To start emacs at the command prompt, type in 'emacs' (without quotes) and press enter.

Emacs has a pretty good tutorial, if you open emacs and then hold down Ctrl and press \ and then type in t, ( Ctrl-\ t ) the tutorial will open.

See the vi tutorial. Run the command 'vimtutor' (without quotes) from any shell. (Note: we are using VI iMproved, which adds some functionality to the original program, and has online help, which you may access in vi by typing ':help').

You need to login to password.cs.brandeis.edu and use the command 'passwd'. You will need to enter your old password and then you will need to enter the new password twice.

Alternatively, the command 'passwd' on any cs local host should explain this to you, and redirect you to password.cs.brandeis.edu. If this does not happen, please email guru with the date and approximate time that you ran the command, and the machine on which you ran it.

The password change should take effect approximately at the top of the hour.

Create (if necessary) the file /mnt/mail.cs.brandeis.edu/`whoami`/.forward (`whoami` evaluates to your username) by using your favorite text editor (emacs, pico, vi, etc.). The first and only line of your file should be the e-mail address you want your mail to be forwarded to.

NOTE: This only forwards new, incoming mail that is sent to you. It does NOT transfer your existing mail from your cs account to the account you are forwarding your mail to.

We recommend not using Outlook as it has been used to propogate worms in the past.

Download a Macintosh-compatible Usenet client, or configure pine to talk to the nntp server of your choice.

In the lounge adjoining the Berry Patch there are four ethernet ports availible for laptops. To use them you will need to set your TCP/IP connection to DHCP, so that you will be automatically given an IP address (this is default on most machines).

You may have a process that is taking up a lot of CPU usage. To see if that's the case, type ps at the command prompt. You will see something like the following:

	  PID TTY        TIME CMD
	13391 pts/3  00:00:00 tcsh
	13470 pts/3  00:00:01 emacs
	13974 pts/3  00:00:00 ps

To get rid of a process, type kill -1 PID where PID is the number in the PID column. For instance, to get rid of emacs in the above example, the user would type kill -1 13470. This should clean the process up nicely. If after a short while, ps still shows that process, type kill -9 13470.

On Linux you can also use the graphical utility ksysguard.

First, make sure that the scanner is on. (The power buttons is on the front.) Next, open ImageCapture.app in the /Applications folder. Click "Overview," then select which section of the image you wish to scan by dragging the selection box. Click "Scan." When the scanner is finished scanning, you image will be in ~/Pictures.

PDF (portable document format) files are viewable documents. You can view a .pdf file using evince on Gnome, kpdf on KDE, or Preview on Mac OS X.

First of all note that UNIX is case sensitive (i.e. "Blah" is not the same as "blah"). If that didn't help, stop by the guru office with a photo ID (we accept IDs issued by: Brandeis University, the state of Massachusetts, and the United States Federal Government), and ask a guru to change your password. The System Operators can change your password, but they DO NOT know what your password is.

Undergraduates have 30 MB of disk space.

Graduate students are not on a specific quota, but are asked to keep their disk usage reasonable.

To find out how much space your directory is taking up right now type 'cd; du -sm'. This will summarize what you're using, in MB. The web directory has a separate "hard" quota of 7.5MB or 1500 files. The hard quota implies that you can not store more than your quota in web directory even temprarily, in contrast to your home directory where it's generally allowed on temporary basis.

You don't have to logout if you're leaving for a short period of time, but you do need to lock your terminal before leaving it. To do so, you can set your screen saver to activate automatically and require a password to unlock (good), and/or lock your screen manually before leaving it (better).

To configure your screen saver:

• In Gnome, from the taskbar select System → Preferences → Screensaver. Use the slider to select a value for "Regard the computer as idle after" (suggested: 5 minutes, or less), and select the "Activate screensaver when computer is idle" and "Lock screen when screensaver is active" checkboxes.
• In KDE, right click on the desktop, click configure desktop, and select screen saver from the panel on the left. Select the "Start automatically" and "Require password to stop" checkboxes, and use the up/down arrows to set appropriate time values for each (suggested: 5 minutes or less for activation, 1 second until password required).
• In Mac OS X, from the menu bar select Apple menu → System Preferences... → Desktop & Screen Saver → Screen Saver. Use the slider to select a value for "Start screen saver" (suggested: 5 minutes, or less). You can also configure "Hot Corners" to activate or disable the screen saver at will by clicking on the "Hot Corners..." button in this preference pane.

Because someone else could potentially take over your session after you leave your workstation but before your screen saver has time to activate, we strongly suggest that you lock your screen manually before walking away from it.

• You can lock your screen at any time by going to KMenu (in KDE) or Actions (in GNOME) and clicking on lock screen or lock session, or by using "Hot Corners" to activate your screen saver on Mac OS X.
• You can place a Lock/Logout padlock icon in your panel in KDE by right clicking on the panel and selecting Add > Applet → Lock/Logout Applet from the drop-down menu.
• You can do the same in GNOME by right-clicking on the toolbar, selecting "Add to panel" and choosing the Lock screen and/or Logout icons from the list of available options.
• In Mac OS X open /Applications/Utilities/Keychain Access.app, from the menu bar select Keychain Access → Preferences... → General, and select the "Show Status in Menu Bar" checkbox. This will place a small padlock icon in your menu bar, from which you can select "Lock Screen" to lock your screen at any time. This is the recommended method of locking your screen in Mac OS X.
• If you are logged into a linux tty/vterm (ctrl alt F1-F6), you can lock your console with the vlock(1) command.

Note that you should only use screen saver for a short period of time (10 minutes or less). Please be sure to save your files before using screen saver. Very often people walk in to the lab and reset the X server, logging you off and destroying any unsaved work.

All files and directories have permissions on them which describe who is allowed to do what with them. You can see the permissions on a file or folder by running ls -l. Permissions have have a form of 10 character string that is grouped as follows:

• The first character describes what the item is. Files are marked with -, and directories are marked with d.
• The next three characters (2 through 4) correspond to permissions for u, the user who owns the item.
• The next three characters (5 though 7) correspond to permissions for g, the group that the item belongs to. These permissions apply to users who are members of the item's group, but do not own the item.
• The last three characters (8 through 10) correspond to permissions for o, for "other" or "world." These permissions apply to everyone else.

Except for the item description character, each set of three characters is organized in the same way:

• The first character is r if reading is allowed, or - is reading is not allowed.
• The second character is w if writing is allowed, or - is writing is not allowed.
• The third character is x if executing the file is allowed, or - is executing the file is not allowed.

For files, these permissions are fairly self explanatory: read allows you to read the file, write allows you to edit the file, and execute allows you to run a file (like a shell script). For directories, read allows you to see the contents of the directory, write allows you to create and delete files in the directory, and execute allows running programs (including a web browser) to access the files in the directory.

Keep in mind that even if you disallow someone from editing a file by denying them write access, if the directory allows them write access, they can read the file, copy its contents, and then delete and recreate the file with whatever permissions they desire. If you deny write access to a directory, but allow write access to the parent directory, they can delete and recreate the whole directory in the same way. Be careful with who you give write access to!

To change permissions on a file or folder, use the command chmod <mode> <file>, where <mode> is how you want to change the permissions, and <file> is the file or folder whose permissions you want to change. To describe to chmod how you wish to change the permissions of the file, you can either describe only the change you wish to make, or describe the permissions for the file as a whole.

To describe just the permission change, the mode will be a character representing the group you want to change (u for user/owner, g for group, o for other/world, or a for all three) followed by a character representing how you want to change the permission (+ to grant the permission, - to revoke it), followed by a character representing the permission to change (r for read, w for write, x for execute). For example, to remove write permissions for other on a file, the mode is o-w, while to add execute permissions for everyone, the mode is a+x. You can also combine multiple groups and and permission settings in one mode: to add read access for user and group, but not other, you the mode is ug+r, while to remove write and execute permissions for other, the mode is o-wx.

To describe the permissions for the file as a whole, we use a number, instead of a string of characters. Each permission type is assigned a number: read is 4, write is 2, execute is 1. The mode we will use is a set of three sums, one for each permissions group. For example, let's say we want user to have read, write, and execute access, group to have read and execute access, and other to have read access only. The sum for user is 4+2+1=7, the sum for group is 4+0+1=5, and the sum for other is 0+0+1=1, so the mode is 751.

Change your password immediately and send mail to guru and chris.

Put webpage files in the .www directory in your home directory. (If this directory does not yet exist, just create it: mkdir ~/.www)

To access your home page from a web browser, go to http://www.cs.brandeis.edu/~<user>, where <user> is your CS account username.

We do backups between midnight and 7 am. Any file which didn't exist overnight won't be backed up at all. If it existed for a week, we keep it on backup for several months. If it existed when we did the first backup of the month, we keep it for several years.

If you accidentally delete a file which has existed for less than a week, the sooner you tell us, the better the chance that we will be able to restore the file.

And no, there is NO way to undelete a file once you've erased it using rm.

Alternatively, you could use command can instead of rm (you can alias rm to can by alias rm can). can puts the deleted files into a garbage can. You can list the files in the garbage can by command sniff and undelete by rummage file-name(s). NOTE: the garbage can is on local disk, that means you can only undelete the file if you're on the same machine you deleted it from.

Due to security considerations we do not allow CGI scripts on the system.

Nope. The only thing you can achieve is to lose your account as well. People caught sharing account will have their account suspended and, in case of repeated offense -- disabled.

Chain letters are bad. They're annoying, they interfere with work and take up resources that can be put to better use. (By the way, they don't actually take you to Disneyworld. They collect winners in a bus and send them off a cliff.) Also, forwarding chain letters is a violation of the Usage policy.

This is a problem that appears under the Gnome desktop manager. Windows are minimized to the Gnome Pager, which has been known to vanish mysteriously. To restore it, right-click on the Gnome taskbar, and select the menu option Add Applet→Utility→Gnome Pager.

The Mozilla family of browsers checks to see if another process is already using a profile by looking for the existence of a file named .parentlock in your profile. If a browser process dies or otherwise fails to exit cleanly, it can sometimes leave this lock file behind (the lock file should be present while the browser is running).

In Linux, this file will exist at ~/.mozilla/$BROWSER/$PROFILE/.parentlock, in OSX it exists at ~/Library/Application Support/Firefox/Profiles/$PROFILE. $PROFILE usually takes the form of eight random characters followed by a '.' and the string 'default' or 'Default User'.

On Linux you may locate this file by hand (cd; ls -Ra .mozilla | less, use '/' to enter a search query, look for .parentlock), or with the following command (NOTE: This will remove *all* instances of .parentlock in your .mozilla directory. Do not use this command without first exiting all Mozilla-family browser sessions on any machines you may be logged into.):

cd; find .mozilla -name \.parentlock -exec rm -v {} \;

On Mac OS X you may locate this file by hand (ls -Ra ~/Library/Application\ Support/Firefox/Profiles/ | less, use '/' to enter a search query, look for .parentlock), or with the following command (NOTE: This will remove all instances of .parentlock in your .mozilla directory. Do not use this command without first exiting all Mozilla-family browser sessions on any machines you may be logged into.):

cd; find ~/Library/Application\ Support/Firefox/Profiles/ -name \.parentlock -exec rm -v {} \;