PPT Slide
The Shell game
- Most users perceive the “Operating System” not through direct interaction with the kernel through system calls but rather through the command interpreter or shell program
- The shell provides a user interface to the O/S; traditionally a non-GUI environment
- Figure 3.18: Level view and “onion layer” view of shell’s role
- Basic structure of a shell: accept user input, interpret either as internal or external command, if external then fork()/exec()/wait()