All Unix, Linux and other Unix-like operating systems are families of computer operating
systems derived from the original Unix System from Bell Telephone
Laboratories. Today, the largest Unix descendent directly certified as
"UNIX" is macOS by Apple. The original commercial Unix derivatives included
HP-UX, AIX and SunOS, to name a few. The diversity and perceived
incompatibility between various Unix systems led to the creation of
interoperability standards including the Portable Operating System Interface
Unix is the original and most powerful and popular multi-user and
multi-tasking Operating System. The basic concepts of Unix were originated
in the Multics project of 1969. The Multics system was intended as a
time-sharing system that would allow multiple users to simultaneously access
a mainframe computer. Ken Thompson, Dennis Ritchie, and others developed the
basic building blocks of Unix including a hierarchical file system and a
command line interpreter for the PDP-7. Multiple generations of Unix systems
were developed for myriad computers.
As mentioned, historical perceived incompatibility between the various early
Unix systems led to the creation of POSIX and the Single Unix Specification.
Historically, the rigid "standardization" approach led to the creation of
various open source approaches to Unix including the Free Software
Foundation (FSF), GNU and Linux. Unix programs were originally created
around core design philosophies that included requirements like single
purpose, interoperable, and working with a simple standardized text
interface. Unix systems are built around a core kernel that manages the
system and the other processes. Kernel subsystems may include process
management, file management, memory management, network management and
Unix is a multi-user system where the resources can be shared by various
Unix provides multi-tasking. Users can execute many processes at
the same time (practically speaking).
Unix was the first computer operating system that was written in a
high-level language (C Language).
Unix provides a hierarchical file structure which facilitated fast data
Unix has built-in networking functions so that computers can easily exchange
Unix functionality can be extended through user programs built on a
standard programming interface.
UNIX certifies compliance with a full set of interoperability standard, managed and maintained by the Open Group, which includes, not only the kernel, but the entire operating system.
What is Linux?
Linux is a Unix-like operating system created by Linus Torvalds at the
University of Helsinki in 1991. The name Linux refers to
the Linux kernel, the software on a computer which permits applications and
users to access the devices on the computer to perform specific
functions. The development of Linux was a landmark example of global, free
and open source software collaboration. Many companies and similar numbers
of individuals have released their own version of Unix-like operating
systems based on the Linux Kernel.
Similar to Unix kernels, the Linux kernel relays instructions from an
application from the computer's processor and sends the results back to the
Broader in scope than commercial Unix products, Linux has been installed on a variety of platforms including mobile phones, tablets, video game consoles, NAS storage arrays, routers and small embedded controllers.
Currently the world's largest and most powerful data centers and scientific
research centers use some "flavor" of Linux.
The development of Linux is a stellar example of the power of free and open
source software development and global human collaboration.
A Linux "distribution" is a release of a Unix-like operating system based on
the specifications of the Linux kernel.
Linux, like Unix, is a multi-user
system where the resources can be shared by various system users.
Linux, like Unix, provides
multi-tasking. Users can execute many processes at the same time
Linux, like Unix, was written in C.
Linux, like Unix, provides a
hierarchical file structure which facilitated fast data access.
Linux, like Unix, has built-in
networking functions so that computers can easily exchange information.
Linux, unlike UNIX, specifies only the kernel but
not the entire operating system.
Please Contact Us in the "Contact Us" Forums if You Have Any Questions or Comments.
An Interest Fact about the History of Unix and Linux
sed (stream editor)
sed (stream editor) is a Unix utility that parses and transforms text using a simple and compact programming language.
sed was developed from 1973 to 1974 by Lee E. McMahon of Bell Labs and is available today for most Unix-like operating systems.
sed was based on the scripting features of the interactive editor ed ("editor", 1971) and the earlier qed ("quick editor", 1965–66).
sed was one of the first Unix tools to support regular expressions and remains in use for text processing, most notably with the substitution command.
Popular alternative tools for plaintext string manipulation and "stream editing" include AWK and Perl.
sed first appeared in Version 7 Unix and is one of the original Unix commands built for command line processing of data files.
sed evolved as the natural successor to grep. The original motivation for sed was an analogue of grep (g/re/p) for substitution, hence "g/re/s".
Realizing that additional special-purpose programs for each command would also arise, such as g/re/d, McMahon wrote a sed as a general-purpose line-oriented stream editor.
The syntax for sed, notably the use of / for pattern matching, and s/// for substitution, originated with ed, the precursor to sed.
The regular expression syntax from ed and sed influenced other languages, notably ECMAScript and Perl.
Later, the more powerful programming language AWK was developed allowing powerful text processing to be done by shell scripts. sed and AWK are often cited as the ancestors and inspiration for Perl. sed and AWK influenced Perl's syntax and semantics, especially in the matching and substitution operators.
Please enjoy and help our forum community by "showing your work" and
posting your code, even when your code is not working as expected. To
help others help you, please wrap your code blocks, sample input,
sample output, error messages, and other data in
CODE tags and wrap your short
commands and short data objects in
ICODE tags. We were all beginners
in the beginning. If you have any questions about how to register or
how to post, please contact us in
our forum for unregistered users.. Thank you and enjoy this "forever free" technical support community
for UNIX, Linux and computer information technology in general.