Operating System Learning Note Series (ii)-Operating system structure

1, the operating system for the program and users to provide a certain service.

1. User interface

2. Program execution

3. I/O operation

4. File System operation

5, communication. In many cases, a process needs to exchange information with another process. There are two ways of this communication. One is between the two processes running on the same computer, and the other is running between processes on different computers that are connected by the network.

6. Error detection

7. Resource allocation

8, statistics. Need to record which users are using how many and what types of resources

9, protection and safety. Protection ensures that all access to system resources is controlled and that the system is safe from external intrusion.

2, command interpreter, such as the Shell in Linux, its main function is to get and execute the user-specified next command. The execution of these commands is done in two ways. The first way is that the command interpreter itself contains code to execute these commands, and the size of the command interpreter is determined by the number of commands that can be provided. Another way is to implement the vast majority of commands by a system program. For example, the command to delete a file in Linux RM file.txt searches for a file named RM (located under the Bin/folder in the root directory), loads the file into memory, and executes it with parameter file.txt.

3, the system call type, can be broadly divided into five categories: Process Control, file management, device management, information maintenance and communication.

Operating System Learning Note Series (ii)-Operating system structure