Your shell is the most important part of your working environment. The shell is what interprets the commands you type on the command line, and thus communicates with the rest of the operating system. You can also write shell scripts a series of commands to be run without intervention.
Two shells come installed with FreeBSD:
csh and sh.
csh is good for command-line work, but
scripts should be written with sh (or
bash). You can find out what shell you have
by typing echo $SHELL.
The csh shell is okay, but
tcsh does everything csh
does and more. It allows you to recall commands with the arrow
keys and edit them. It has tab-key completion of filenames
(csh uses the Esc key), and
it lets you switch to the directory you were last in with
cd -. It is also much easier to alter your
prompt with tcsh. It makes life a lot
easier.
Here are the three steps for installing a new shell:
Install the shell as a port or a package, just as you would any other port or package.
Use the chsh command to change your
shell to tcsh permanently, or type
tcsh at the prompt to change your shell
without logging in again.
It can be dangerous to change root's shell to something
other than sh or csh on
early versions of FreeBSD and many other versions of UNIX®; you
may not have a working shell when the system puts you into
single user mode. The solution is to use su
-m to become root, which will give you the
tcsh as root, because the shell is part of
the environment. You can make this permanent by adding it to
your .tcshrc file as an alias with:
alias su su -m
When tcsh starts up, it will read the
/etc/csh.cshrc and
/etc/csh.login files, as does
csh. It will also read the
.login file in your home directory and the
.cshrc file as well, unless you provide a
.tcshrc file. This you can do by simply
copying .cshrc to
.tcshrc.
Now that you have installed tcsh, you can
adjust your prompt. You can find the details in the manual page
for tcsh, but here is a line to put in your
.tcshrc that will tell you how many
commands you have typed, what time it is, and what directory you
are in. It also produces a > if you are an
ordinary user and a # if you are root, but
tsch will do that in any case:
set prompt = "%h %t %~ %# "
This should go in the same place as the existing set prompt
line if there is one, or under "if($?prompt) then" if not.
Comment out the old line; you can always switch back to it if
you prefer it. Do not forget the spaces and quotes. You can get
the .tcshrc reread by typing
source .tcshrc.
You can get a listing of other environmental variables that
have been set by typing env at the prompt.
The result will show you your default editor, pager, and
terminal type, among possibly many others. A useful command if
you log in from a remote location and can not run a program
because the terminal is not capable is setenv TERM
vt100.
All FreeBSD documents are available for download at http://ftp.FreeBSD.org/pub/FreeBSD/doc/
Questions that are not answered by the
documentation may be
sent to <[email protected]>.
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