The Unix operating system is wonderful. GNU/Linux is wonderful. Let me make this distinction, before discussing the aforementioned three tools: GNU is Not Unix. This is a story of how capitalism limits the human spirit, in order to extract financial gain.
Before writing about the remarkable tools provided by Unix---and now, the GNU computing system (one of the scions of which is GNU/Linux)---one may be forgiven for visiting certain concerns, including the generation of incomprehensible wealth by a few men who now seek to control our lives in ever more of their detail. I suggest that this wealth was made primarily through marketing, on the backs of the ingenuity of other men, some of whom were out-maneuvered and left behind by certain well known business men.
It came about, during the early days of computing, long ago: a gifted programmer by the name of Richard Stallman worked at MIT Artificial Intelligence Laboratory (MITAIL), along with other highly capable computer programmers. Events during that period led to unforeseeable changes, as a behemoth technical-industrial complex grew beyond all imagination, based on deft slight-of-hand and shrewd business moves, as entrepreneurs snatched up computer code, patented and copyrighted it, and concealed it from hapless consumers. Shrewd manipulations of programmers and code enabled a few men, in less than 50 years, to accumulate over half of the wealth of the financial world.
This they were able to do by convincing consumers not to share, with the complicity of the legal "intellectual property" infrastructure; to violate the golden rule that many had cherished since childhood. Make many copies of a useful computer program for a few pennies each, and set prices arbitrarily high. The consumer will be so mesmerized by the utility and flashiness of these programs that she will believe you are doing her a favor, selling it so cheap. Convince governments to sign lucrative contracts. Update products at speed, and charge for the updates. Sue public schools when they did not update to newer licenses. the profits would be almost unlimited. And, now, change the business model and lease software, so leverage even greater control, and much greater profits. Never do unto others anything without transactional benefits to self. Above all, do not share a computer program, even though they are useful. This was a massive wealth grab.
Tim Wu has written about the entrepreneurs who built incomprehensible wealth by these same strategies: seize control of the media channels, prevent newcomers by various and nefarious means, and charge arbitrarily high rates for the use of this now valuable commodity: information. Radio. Telegraph, Telephone, and Television have been used to manipulate the public, by employing choke points---selective filters---to manipulate elections, gain power, and sell snake oil. The political landscape has been altered in the interest of gaining more power, prestige, wealth, and control. It's OK, these persons believe, to lie and deceive. Today's politicians have gained success by following a model of radical "gas lighting," and in doing so have built empires of corruption and greed.
You may know this story.
Richard Stallman has been painted under the dark lights of deception as an extremist, even among other adherents to Free Software. This is how the insidious tactics of industry and politics can influence our opinions to their own benefits. The Petroleum Industry, in a similar manner, convinces us that global climate change is a hoax, that CO2 is fine. Our politicians convince us, who are eager to consume their distorted and deceptive messaging, of these things, and many others. We know they are lying, but the steam engines of their corruption are traveling down the tracks with such unrelenting force and momentum that they seemingly have taken over our own minds and hearts.
This is about one little part of the story.
The MITAIL was at the forefront, in those beginning days of computing. Richard Stallman was there; he noticed that the software interface of their very expensive printer was inefficient, klunky. In the hopes of improving this interface, he kindly offered to the company that owned the patents, to tweak the software and make it work better. The manufacturer, however, was unwilling to open up the code behind that software, fearing loss of control and profit if it ware revealed.
This is an important story, but this is not our story today. Suffice it to say that Richard Stallman decided to do an end-around, in the finest traditions of human cooperation and sharing. The Unix Operating System, owned by Bell Laboratories (AT&T), was an outstanding work of programming, a thoughtfully produced system of software, an interface of great utility, with numerous subprograms attached to a central kernel, making a whole that by far exceeded the sum of its parts. But AT& T owned Unix. In the capitalistic world, this was a fantastic money maker. But the cost of ownership was onerous, making it impossible for the average computer user to purchase. And as Stallman had already learned, the impediments that proprietary software posed to even the best programmers presented various difficulties---even beyond simple ownership. The experience with a printer had taught that lesson.
And what about sharing these wonderful tools? Stallman recalled an earlier time when the many talented programmers and users at the MITAIL had freely shared programs they had developed. As a consequence of this open access to the universe of such software programs, even greater programs were spawned from the synergism... But now many of those programmers had been enticed to leave this world by unimaginably lucrative contracts. But these contracts had been concealed within a trojan horse: the non-disclosure agreement. The code, they promised, they would not share. And even the end users, who purchased such programs today as Photoshop, Lightroom, games, typing tutors, graphics printing programs.... ad infinitum, are coerced into not sharing the software they purchase. The industry is serious about this limitation.
So Richard Stallman reached out on the internet to propose a collaboration of programmers to build a new computer system, a free system, that could be "shared without dishonor." Remember how Unix comprises a set of software units that are hook in to a kernel? Those units include various commands: copy and move files, for example. Even typing on a keyboard is handled by tools hooked into the kernel. The construct, from a plethora of these units, is an Operating System (OS). Such operating systems as the proprietary MS-DOS, Windows, and MacOS are example of proprietary OSes. It is forbidden by the proprietors of these OSes to share the programs. At great expense, these companies have constructed elaborate schemes to make it difficult or (they hope) impossible to share these programs.
Do you see where we are going with this? This massive construct, including now Microsoft, Facebook, Apple, Google, Oracle, Adobe, and others, has used a strategy of concealment, of forcing others to not share, to build huge empires, and horde wealth. Intimidating the consumer, for example by suing Portland, Oregon's public schools to force purchase of contracts for every copy of windows that had not been updated, as "required" by the manufacturer.
But GNU is Not Unix. Richard Stallman recognized Unix as a wonderful model for an OS. If thousands of programmers all over the world, connected by the Internet, were to each write one or a small number of utility programs, mirroring those that perform the functions of the Unix programs, while avoiding even any appearance of copying the Unix code, a new operating system could be built up through community action, a citizen-built computing system. This system was successfully built. Even a protracted legal challenge by the owners of Unix, SCO, many years later, could not find any copied code in the GNU/Linux operating system.
When I was isolated in Chuuk Lagoon, I had been conducting research that required access to computers. My family donated a laptop computer, but the Windows OS was clumsy, and, to cut to the chase, could not help me with my project. An editor that had been sent to me by a linguist at the University of Hawaii was capable, but it was "cripple ware," in a sense, and without the manual---which sold separately for hundreds of dollars--I could not proceed.
The Free Software Foundation (FSF) responded to my request for an editor, sending a version of the Emacs editor ported to Windows, along with 14 disks of Unix tools, also that would run on Windows. This was just what I needed. Among these tools were a number of Unix text tools, opening a window into a new world of possibilities. Very important to me were sort, grep, and ptx. These, as far as I am concerned, are core Unix (hence Linux) superpowers.
sort
Windows had a sort utility, but it was extremely limited. In fact, the more I learned of the tools granted to me by the FSF, the better I understood the fraud that had been perpetrated on the public, corporate world, and governments by Microsoft. I can liken the difference between the facilities provided by Unix (and later by Linux and FreeBSD) is comparable to the difference between a set of cheap carpenter's tools, and professional quality tools. GNU sort is the Cadillac of sort programs, the Rolls.
Later, on Guam, I was able to download a copy of the new Linux OS on Guam. It was then that I discovered liberation. From that day, in the early 1990s, until today, in 2025, I never never felt comfortable on a Windows computer. At that time, one of the biggest differences was that Linux was capable of doing true multitasking, while Windows only could do one operation at a time. With GNU/Linux I could type a letter while printing a different document, and running another process in the background. Another difference was the Linux did not crash. Let me repeat, it never crashed or locked up. Windows regularly did so.
grep
I will not explain grep. Today, in the 2020s, one can run grep on Windows machines. Suffice to say that grep is a tool that enables searching through a set of files for a search term, and printing to the screen a list of matches. With pipes (signified by the character "|", one can direct the output of grep to another program, like sort. Then, from sort, one may direct its output to less, a better file browsing tool than Unix's more, a tool that pages through a file. To do this one would type:
$ grep <filename.txt> | sort | less
ptx
My need was specialized, as I was dealing with lexical text, lists of animal names. To weed through these, I found ptx was incredible. Ptx means "permutated index." What follows is a small segment of output from a search of a text file about flowers and seasons of fishing.
/Luma, altitude 100-125 meters, flower, August 4, 1921, Garber no./
/\section{Burrows: a different flower, and palolo.\hfill{}\textsc/
specifically, he does mention a flower.
with certain things. There is a flower called bust ginger;/ /time
\textit{Erythrina\/} sp. as an indicator species. /about
/constellation as a seasonal indicator, he refers to this/
a resident of Wonipw,/ This indicator would only be useful to
the/ /solar alignment as a key indicator of the emergence of
/\hfill{}\textsc{whale:season: indicator}} \label{sec:org5e260c7}/
/tree fruits are ripe, it is an indicator that whales are running/
Samoa/ /was used as a seasonal indicator on some islands (e.g.,
/2015, Trees of Yap: sometimes indicator of seasons} \label{sec:/
. \textbf{Sometimes used as an indicator of season.} /flowers
a resident of Wonipw,/ This indicator would only be useful to
/variegata\/} flowers in the dry season, and has been mentioned (/
and that it flowers during dry season. /of year of flowering,
/these two periods the iéboua season; the \%\% season of the/
/the iéboua season; the \%\% season of the sun or heat iéboua-/
/or heat iéboua-délat, and the season of cold iéboua-tsiam.
tldr
Tldr (too long didn't read) is a modern innovation that summarizes the man page for a command. In Unix, it was specified that who ever wrote a program must provide a "man": page, a manual to its use and options. Here is output from tldr:
$ tldr ptx
Generate a permuted index of words from text files.
More information: <https://www.gnu.org/software/coreutils/manual/html_node/ptx-invocation.html>.
Generate a permuted index where the first field of each line is an index reference:
ptx --references path/to/file
Generate a permuted index with automatically generated index references:
ptx --auto-reference path/to/file
Generate a permuted index with a fixed width:
ptx --width=width_in_columns path/to/file
Generate a permuted index with a list of filtered words:
ptx --only-file=path/to/filter path/to/file
Generate a permuted index with SYSV-style behaviors:
ptx --traditional path/to/file
