The History of the Shell

In the days when AT&T's Dennis Ritchie and Ken Thompson were designing UNIX^TM, they wanted to create a way for people to interact with their new system.

Operating systems at the time came with command interpreters, which could take commands from the user and interpret them so the machine could use them.

But Ritchie and Thompson wanted something more, something that offered better features than the command interpreters of the day. This lead to the development of the Bourne shell (known simply 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.

By now, you may have seen the word bash when you have mistyped commands at the shell prompt (as in bash: somecommand: command not found).

More about bash

You can learn more about bash by reading the bash man page. At the shell prompt, type man bash (or you can save the file as a text file by typing man bash | col -b > bash.txt, which you can then open to read with an editor like pico or a pager like less. You can also print the file with man bash | col -b | lpr, but be warned: it is a large file. If you want more information, O'Reilly & Associates publishes Learning the bash Shell, by Cameron Newham and Bill Rosenblatt.

Although your system came with several different shells, bash is the default shell for Red Hat Linux.