Is there something you want to do every time you log out: run a program that deletes temporary files, asks you a question, or prints a fortune to your screen? If you use the C shell, make a file named .logout (Section 3.3) in your home directory and put the commands there. Before a login C shell exits, it will read that file. A login bash reads .bash_logout, and zsh reads .zlogout. But not all shells are login shells; you might want these shells to read your logout-type file, too. Section 3.18 shows a fix for the Bourne and Korn shells; Section 3.8 and Section 3.4 have background information.
Some ideas for your logout file are:
A command like fortune to give you something fun to think about when you log out.
A command to list a "reminder" file — for example, work to take home.
A script that prompts you for the hours you've worked on projects so you can make a timesheet later.
The
command clear to erase your screen.
This keeps the next user from reading what you did.[2] In the
Mac OS X Terminal
application, command-k will delete the scrollback buffer. It also helps
to stop "burn-in" damage to old, monochrome monitors caused by
characters left over from your login session (though this is hardly a
concern nowadays; most of us have moved on to color screens that are not
subject to burn-in). (Some Unixes clear the screen before printing the
login: prompt. Of course, this
won't help users who connect with a data switch or port manager because
the connection will be broken before the next login prompt.)
If you connect to this host over a network, with a slow modem or on a data switch — and you don't see all the logout commands run before your connection closes — try putting the command sleep 2 (Section 25.9) at the end of the file. That makes the shell wait two seconds before it exits, which gives output more time to get to your screen.
—JP and SJC
[2] Some terminals and windows have "scroll back" memory of
previous screens. clear
usually doesn't erase all of that. To set scrollback in xterm, use the
-sb and -sl options. Most
other terminal emulators have similar mechanisms to set the
number of lines to keep in the scrollback buffer.