4.2. The History of the Shell
When AT&T software engineers Dennis Ritchie and Ken
Thompson were designing UNIX™, they wanted
to create a way for people to interact with their new system.
Operating systems at that time came with command
interpreters, which could take commands from the user and
interpret them into something computers could use.
But Ritchie and Thompson wanted something more, something
that offered better features than the command interpreters
available at that time. This led to the development of the
Bourne shell (known as sh), created by S.R.
Bourne. Since the creation of the Bourne shell, other shells
have been developed, such as the C shell
(csh) and the Korn shell
(ksh).
When the Free Software Foundation sought a royalty-free
shell, developers began to work on the language behind the
Bourne shell as well as some of the popular features from other
shells available at the time.
The result was the Bourne Again Shell, or
bash. Although your Red Hat Enterprise Linux system includes
several different shells, bash is the default
shell for interactive users. You can learn more about
bash by reading the bash
man page (type man bash at a shell prompt).