Operating System and Shell
1. “reject the shell is like rejecting all gears except first in your car” – explain . (gear in the car is use to adjust its speed , same as the shell in the operating system we cannot interact with the kernel and do something to the settings without it)
2. What is the use of options in the command?( Options determine how the command operates)
3. What is the use of arguments in the command?( arguments determine what it operates on)
4. Who develop “bourne shell”?( Stephen L. Bourne)
5. From where the oldest shell had been found?(the oldest shell has been found outside museums)
6. what is the objective of the development of the oldest shell? (for “Unix version Bourne shell sion 7”)
7. What are the steps performed by shell? (In order)
1. Read a command from the terminal (or the file)
2. Validate the command
3. Run the command directly or start the corresponding program
4. Output the result to the screen (or elsewhere)
5. Continue at step 1.
8. What is the standard shell used in linux distributions? (bash/bourne-again shell)
9. What are the steps of computer’s operations?
1. The computer waits for user input
2. The user selects a command and enters it via the keyboard or mouse
3. The computer executes the command
10. What is the importance of shell? (without shell, a user cannot do anything on the system because it acts as the interface between the user and the operating system)
11. What are the two kinds of shell commands?(describe each)
=Internal commands These commands are made available by the shell itself. The
Bourne-again shell contains approximately 30 such commands, which can be executed very quickly. Some commands (such as exit or cd) alter the state of the shell itself and thus cannot be provided externally.
External commands The shell does not execute these commands by itself but launches executable files, which within the file system are usually found in directories like /bin or /usr/bin.
12. Give the