Question

Problem 5: (3 points) What is the purpose of the command interpreter? Why is it usually separate from the kernel? What system calls have to be executed by a command interpreter or shell in order to start a new process?

Answer 1

The main purpose of a command interpreter is to read commands received from the user or from any command files and execute them through the process of turning these commands into system calls.

As command interpreters are changeable in nature they are not the part of the kernel.

In order to start a new process the system call known as fork and followed by the system call exec must be executed by a command interpreter.

Explanation:

An important part of an operating system that is used for receiving and executing the commands that are received from the user. It is also termed as the shell in some of the operating systems.It is usually separated from the Kernel because it is changeable in nature. It depends on the user who gives commands.

In the Unix operating systems, the system call that must be executed by the command interpreter for the purpose of starting a new process is a fork system call and it must be followed by exec system call for execution. The process that is currently executed will be cloned by a fork system call and exec helps in the execution of the calling process.