Department of Computing Imperial College London
Linux setup files

Within your file space there are files that are important to the setup of your account. These files are often known as 'dot' files because they are named with a dot prefix in order to prevent them being removed accidentally with any global remove commands. Most can be configured by users but we recommend that you do not touch these files, unless you know what you are doing (in any case, you should always make a copy of the original first).

Files that are executed when you log in or out

sourced when you first log in to a machine, and thus tends only to act on your console window.
executed by every shell that you run, it configures aliases and sets environment variables. Note that your .cshrc file should never generate output, as this will break many things (for example remote execution of commands via ssh).
not essential, used to load applications automatically on an X-based terminal.
not essential, executed on logout, it can be used to clean up temporay files, remove Kerberos tickets, etc.

Files that help with security

Your klogin is a list of trusted users who you will allow to login to your account without needing a password. This uses the Kerberos authentication system. This file must be world readable. However, unless there are very specific circumstances, .klogin is generally a bad idea. If you think you want to use .klogin, read the above document, and also preferably mail help and explain your circumstances.
This is a file created when you login that allows applications to communicacte with your display. Without it, you will not be able to open new windows. Therefore - Do not touch this file! The file actually contains a key with which applications can talk to your display, for more information see xauth.

Files that tell people about you (optional)

This file is appended to each mail you send, and to the bottom of each post to Usenet News. It normally contains some information about yourself, such as name and email address. It is generally considered bad 'netiquette' to have a .signature file longer than four lines.
This file is displayed when somebody uses finger to find information about you.
This file can be used to describe the work you are involved in.

Other important files

This file contains your incoming email.
These directories are created when a filesystem is browsed from a Macintosh. In most cases they just contain the infomation needed to support a consistent desktop view, e.g. icon locations, etc. However, some Macintosh applications store data in the 'resource fork' which lives in these directories so data could be lost if they are removed.

Files that can be removed from your account

Through the normal use of your account extra files will be created some of which can be safely deleted so as not to waste space. It is normal practice for the Department to allocate more space than is physically available on the system, since most users do not use up all of their allocated quota. If nobody cleaned up their junk files, space could quickly become short, it is therefore a good idea to remove all junk files from your account.

Managing your file system / Disk quota and temporary disk space

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