Unix is a multi-user, multi-process computer operating system that supports multiple processor architectures. According to the classification of operating systems, it is a time-sharing operating system; in addition to being a network operating system, Unix can also Used as a stand-alone operating system. The UNIX system provides a good user interface, which is easy to use, fully functional, clear and flexible, and easy to expand and modify.
#The operating environment of this article: Windows 7 system, UNIX V6 version, Dell G3 computer.
unix is a multi-user, multi-process computer operating system. It is a powerful multi-user, multi-task operating system that supports multiple processor architectures. According to the classification of operating systems , a time-sharing operating system, was first developed at AT&T's Bell Labs in 1969 by Ken Thompson, Dennis Ritchie, and Douglas McIlroy.
In addition to being a network operating system, Unix can also be used as a stand-alone operating system. Unix is widely used as a development platform and desktop operating system, mainly in engineering applications and scientific computing.
Currently its trademark rights are owned by the International Open Standards Organization. Only UNIX systems that match a single UNIX specification can use the name UNIX, otherwise it can only be called UNIX-like (UNIX-like).
History of unix
In 1965, Bell Labs joined a project led by General Electric ) and the Massachusetts Institute of Technology (MIT); the plan is to build a multi-user, multi-tasking, multi-level (multi-user, multi-processor, multi-level) MULTICS operating system.
Until 1969, the MULTICS project was stopped because the work progress was too slow. At that time, Ken Thompson (later known as the father of UNIX) already had a program called "Star Trek" running on the GE-635 machine.
But the response was very slow. He happened to find an idle PDP-7 (Digital's host). Ken Thompson and Dernis Ritchie transplanted the "Star Trek" program to the PDP-7.
Characteristics of UNIX system
The UNIX system occupies an important position in the history of the development of computer operating systems. It has indeed continued to meticulously, carefully and selectively inherit and transform existing technologies, and has made some progress in the overall design concept of the operating system, which has made it such a great success. The main characteristics of the UNIX system are reflected in the following aspects:
1. The UNIX system is structurally divided into two parts: the core program (kernel) and the peripheral program (shell), and the two are organically combined into a whole. The core part is responsible for the functions of each module within the system, namely processor and process management, storage management, device management and file system. The core program is characterized by careful design, conciseness and leanness. It only takes up a small space and is resident in the memory to ensure the high efficiency of the system. The peripheral part includes the system's user interface, system utilities and applications, through which users use the computer.
#2. The UNIX system provides a good user interface, which is easy to use, fully functional, clear and flexible, and easy to expand and modify. There are two forms of use of the UNIX system: one is the operating command, that is, the shell language, which is the interface through which users can interact with the system through the terminal; the other is the interface for user programs, which is not only in assembly language, but also in Provide services to users in C language.
3. The file system of UNIX system is a tree structure. It consists of a basic file system and several removable sub-file systems, which can not only expand file storage space, but also facilitate security and confidentiality.
4. The UNIX system handles files, file directories and devices in a unified manner. It treats files as character streams without any records for sequential or random access, and enables files, file directories and devices to have the same syntax and semantics and the same protection mechanism, which not only simplifies the system design, but also facilitates user use.
5. The UNIX system contains a very rich set of language processing programs, utilities and tool software for software development, providing users with a fairly complete software development environment.
6. Most of the programs in the UNIX system are programmed in C language, and only about 5% of the programs are programmed in assembly language. C language is a high-level programming language, which makes UNIX systems easy to understand, modify and expand, and has very good portability.
7. The UNIX system also provides simple communication functions between processes.
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