Beyond Linux® From Scratch (systemd Edition) - Version 12.1

Chapter 7. Shells

Tcsh-6.24.10

Introduction to Tcsh

The Tcsh package contains “an enhanced but completely compatible version of the Berkeley Unix C shell (csh)”. This is useful as an alternative shell for those who prefer C syntax to that of the bash shell, and also because some programs require the C shell in order to perform installation tasks.

This package is known to build and work properly using an LFS 12.1 platform.

Package Information

Installation of Tcsh

Install Tcsh by running the following commands: 

./configure --prefix=/usr &&
make

To test the results, issue: make check.

Now, as the root user: 

make install install.man &&

ln -v -sf tcsh   /bin/csh &&
ln -v -sf tcsh.1 /usr/share/man/man1/csh.1

Command Explanations

ln -v -sf tcsh /bin/csh: The FHS states that if there is a C shell installed, there should be a symlink from /bin/csh to it. This creates that symlink.

Configuring Tcsh

Config Files

There are numerous configuration files for the C shell. Examples of these are /etc/csh.cshrc, /etc/csh.login, /etc/csh.logout, ~/.tcshrc, ~/.cshrc, ~/.history, ~/.cshdirs, ~/.login, and ~/.logout. More information on these files can be found in the tcsh(1) man page.

Configuration Information

Update /etc/shells to include the C shell program names (as the root user): 

cat >> /etc/shells << "EOF"
/bin/tcsh
/bin/csh
EOF

The following ~/.cshrc provides two alternative colour prompts and coloured ls output. If you prefer a global modification, issue the command as the root user, replacing ~/.cshrc by /etc/csh.cshrc. 

cat > ~/.cshrc << "EOF"
# Original at:
# https://www.cs.umd.edu/~srhuang/teaching/code_snippets/prompt_color.tcsh.html

# Modified by the BLFS Development Team.

# Add these lines to your ~/.cshrc (or to /etc/csh.cshrc).

# Colors!
set     red="%{\033[1;31m%}"
set   green="%{\033[0;32m%}"
set  yellow="%{\033[1;33m%}"
set    blue="%{\033[1;34m%}"
set magenta="%{\033[1;35m%}"
set    cyan="%{\033[1;36m%}"
set   white="%{\033[0;37m%}"
set     end="%{\033[0m%}" # This is needed at the end...

# Setting the actual prompt.  Two separate versions for you to try, pick
# whichever one you like better, and change the colors as you want.
# Just don't mess with the ${end} guy in either line...  Comment out or
# delete the prompt you don't use.

set prompt="${green}%n${blue}@%m ${white}%~ ${green}%%${end} "
set prompt="[${green}%n${blue}@%m ${white}%~ ]${end} "

# This was not in the original URL above
# Provides coloured ls
alias ls ls --color=always

# Clean up after ourselves...
unset red green yellow blue magenta cyan yellow white end
EOF

Contents

Installed Program: tcsh
Installed Libraries: None
Installed Directory: None

Short Descriptions

tcsh

is an enhanced but completely compatible version of the Berkeley Unix C shell, csh. It is usable as both an interactive shell and a script processor