IN THIS CHAPTER
The history of the tcsh shell
Parts of tcsh
Using the tcsh shell
Another popular alternative shell available in the Linux world is the C shell. The C shell, as you might guess, is somewhat of an attempt to incorporate features found in the C programming language into shell scripting. The most popular version of the C shell implemented in open source is the tcsh shell. This chapter discusses the tcsh shell, describing its features, and showing how to write shell scripts for it.
The C shell was developed at the University of California, Berkeley by Bill Joy as a replacement for the original Unix shell created at AT&T Labs (before there was even a Bourne shell). Developers at Berkeley had designed and built a Unix system to compete with AT&T Unix, and the C shell was their choice for the default shell. This version of Unix is popularly called the Berkeley Software Distribution (or BSD Unix). The goal of the C shell was to provide a command line and scripting environment that C programmers would be comfortable with.
In the late 1970s Ken Greer created an extension to the C shell that added command line editing features found in the TENEX operating system. This is where the name tcsh came from. The tcsh shell has become a popular shell for many Unix systems patterned after BSD Unix (including early versions of the Mac OS X operating system; newer versions now use the bash shell as the default).
While the bash shell has become ...