Linux system call Knowledge

Q1. What is a system call? Why introduce a system call?

A:

1) Operating System
provides a set of interfaces for user-space processes and interactions with hardware devices such as CPUs, disks, and printers. These interfaces make the program more portable, because different operating systems
can be compiled correctly and on top of these operating systems
as long as the provided set of interfaces are the same. Executing the same program, this set of interfaces is called "system call";

2) The reasons for introducing system calls are:

A. This makes programming easier;

B. This greatly improves the security of the system;

C. Most importantly, these interfaces make the operating system more portable.