Using csh & tcsh

Preface

A shell is a command interpreter. You type commands into a shell, and the shell passes them to the computer for execution. UNIX systems usually provide several shell choices. This handbook focuses on two of the shells: C shell (csh) and an enhanced C shell (tcsh).

C shell (csh), a popular command interpreter that has its origins in Berkeley UNIX, is particularly suited for interactive use. It offers many features, including an ability to recall and modify previous commands, a facility for creating command shortcuts, shorthand notation for pathnames to home directories, and job control.

tcsh, an enhanced version of csh, is almost entirely upward compatible with csh, so whatever you know about the C shell you can apply immediately to tcsh. But tcsh goes beyond csh, adding capabilities like a general purpose command line editor, spelling correction, and programmable command, file, and user name completion.

Shells other than csh and tcsh may be available on your system. The two most significant examples are the Bourne shell (sh) and the Korn shell (ksh). The Bourne shell is the oldest of the currently popular shells and is the most widely available. The Korn shell was developed at AT&T and is most prevalent on System V-based UNIX systems. Both shells are fully documented elsewhere, so we won't deal with them here.

This handbook is designed to help you use csh or tcsh more effectively. By demonstrating what these shells can do for you, and illustrating techniques for using their ...