine and waits for a reply (a pong) :), it then determines the delay time between the two computers.

Ping is generally a better means of checking connectivity on the Internet. Ping times of under 100ms on the internet are very good. Times under 50ms are superb, times of 10ms or less usually means you are on the same network.

Do you have any quick setup guides for pgp?

Make a directory for your pgp files readable only by you.
mkdir .pgp;chmod 700 .pgp
Generate a key
pgp -kg
Extract my key using ascii armor (so other people can fetch your public key).
pgp -kxa "Your Name <you@inch.com>" .pgp/pubring.pgp
Add someone's key
pgp -ka <file_with_key>
Put your key in your .plan so others can get it.
cp .pgp/pubring.asc .plan; chmod 644 .plan

Note, we've experienced a problem when we finger an account to get someone's public key. The information appears correct, but when you cut and paste, the keys don't match. Thus, you'll probably have to email your public key to them or put it on your webpage until we find what's wrong.