What is unix?

The first Unix system was developed by Ken Thompson at AT&T Bell Labs in Murray Hill, New Jersey, United States, starting in 1965. Ken Thompson's purpose was to develop a simple interactive operating system called " Multics ”(Multiplexed Information and Computing System) to be able to use a game he had created (Space Travel, a simulation of the solar system).

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With the start of this project, a consortium consisting of MIT (Massassuchetts Institute of Technology), General Electric Co. and Bell Labs was formed around Multics.

But in April 1969, the Bell and AT&T laboratories decided to use the GECOS (General Electric Comprehensive Operating System) instead of Multics.

Also, Ken Thompson and Dennis Ritchie joined the team and had a need to run the Space Travel game on a smaller machine (a DEC PDP - PDP-7, Programmed Data Processor that only has 4K memory to run the programs. of the users). This is the reason why they recreated the system in order to create a reduced version of Multics called UNICS (UNiplexed Information and Computing Service).

In this way, with the reduced version of UNICS, January 1, 1970 is considered the official date on which the Unix system was born, and it makes clear why all Unix watches start from this date.

Parallel to these activities, D. Ritchie participated extensively in the definition of the C language (since he is considered to be one of the inventors with BW Kernighan), so the whole system was completely rewritten in C language in 1973 and baptized Unix Time-Sharing System (TSS).

When the system went to version 7 in 1979, evolution was accompanied by numerous notable modifications such as:

- The elimination of the problem related to the size of the files

- Better system mobility (operation on numerous material platforms)

- The addition of numerous utilities

A decree dating back to 1956 prevented the company AT&T, on which Bell Labs depended, from marketing anything other than telegraphic or telephone equipment, which is why the decision to distribute Unix fonts to universities for educational purposes It was taken in 1973.

Beginning in late 1977, a group of researchers from the University of California developed a version of Unix from sources provided by AT&T to run the system on its VAX platforms and named it BSD (Berkeley Software Distribution)..

Thus, the two branches of distribution of the sources were moved to:

- The branch of AT&T that was to become System V of UNIX System Labs (USL)

- BSD (Berkeley Software Distribution) developed by the University of California

In 1977 AT&T made Unix fonts available to other companies, so a large number of UNIX-like were developed:

AIX: Commercial Unix based on System V, developed in February 1990 by IBMHP-UX: Commercial Unix based on BSD, created since 1986 by Hewlett Packard Sun Solaris: Commercial Unix BSD developed by Sun Microsystems and based on System VIRIX: Commercial Unix created by SGIUltrix: Commercial Unix developed by DECUnixware: Commercial Unix developed by NovellUnix from SCO: Commercial Unix based on System V, developed from 1979 by Santa Cruz Operations and Hewlett PackardTru64 UNIX: This Compaq Unix was created through Compaq

In 1983 AT&T had the right to commercialize its Unix, fact that originated the appearance of UNIX System V, the commercial version of the Unix system.

Linus Torvalds Linux creator

In 1985 Andrew Tannenbaum, a Dutch teacher, created a minimal operating system, dubbed " Minix ", in order to teach the system programming to his students. In 1991, Linus Tovarlds, a student from Finland, decided to conceive, based on the Minix model, an operating system with the possibility of operating on 386 type architectures. He named this operating system " Linux ".

Most operating systems can be grouped into two different families. One of them is the Microsoft operating systems that were based on Windows NT, the other (almost all the rest) has a Unix-centric heritage.

In this last family, we have Linux, Mac OS X, Android, iOS, Chrome OS, Orbis and even the firmware installed on your modem or router. All of these, and possibly a few thousand more, are often called "Unix-like" operating systems.

From its first versions, Unix already brought some important structure and design attributes that live to this day in its variants.

One of them is the "Unix philosophy" in creating small and modular utilities. If you are familiar with the Linux terminal, this should be familiar to you. The system itself offers a number of utilities that can be combined in different ways to perform more complex tasks on the system.

On Unix there is also a very useful file structure system, which could be used by programs and their file connections. That phrase and the well-known linked to Linux where "everything is a file", is a true inheritance from Unix. This includes special files and hardware devices that provide information about the operating system. Looking at the other side, only Windows names its drives with letters, a fact completely inherited from DOS systems.

The Unix Timeline

In truth, GNU / Linux is not a direct descendant of BSD, but it is a descendant of a Unix project that had its roots in schools and universities in the United States. Many current operating systems, such as Android, Chrome OS, and a host of other operating systems are GNU / Linux based.

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On the other hand, there was a market to be explored with a view to the future of Unix. Large corporations wanted to create and license their own Unix to market their home versions. Among these large corporations were SCO UnixWare, Novell with its wonderful NetWare, Sun with Solaris, HP-UX, IBM AIX, SGI IRIX and many others. A fact that many do not know is that even Microsoft entered the joke of creating their own Unix-like with Microsoft Xenix.

All this history clearly shows that Microsoft has not started a project from scratch when developing its system. Today all Microsoft operating systems are based on the Windows NT kernel. We have Windows 7, Windows 8, Windows RT, Windows Phone 8, Windows Server and the Xbox operating system, which use a Windows NT kernel that was designed to maintain compatibility with older programs by inheriting a lot from MSDOS.

The Unix standard

Given the large number of Unix systems created based on AT&T System V or BSD, the question of a Unix standard was put into the / etc / group discussion group from 1981 in order to guarantee maximum mobility between systems:

In 1983, AT&T publishes SVID (System V Interface Definition) that describes System V. This first definition is different from POSIX In 1984 the / etc / group publishes POSIX, a series of standards developed under the IEEE (Institute of Electrical and Electronics Engineers). POSIX is thus also known under the name of IEEE P1003. At the same time, a consortium of builders (Sun, IBM, HP, DEC, AT&T, Unisys and ICL) publishes the X / Open Portable Guide Issue3 (XPG3) standard. This standard particularly refers to the preceding differences in geographic location (date, alphabet, etc.).

Why was Unix and is it important?

Have you taken a look at the Mac OS X terminal or the structure of your file system? Mac and Linux are Unix-like operating systems. Knowing a bit about all this history, it helps to better understand what a “Unix-like” operating system is, and why so many existing operating systems on the market are so similar to each other, while Windows looks so different from the others.. This explains why when using the terminal in Mac OS X, you will feel more comfortable in case you are a Linux user.

We recommend the best Linux distributions and light distributions that currently exist.

The Unix system is a multi-user, multi-tasking operating system, which means that a single or multi-processor computer is allowed to run multiple programs simultaneously by one or more users. It has one or more shell interpreters, as well as a large number of commands and numerous utilities. It also has great mobility, which means that it is possible to install a Unix system on almost all platforms.