FreeBSD csh / tcsh: Export Shell Variable
Q. I'm using FreeBSD 7 with csh (tcsh) shell. How do I export shell variable under FreeBSD operating systems?
A. tcsh is an enhanced but completely compatible version of the Berkeley UNIX C shell, csh. It is a command language interpreter usable both as an interactive login shell and a shell script command processor. It includes a command-line editor and many other features.
FreeBSD display current environment variables
Type the following command to print current names and values of environment variables:
setenv
Sample output:
SHELL=/usr/local/bin/bash TERM=xterm SSH_CLIENT=10.10.29.66 37484 22 SSH_TTY=/dev/ttyp2 USER=root PAGER=more FTP_PASSIVE_MODE=YES PATH=/sbin:/bin:/usr/sbin:/usr/bin:/usr/games:/usr/local/sbin:/usr/local/bin:/root/bin MAIL=/var/mail/root BLOCKSIZE=K PWD=/root SHLVL=2 HOME=/root LOGNAME=root SSH_CONNECTION=10.10.29.66 37484 10.24.116.2 22 _=/bin/csh HOSTTYPE=FreeBSD VENDOR=unknown OSTYPE=FreeBSD MACHTYPE=unknown GROUP=wheel HOST=vps.nixcraft.in REMOTEHOST=10.10.29.66 EDITOR=vim
Export shell variable
To export and set new environment variables, enter:
setenv name value
setenv EDITOR /usr/bin/vim
You need to add all your enviorment variables to ~/.cshrc file - csh resource script, read at beginning of execution by each shell. Here is my sample .cshrc file:
alias h history 25
alias j jobs -l
alias la ls -a
alias lf ls -FA
alias ll ls -lA
# A righteous umask
umask 22
set path = (/sbin /bin /usr/sbin /usr/bin /usr/games /usr/local/sbin /usr/local/bin $HOME/bin)
setenv EDITOR vim
setenv PAGER less
setenv BLOCKSIZE M
if ($?prompt) then
# An interactive shell -- set some stuff up
set prompt = "`/bin/hostname -s`# "
set filec
set history = 100
set savehist = 100
set mail = (/var/mail/$USER)
if ( $?tcsh ) then
bindkey "^W" backward-delete-word
bindkey -k up history-search-backward
bindkey -k down history-search-forward
endif
endif
A list of commonly used environment variables
An array of strings called the environment is made available by execve() call when a process begins. By convention these strings have the form name=value. The following names are used by various commands
- BLOCKSIZE : The size of the block units used by several commands, most notably df, du and ls. BLOCKSIZE may be specified in units of a byte by specifying a number, in units of a kilobyte by specifying a number followed by K or k, its of a megabyte by specifying a number followed by M or m etc.
- COLUMNS : The user's preferred width in column positions for the terminal. Utilities such as ls and who use this to format output into columns.
- EDITOR : Default editor name.
- EXINIT : A startup list of commands read by ex and vi.
- HOME : A user's login directory, set by login from the password file /etc/passwd.
- LANG : This variable configures all programs which use setlocale to use the specified locale unless the LC_* variables are set.
- MAIL : The location of the user's mailbox instead of the default in /var/mail, used by mail, sh, and many other mail clients.
- PAGER : Default paginator program. The program specified by this variable is used by mail, man, ftp, etc, to display information which is longer than the current display.
- PATH : The sequence of directories, separated by colons, searched by csh, sh, system, execvp, etc, when looking for an executable file. PATH is set to /usr/bin:/bin initially by login.
- PRINTER : The name of the default printer to be used by lpr, lpq, and lprm.
- PWD : The current directory pathname.
- SHELL : The full pathname of the user's login shell.
- TERM : The kind of terminal for which output is to be prepared. This information is used by commands, such as nroff or plot which may exploit special terminal capabilities.
- TMPDIR : The directory in which to store temporary files. Most applications use either /tmp or var/tmp. Setting this variable will make them use another directory.
- TZ : The timezone to use when displaying dates.
- USER : The login name of the user.
Further readings:
- man page - csh, tcsh
Capture each and every moment of life with a FREE 4 GB SD memory card with the purchase of select digital cameras from Canon, Nikon, Pentax and others from Amazon
E-mail
Print
Can't find an answer to your question? Contact us
Related Other Helpful FAQs:
Discussion on This FAQ
Leave a Reply
We encourage your comments, and suggestions. But please stay on topic, be polite, and avoid spam. Thank you very much for stopping by our site!
Tags: berkeley unix, command language interpreter, command processor, environment variables, login shell, set PATH, setenv command, shell script, shell variable, tcsh shell, unix c shell, variables type
September 2nd, 2008 at 3:48 pm
Might interest you to know that when I read your posts in my RSS Google Reader, I always get a pop-up demanding some credentials.
See: http://wiki.xdroop.com/gallery2/v/Random/0809/20080902-1140001.jpg.html