What Is the C Shell?
This section provides a quick introduction of the C shell which offers a easier command syntax than Bourne shell for C programmers.
The C shell is a Unix shell introduced by Bill Joy in 1978.
The C shell was derived from the Thompson shell. It has a syntax modeled
after the C programming language.
The C shell has the following main features:
- Alias Substitution - The ability to define command aliases and use them in new commands.
- Arithmetic and Boolean Expressions - The ability to evaluate arithmetic and Boolean expressions in the way as the C language.
- Arrays - The ability to use variables with multiple elements, which could be numerically indexed.
- Built-in Commands - The ability to use a few useful commands built into the shell.
- Command Path Variable - The ability to define a list of paths where the shell can search for external program to execute.
- Command Substitution - The ability to execute extra commands in sub shells and uses their output in the command line.
- Execution Control Commands - The ability to execute commands conditionally and repeatedly.
- Execution Interruption Handling - The ability to catch execution interrupts and change execution flow.
- Filename Substitution - The ability to expand filename wildcard characters with real file names.
- History Substitution - The ability to reuse the entire command line, or some parts, of any previously executed command.
- Input and Output Redirection - The ability to change standard input and/or output from terminal console to other commands or files.
- Job Control - The ability to suspend an interactive job and resume it at a later time, or send it into the "background".
- Shell Scripts - The ability to execute commands stored in a script file.
- Quotation and Escape Sequences - The ability to protect special characters with single quotes and backslashes.
- Variable Substitution - The ability to reference values of built-in and user defined shell variables.
- Working Directory Stack - The ability to remember the current and previous working directories in a stack.
The picture below shows the paper on the C shell written by Bill Joy:
"An Introduction to the C shell"
Table of Contents
About This Book
1957 - FORTRAN Language Developed by IBM
1970 - UNIX Operating System Developed by AT&T Bell Labs
1971 - FTP Protocol Created by Abhay Bhushan
1972 - C Language Developed by Dennis Ritchie
1976 - vi Text Editor Developed by Bill Joy
1977 - Apple II Designed by Steve Jobs and Steve Wozniak
1977 - The Bourne Shell Developed by Stephen Bourne
►1978 - The C Shell Developed by Bill Joy
►What Is the C Shell?
C Shell Command Line
Command Line History Substitution
Command Line Alias Substitution
Command Line Input and Output Redirection
Command Line Variable Substitution
C Shell Command Line Examples
".cshrc" - C Shell Script File and
1978 - Bash (Bourne-Again Shell) Developed by Brian Fox
1979 - The Tcsh (TENEX C Shell) Developed by Ken Greer
1983 - "Sendmail" Mail Transfer Agent Developed by Eric Allman
1984 - Macintosh Developed by Apple Inc.
1984 - X Window System Developed a MIT Team
1991 - WWW (World Wide Web) Developed by Tim Berners-Lee
1991 - Gopher Protocol Created by a University of Minnesota Team
1995 - Java Language Developed by Sun Microsystems
1995 - PHP: Hypertext Preprocessor Created by Rasmus Lerdorf
2002 - .NET Framework Developed by Microsoft
PDF Printing Version