A shell is any program that takes input from the user, translates it into instructions that the operating system can understand, and conveys the operating system's output back to the user.
- Sh – simple shell
- BASH – Bourne Again Shell
- KSH – Korne Shell
- CSH – C Shell
- SSH – Secure Shell
- The sh shell was the earliest shell, being developed for UNIX back in the late 1970s.
- It is the most Popular-that is why it is bundled with every Unix System
- This is the shell used by many Unix users
- Steve Bourne’s Creation
- The csh shell was originally developed for BSD UNIX. It uses a syntax that is very similar to C programming.
- Created by Bill Joy
- Two Advantage over Bourne Shell
2. Command history feature – Previously typed commands can be recalled, since C shell keeps track of all commands issued at the command line.
Korn shell
- Very powerful
- Super set of Borne Shell
- Designed by David Korn of AT & T Bells Labs
- Offers lot more capabilities and decidedly more efficient than the other
- The bash shell is an improved version of the sh shell and is one of the most popular shells today. It’s the default shell used by most Linux distributions.
TSCH
- The tsch shell is an improved version of the C Shell.
It is the default shell used on FreeBSD systems.
ZSH (Z SHELL)
- The Z Shell is an improved version of the bash shell.
