Linux Basics (top)

The history of 1.Linux: Linux was developed by a college student named Linus Torvalds of the University of Helsinki in 1991, and Linux is the name of the operating system kernel.

2. Embedded System: The so-called embedded system refers to a non-computer system with microprocessors, such as MP3 players, industrial equipment, automotive electronic equipment, handheld devices, information appliances, such as embedded systems used. Linux with its core stability, high reliability, good real-time, can be cut, the core is small, support a variety of development language advantages become a lot of embedded system manufacturers optimistic One Direction. According to the survey, more than 50% of embedded systems tend to use Linux as an operating system.

To the point ...

The main features of 3.Linux include stability, compatibility, portability, user interface, and more.
Here's a detailed description:

3.1-- Multi-user multitasking:
Linux enables multiple users to use the same computer (multi-user)from the same or different terminals without the restriction of a commercial software license.
During the same time period, Linux can respond to different requests from multiple users, or it can execute multiple programs (multitasking)simultaneously in Linux.

3.2-- height stability :
Linux kernel design inherits the excellent characteristics of UNIX, it can run efficiently and stably for a long time. Linux's infrastructure is made up of unrelated layers, each with specific features and strict permissions to ensure that Linux runs at maximum stability.

3.3-- Good compatibility :
Linux adheres to the POSIX (portable Operating system Interface of Unix) standard, so Linux is compatible with today's mainstream UNIX systems such as SYSTEMV and BSD, and can be executed under UNIX system systems, It can also run almost entirely on Linux.

3.4-- Powerful Portability :
Because Linux system kernel is only less than 10% of the source code is written in assembly language, the rest are in C language to complete, so the platform portability is very strong. Whether it's handheld, PC, minicomputer or midsize, or even mainframe computers, Linux is the most supported operating system to support the hardware platform.

3.5-- supports multiple file systems :
Linux can incorporate many different file systems, such as Windows98 's fat16/32,windows nt/2000 NTFS, OS/2 HPFS, or even File system NFS shared by other computers on the network, in a way that mounts. are Linux supported file systems.

3.6-- Efficient memory management :
Linux accelerates the execution of a program by using unused memory areas as buffers (buffer). In addition, the system will use the memory protection mode to execute the program, to avoid the failure of one program to cause the whole system to crash.

3.7-- Graphical user interface :
Linux provides two types of user interfaces:
The character interface, the traditional UNIX interface, is the user's keyboard input command to perform the relevant operation.
Graphical user interface-can be manipulated using the mouse, the expression is vivid and direct, and the same as in the windoows operation.

3.8-- Perfect Network functions :
Linux inherits the advantages of UNIX as a network operating system, using TCP/IP as the default network communication protocol. In addition, it contains many server software, such as Apache (WWW server), Sendmail (mail server), VSFTPD (FTP server), Squid (proxy server), etc., so there is no need to purchase additional software, Can directly use Linux as a full-service network server.

4.the kernel version number of Linux is composed of three numbers , generally expressed as x.y.z, such as 2.4.18. Where:
X represents the major version number, which is usually relatively stable over time.

Y represents the minor version number, and if it is even, it means that the kernel version is a formal version (or a stable core version) that can be used in the actual product, and if it is odd, the kernel is a beta version (or the core version of development), is not very stable, the function is not perfect, For testing only.

Z represents the version number of the patch, and the larger the number, the greater the number of modifications, the more complete the version.

Linux Basics (top)