Question

Two different approaches to implementing a command interpreter are theself-contained and system-program approaches. In self-contained approach, implementation of the commands is included within the module. On the other hand, the system program approach invokes a system program for most commands. List advantages and disadvantages of each approach.

Answer 1

Advantages and disadvantages of 2 approaches:

Self-Contained Approach	System-Program Approach
In this, upon issuing the command, interpreter jumps to the appropriate section of the code, executes the command and returns the control back to the user.	In this, the interpreter loads the appropriate program into memory along with the appropriate arguments.
Advantage is: Its Speed and Overall simplicity	Advantage is: New commands can be added without altering the command interpreter.
Disadvantage is: To add the new commands, we need to rewrite the interpreter program. This may get complicated, messy or too large after a number of modifications.	Disadvantage is: Speed will get reduced as it loads the entire program along with parameters into the memory.