1. Shell ITEC400 Yukari Kitamura

2. What is shell? An interface between the user and OS A utility program to interact with the kernel A programming language

3. How has it been developed? The Bourne shell as a programming language in 1979. The C shell with additional features in the late 1970s. The Korn shell with the best part of both the Bourne and the C shell in the mid-1980s. The Bourne Again shell as modified version of the Bourne shell with features of both the C shell and the Korn shell in 1988.

4. How it work? Interpret and execute commands entered by user. Customize the user’s environment. Shell program (script).

5. Evaluation Shell makes it possible to interact with OS. Growing by several improvement in different type of shells. Standardization of different type of shells can make it better.

6. Reference Quigley, E. (2004). UNIX shells by example fourth edition. :Prentice Hall