Unix, the first operating system written in the C language

Unix is ​​an operating system written in the C programming language. Its variants, notably Linux and Minix, are widely used in the world of computing. However, the current trend could lead to its abandonment, although the precise moment has not been defined.

The operating systems found today on some mobile devices, embedded devices, and even some computers are actually descendants of a single system called Unix. In factmacOS, iOS, Android And, especially Linux come from the same family. The other family, you already know, Windows-NT is the Microsoft product. In this file we will focus on Unix and everything there is to know about it. Focus!

What is Unix?

Unix is ​​an operating system developed in the 1970s by Bell Laboratories (later AT&T Labs). It is the first system written in C programming language. The system was started by two software developers, Ken Thompson and Dennis Ritchie.

His success was first in the gym. One of the institutions that adopted Unix is ​​the University of California, Berkeley. A work that would later lead to a variant of the system called Berkeley Software Development or BSD. BSD, in turn, inspired the design of other variants such as FreeBSD, OpenBSD and NetBSD.

The system used by the PlayStation console is inspired by BSD code. As for Unix, it will be supplanted by Linux, one of his descendants. This is an open source system, which gives it a wide range of use in today’s IT environment. The most popular are Ubuntu and Fedora. Furthermore, the cloud platformsmostly I’WordPress Hosting use Linux.

For the little story

After the abandonment of Multics Project, an interactive time-sharing system, Bell, the two developers Thompson and Ritchie decided to continue the project. By collaborating with other researchers, the work built a set of components that would serve as the basis for the future Unix. The suite included a command line interface (CLI), a hierarchical file system, and small utility programs.

At first, the system was a smaller single-task system than Bell Labs planned for the Multics project. Only later did he acquire his multitasking skills. The C programming language was, at the time, considered high-level. This, in turn, propelled Unix to many platforms.

The beginning of the 1980s was marked by the great success of Unix in the academy before start-ups like Solaris Technologies and Sequent adopted it. In addition to UC Berkeley’s BSD, another Unix-like system was developed by a young student at the University of Helsinki for his own PC. It is the ancestor of current Linux. Today, many Unix operating systems are found on embedded devices, macOS computers, and mobile devices.

Unix components

The Unix system is made up of three essential elements: the kernel, the shell and the file system. In this part we will develop each component.

The core

As the name suggests, the nucleus is the operating system center. Its function is to provide the necessary applications to ensure communication between the device, the operating system and the installed applications.

Here, in summary, are the main functions of the kernel:

  • Manage main memory;
  • Plan tasks;
  • Manage data transfers;
  • Applies access permissions;
  • Accepts shell commands before executing them.

The shell

That’s it the interface between the kernel and the user who operates the system. The shell is a command-line interface (CLI) that provides a platform or environment with which users can execute commands and scripts. To do this, the shell receives commands and passes them to the kernel to be interpreted and executed.

The main tasks of the shell can be summarized as follows:

  • Execution of commands and scripts;
  • Control automatic completion using the TAB key on the keyboard;
  • Displaying commands that have already been executed. The shell has a list containing all the commands a user has executed.

In Unix, there are 2 main shells called Bourne Shell and C Shell. In addition to these, there are also projectile variations, including Bourne Again Shell and Korn Shell.

fs or Unix file system

In Unix, there is a system designed to organize and store a considerable amount of data in order to facilitate its conservationand possibly your recovery. This system is called the file system or fs for short. To do this, the system organizes data into small units, files. Storage is done by opting for a hierarchical directory structure.

Types of files existing on a Unix system

As we saw above, data in Unix is ​​organized into small units called files. To facilitate organization and retrieval, files are divided into different types, including normal files, symbolic links, and special folders.

Common files

Common files are those that users interact normally daily. They include text, images and videos, as well as instructions. In the directory, these files are preceded by a hyphen (–).

Symbolic links

Some files stored in Unix do reference to other files. They are special files, also called symbolic links or parameterized links. These files contain text that contains the path to the file they refer to.

Special files

All files included in “/dev” directory They are called special files. They indicate physical devices i.e. disk drive, CD-ROMs, printer, etc. In Unix they are used for input and output operations.

Unix Features

The main characteristics of Unix are summarized in its most important features. However, it is important to emphasize that the fact that it is first system written in C language differentiates it from other operating systems. Additionally, its hierarchical file structure simplifies data access and maintenance.

In terms of functionality, Unix is ​​primarily an operating system multi user. In this system, users can share resources and exchange information between them. Then it allows its user to multitask. In fact, in Unix you can run multiple processes at the same time. Additionally, it is possible to expand the system using user programs created in a standard programming interface.

Unix variants

Everyone can improve Unix due to the fact that it is written in the high-level C language and its great popularity. This is also the reason why we quickly find multiple variants. However, these lack interoperability and compatibility. Faced with such constraints, some industry participants standardized the system with the standard Portable Operating System Interface first, then the single Unix specification or SUS.

Since then, new variants have emerged, some of which the Owners while others open code. Proprietary Unix variants, such as Oracle Solaris and IBM Advanced Interactive eXecutive (AIX), come with licensing fees. On the other hand, there are free and open source variants like FreeBSD, OpenBSD and Linux. Today, Unix is ​​part of an industry standards body, The Open Group, which certifies and marks its implementations.

Unix-like systems

You’ve probably heard the term Unix-like which is used most often when talking about Unix variants. It is, however, vague because any operating system that has some relation to Unix can be described as such. For some software developers, there are only 3 types of Unix systems.

The first type brings together all operating systems connected to the base original code from Belle Labs. The systems invented by researchers at the University of Berkeley belong to this first type.

Unix-like and trademarked systems meeting SUS criteria like IBM AIX and HP-UX belong to the second type. These can, according to The Open Group, use the Unix name. The last type of Unix system includes functional systems like Linux and Minix. They behave according to the basic specification.

What would the future of Unix look like?

Many servers, workstations and even supercomputers run on Unix and its variants. One of these variants, Linux remains at the center of Data Center It is Cloud computing. Furthermore, we count 500 supercomputers who use it all over the world.

However, migration to x86 alternatives, due to its power and reduced cost, caused a decline in the use of Unix. In this way, sales will certainly gradually decrease until the system is completely removed from the market. It still takes a long time for this to actually happen.

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