The three most popular operating systems in the world are Windows, Mac and Linux. These three operating systems are getting all the press, the first two are more than the second, and are probably the only ones you’ve heard of yourself.
What if I told you that two of the three most popular operating systems actually include the underlying philosophy of something called UNIX? These principles are the basic concepts of a time-sharing system that allows multiple users to access the same mainframe at the same time.
Designed back in 1970 and conceived as a small, flexible system used exclusively by programmers, UNIX quickly became the leading operating system for workstations. But what do you really know about UNIX?
HDG Explains: What is UNIX?
UNIX and UNIX-like operating systems are the most powerful and popular multiuser and multitasking operating systems on the market. Several generations of UNIX have been developed over the years for various machines, including modern POSIX systems such as Linux, its many flavors, and the Mac OS. It’s hard to believe that something so powerful could have such a humble beginning.
UNIX was developed at Bell Telephone Laboratories or Bell Labs by a handful of C programmers. This allowed it to be installed on almost any computer with a C compiler. This alone gave UNIX natural portability, flexibility, and a rather powerful option as an operating system.
Bell Labs was not only inexpensive, but distributed the operating system in its original language form, allowing anyone who got it to modify and customize it for their own purposes. This has spawned dozens of different versions of UNIX over ten years running on different sites.
Bell Labs eventually disbanded in 1984. However, they started selling UNIX in an attempt to define a standard version of the system. They developed something that many felt was too restrictive, one of them was Richard Stallman, the GNU project manager. The GNU Project is the basis for the Linux that we know today because it is made up of the Linux kernel, not the UNIX kernel.
However, Linux was inspired by MINIX, a UNIX-like operating system built for educational purposes. This led to a kind of domino effect for most operating systems available today. GNU / Linux evolved from the UNIX design, and in turn, many operating systems today, including Android, Chrome OS, Steam OS, and a huge number of embedded operating systems for devices, are based on Linux.
The standard did appear, but AT&T was not based on anything. Today the UNIX trademark is owned by the Open Group. The same can be said for the uniform UNIX specification. Any operating system that uses UNIX must be certified by the Open Group and comply with the Uniform UNIX Specification.
As The Open Group shows:
For anyone interested in following the link in the image, here it is
POSIX, as mentioned earlier, is a family of standards defined by the Institute of Electrical and Electronic Engineers (IEEE) They serve to clarify and unify the APIs provided by UNIX-like operating systems.
Because of this, when you write a program based on POSIX standards, portability and functionality becomes lightweight among the large family of UNIX derivatives such as Linux and Mac OS. Using an API or code not standardized as part of POSIX for UNIX-like operating systems will make portability to other UNIX-like systems much more difficult.
What are UNIX programs, systems, and subsystems?
What are UNIX programs, systems and systems?
UNIX commands are executed in the command line interface provided by the shell. This shell is a program that will read the commands entered and either execute them or pass them to the kernel.
The “kernel kernel” is what UNIX systems are built on, which controls the system and other processes. It is the core of the UNIX operating system that interacts directly with the underlying hardware to provide a set of standard services. Kernel subsystems can include process management, file management, memory management, network management, and others.
UNIX programs are designed around several basic philosophies, including requirements such as a single purpose, interoperability, and a standardized text-based interface.
As far as UNIX functions are concerned, here is a list of some of them:
- Allows you to use the same resources for different users on the same system.
- Provides multitasking in which each user can run many processes at the same time.
- The first operating system written in a high-level language to simplify porting to other machines with minimal adaptation.
- A hierarchical file structure that simplifies data access and maintenance.
- Built-in networking functions for easy exchange of information between users.
Why is UNIX important
Apart from Windows and Windows-based systems, most of the operating systems that you will see have a UNIX-based philosophy. If you look at the Mac OS X terminal or file system, you will notice a striking resemblance to Linux. Both are completely different from Windows. This is because Linux and Mac OS are UNIX-like systems.
Understanding this will also help you understand how important and was important UNIX. One of the main UNIX philosophies in use today is to create small, modular utilities to perform specific tasks with exceptional efficiency. Getting familiar with the Mac OS terminal will also introduce you to the Linux terminal and vice versa. In short, this is UNIX.
UNIX-like systems rely on a single file system for programs to communicate with each other. Windows-like systems rely on DOS. This is the reason that only Windows-like systems have drive letters. In all other operating systems, every file on the system is part of a single directory hierarchy. Again, all thanks to the UNIX philosophy.
UNIX can be seen in the architecture of operating systems such as BSD, Linux and Mac OS, entirely by design. We could say that without UNIX there would be no Mac OS, and quite possibly the same could be said of its competitors, including Windows.
Here we are clearly exaggerating. However, you must admit that UNIX has played an important role in the development of every operating system in use today. If that doesn’t illustrate the importance of UNIX and its philosophy, I’m not sure what will happen.