What are the five major factors that led to the emergence and development of Linux?

Five major factors for the emergence and development of Linux: 1. The UNIX operating system is a time-sharing operating system developed on the DEC PDP-7 small computer; 2. The MINIX operating system is based on a microkernel architecture A UNIX-like computer operating system; 3. The GNU project is a free software collective collaboration project publicly launched by Richard Stallman on September 27, 1983. Its goal is to create a completely free operating system GNU; 4. POSIX standard; 5. Internet network.

#The operating environment of this tutorial: linux7.3 system, Dell G3 computer.

What are the five major factors for the emergence and development of Linux

The birth, development and growth process of the Linux operating system relies on the following five important pillars ：

• UNIX operating system

• MINIX operating system

• GNU Project

• POSIX Standard

• Internet Network

UNIX Operating System

The Linux operating system is a clone of the UNIX operating system. The UNIX operating system is a time-sharing operating system developed on the DEC PDP-7 minicomputer in the summer of 1969 by Ken. Thompson and Dennis Ritchie of Bell Labs in the United States. In order to run his favorite Space Travel game on the unused PDP-7 computer, Ken Thompson developed the UNIX operating system within a month while taking his wife back to his hometown of California for vacation in the summer of 1969. Prototype of the system. The BCPL language (Basic Combinational Programming Language) was used at that time, and was later rewritten in the highly portable C language by Dennis Ritchie in 1972, which made the UNIX system popular in colleges and universities.

MINIX Operating System

Minix is ​​a UNIX-like computer operating system based on microkernel architecture. It was released in 1987 by Professor Andrew S. Tanenbaum. It inspired Linux.

AST works in the mathematics and computer science system of Vrije University in Amsterdam, the Netherlands. It is a senior member of ACM and IEEE (only a few people in the world are senior members of the two conferences). MINIX was compiled by him in 1987 and is mainly used for students to learn operating system principles. By 1991 the version was 1.5. There are currently two main versions in use: version 1.5 and version 2.0. Of course, the MINIX system is currently free and can be downloaded from many FTPs.

Regarding the Linux system, he later expressed his praise for its developer Linus. However, he believes that the main reason for the development of Linux is that in order to keep MINIX small and allow students to learn it in one semester, he did not accept the expansion requirements for MINIX from many people around the world. Therefore, under this premise, Linus was inspired to write a Linux system. Of course, Linus also happened to seize this good opportunity.

As an operating system, MINIX is not outstanding, but it also provides system source code written in C language and assembly language. For the first time, aspiring programmers or hackers were able to read the operating system's source code. At that time, this source code was a secret that software vendors carefully guarded.

GNU Project

The GNU Project, translated as "The Genuine Project", was publicly launched by Richard Stallman on September 27, 1983. Free Software Collective Project. Its goal is to create a completely free operating system GNU.

The software industry created two tit-for-tat leaders in the 1970s, Bill Gates and Richard M. Stallman from Harvard University. The former announced the arrival of the Copyright era and built the glory of the Microsoft empire; the latter founded the free software system GNU in 1984 and formulated the General Public License (GPL). The success of Linux today is due to GPL agreement.

All free software under the GPL agreement follows Richard M. Stallman's "Copyleft" (non-copyright) principle: that is, free software allows users to freely copy, modify and sell, but any modification of its source code must be public to all users.

The GNU Project and the Free Software Foundation FSF (the Free Software Foundation) were founded by Richard M. Stallman in 1984. Aims to develop a complete operating system that is similar to UNIX and is free software: the GNU system (GNU is the recursive abbreviation of "GNU's Not Unix", and it is pronounced "guh-NEW").

Various GNU operating systems using Linux as the core are being widely used. Although these systems are often called "Linux", Stallman believes that, strictly speaking, they should be called GNU/Linux systems.

By the early 1990s, the GNU project had developed many high-quality free software, including the famous emacs editing system, bash shell program, gcc series compiler, gdb debugger and so on. These software create a suitable environment for the development of Linux operating systems. This is one of the foundations for the birth of Linux, so many people currently refer to the Linux operating system as the "GNU/Linux" operating system.

POSIX standard

POSIX (Portable Operating System Interface for Computing Systems) is a cluster of standards developed by IEEE and ISO/IEC. This standard is based on existing UNIX practices and experiences and describes the operating system's call service interface. Used to ensure that compiled applications can be ported and run on multiple operating systems at the source code level. It is based on the early work of a UNIX user group (usr/group) in the early 1980s. The UNIX User Group originally attempted to reconcile the differences between the calling interfaces of AT&T's System V operating system and BerkeleyCSRG's BSD operating system. And in 1984, the /usr/group standard was customized.

About the POSIX standard formulation process: omitted.

In the early 1990s, the formulation of the POSIX standard was in the final stage of voting, which was between 1991 and 1993. At this time, Linux was just getting started. This UNIX standard provided extremely important information for Linux, allowing Linux to be developed under the guidance of the standard and compatible with most UNIX operating systems. In the initial Linux kernel source code (version 0.01, version 0.11), preparations have been made for the compatibility of the Linux system with the POSIX standard. Several symbolic constants related to POSXI standard requirements have been defined in the /include/unistd.h file of the Linux 0.01 kernel, and Linus has written in the comment: "OK, this may be a joke, but I am working on it. It".

Internet Network

Internet is an information and resource exchange platform for Linux development, communication, and development.

Extended knowledge: Comparison between Linux and Unix

The differences we discuss are only discussed in terms of hardware support, copyright and price. The difference between the .

Linux is an operating system that has the same appearance and performance as or better than UNIX, but Linux does not originate from the source code of any version of UNIX. It is not UNIX, but a product similar to UNIX.

Linux is free software that develops source code, and UNIX is traditional commercial software that implements intellectual property protection for source code.

Most UNIX systems are matched with hardware, while Linux can run on a variety of hardware platforms.

UNIX is commercial software and requires a fee; Linux is free software, free, and open source code

In terms of hardware requirements, Linux is lower than Unix and not as demanding as Unix. Linux is easier to master than unix when it comes to installation.

Related recommendations: "Linux Video Tutorial"

The above is the detailed content of What are the five major factors that led to the emergence and development of Linux?. For more information, please follow other related articles on the PHP Chinese website!