The Unix Koans of Master Foo

Master Foo and the Ten Thousand Lines

Master Foo once said to a visiting programmer: “There is more Unix-nature in one line of shell script than there is in ten thousand lines of C.”

The programmer, who was very proud of his mastery of C, said: “How can this be? C is the language in which the very kernel of Unix is implemented!”

Master Foo replied: “That is so. Nevertheless, there is more Unix-nature in one line of shell script than there is in ten thousand lines of C.”

The programmer grew distressed. “But through the C language we experience the enlightenment of the Patriarch Ritchie! We become as one with the operating system and the machine, reaping matchless performance!”

Master Foo replied: “All that you say is true. But there is still more Unix-nature in one line of shell script than there is in ten thousand lines of C.”

The programmer scoffed at Master Foo and rose to depart. But Master Foo nodded to his student Nubi, who wrote a line of shell script on a nearby whiteboard, and said: “Master programmer, consider this pipeline. Implemented in pure C, would it not span ten thousand lines?”

The programmer muttered through his beard, contemplating what Nubi had written. Finally he agreed that it was so.

“And how many hours would you require to implement and debug that C program?” asked Nubi.

“Many,” admitted the visiting programmer. “But only a fool would spend the time to do that when so many more worthy tasks await him.”

“And who better understands the Unix-nature?” Master Foo asked. “Is it he who writes the ten thousand lines, or he who, perceiving the emptiness of the task, gains merit by not coding?”

Upon hearing this, the programmer was enlightened.

Master Foo and the Script Kiddie

A stranger from the land of Woot came to Master Foo as he was eating the morning meal with his students.

“I hear y00 are very l33t,” he said. “Pl33z teach m3 all y00 know.”

Master Foo's students looked at each other, confused by the stranger's barbarous language. Master Foo just smiled and replied: “You wish to learn the Way of Unix?”

“I want to b3 a wizard hax0r,” the stranger replied, “and 0wn ever3one's b0xen.”

“I do not teach that Way,” replied Master Foo.

The stranger grew agitated. “D00d, y00 r nothing but a p0ser,” he said. “If y00 n00 anything, y00 wud t33ch m3.”

“There is a path,” said Master Foo, “that might bring you to wisdom.” The master scribbled an IP address on a piece of paper. “Cracking this box should pose you little difficulty, as its guardians are incompetent. Return and tell me what you find.”

The stranger bowed and left. Master Foo finished his meal.

Days passed, then months. The stranger was forgotten.

Years later, the stranger from the land of Woot returned.

“Damn you!” he said, “I cracked that box, and it was easy like you said. But I got busted by the FBI and thrown in jail.”

“Good,” said Master Foo. “You are ready for the next lesson.” He scribbled an IP address on another piece of paper and handed it to the stranger.

“Are you crazy?” the stranger yelled. “After what I've been through, I'm never going to break into a computer again!”

Master Foo smiled. “Here,” he said, “is the beginning of wisdom.”

On hearing this, the stranger was enlightened.

Master Foo Discourses on the Two Paths

Master Foo instructed his students:

“There is a line of dharma teaching, exemplified by the Patriarch McIlroy's mantra ‘Do one thing well’, which emphasizes that software partakes of the Unix way when it has simple and consistent behavior, with properties that can be readily modeled by the mind of the user and used by other programs.”

“But there is another line of dharma teaching, exemplified by the Patriarch Thompson's great mantra ‘When in doubt, use brute force’, and various sutras on the value of getting 90% of cases right now, rather than 100% later, which emphasizes robustness and simplicity of implementation.”

“Now tell me: which programs have the Unix nature?”

After a silence, Nubi observed:

“Master, these teachings may conflict.”

“A simple implementation is likely to lack logic for edge cases, such as resource exhaustion, or failure to close a race window, or a timeout during an uncompleted transaction.”

“When such edge cases occur, the behavior of the software will become irregular and difficult. Surely this is not the Way of Unix?”

Master Foo nodded in agreement.

“On the other hand, it is well known that fancy algorithms are brittle. Further, each attempt to cover an edge case tends to interact with both the program's central algorithms and the code covering other edge cases.”

“Thus, attempts to cover all edge cases in advance, guaranteeing ‘simplicity of description’, may in fact produce code that is overcomplicated and brittle or which, plagued by bugs, never ships at all. Surely this is not the Way of Unix?”

Master Foo nodded in agreement.

“What, then, is the proper dharma path?” asked Nubi.

The master spoke:

“When the eagle flies, does it forget that its feet have touched the ground? When the tiger lands upon its prey, does it forget its moment in the air? Three pounds of VAX!”

On hearing this, Nubi was enlightened.

Master Foo and the Methodologist

When Master Foo and his student Nubi journeyed among the sacred sites, it was the Master's custom in the evenings to offer public instruction to Unix neophytes of the towns and villages in which they stopped for the night.

On one such occasion, a methodologist was among those who gathered to listen.

“If you do not repeatedly profile your code for hot spots while tuning, you will be like a fisherman who casts his net in an empty lake,” said Master Foo.

“Is it not, then, also true,” said the methodology consultant, “that if you do not continually measure your productivity while managing resources, you will be like a fisherman who casts his net in an empty lake?”

“I once came upon a fisherman who just at that moment let his net fall in the lake on which his boat was floating,” said Master Foo. “He scrabbled around in the bottom of his boat for quite a while looking for it.”

“But,” said the methodologist, “if he had dropped his net in the lake, why was he looking in the boat?”

“Because he could not swim,” replied Master Foo.

Upon hearing this, the methodologist was enlightened.

Master Foo Discourses on the Graphical User Interface

One evening, Master Foo and Nubi attended a gathering of programmers who had met to learn from each other. One of the programmers asked Nubi to what school he and his master belonged. Upon being told they were followers of the Great Way of Unix, the programmer grew scornful.

“The command-line tools of Unix are crude and backward,” he scoffed. “Modern, properly designed operating systems do everything through a graphical user interface.”

Master Foo said nothing, but pointed at the moon. A nearby dog began to bark at the master's hand.

“I don't understand you!” said the programmer.

Master Foo remained silent, and pointed at an image of the Buddha. Then he pointed at a window.

“What are you trying to tell me?” asked the programmer.

Master Foo pointed at the programmer's head. Then he pointed at a rock.

“Why can't you make yourself clear?” demanded the programmer.

Master Foo frowned thoughtfully, tapped the programmer twice on the nose, and dropped him in a nearby trashcan.

As the programmer was attempting to extricate himself from the garbage, the dog wandered over and piddled on him.

At that moment, the programmer achieved enlightenment.

Master Foo and the Old Hand

An experienced Unix programmer, hearing of Master Foo's wisdom, came to him for guidance. Approaching the Master, he bowed three times and said:

“Master Foo, I am gravely troubled. In my youth, those who followed the Great Way of Unix used software that was simple and unaffected, like ed and mailx. Today, they use vim and mutt. Tomorrow I fear they will use KMail and Evolution, and Unix will have become like Windows — bloated and covered over with GUIs.”

Master Foo said: “But what software do you use when you want to draw a poster?”

The programmer replied: “I...have never done that. But I am sure that I could use LaTeX or pic to accomplish it without GUIs, in the proper Unix way.”

Master Foo then said: “Which one will reach the other side of the river: The one who dreams of a raft, or the one that hitchhikes to the next bridge?”

Upon hearing this, the programmer was enlightened.

Master Foo and the Shell Tools

A Unix novice came to Master Foo and said: “I am confused. Is it not the Unix way that every program should concentrate on one thing and do it well?”

Master Foo nodded.

The novice continued: “Isn't it also the Unix way that the wheel should not be reinvented?”

Master Foo nodded again.

“Why, then, are there several tools with similar capabilities in text processing: sed, awk and Perl? With which one can I best practice the Unix way?”

Master Foo asked the novice: “If you have a text file, what tool would you use to produce a copy with a few words in it replaced by strings of your choosing?”

The novice frowned and said: “Perl's regexps would be excessive for so simple a task. I do not know awk, and I have been writing sed scripts in the last few weeks. As I have some experience with sed, at the moment I would prefer it. But if the job only needed to be done once rather than repeatedly, a text editor would suffice.”

Master Foo nodded and replied: “When you are hungry, eat; when you are thirsty, drink; when you are tired, sleep.”

Upon hearing this, the novice was enlightened.

Master Foo and the Nervous Novice

There was a novice who learned much at the Master's feet, but felt something to be missing. After meditating on his doubts for some time, he found the courage to approach Master Foo about his problem.

“Master Foo,” he asked “why do Unix users not employ antivirus programs? And defragmentors? And malware cleaners?”

Master Foo smiled, and said “When your house is well constructed, there is no need to add pillars to keep the roof in place.”

The novice replied “Would it not be better to use these things anyway, just to be certain?”

Master Foo reached for a nearby ball of string, and began wrapping it around the novice's feet.

“What are you doing?” the novice asked in surprise.

Master Foo replied simply: “Tying your shoes.”

Upon hearing this, the novice was enlightened.

Master Foo Discourses on Returning to Windows

A student said: “We have learned that Unix is not just an operating system, but also a style of approaching problems.”

Master Foo nodded in agreement.

The student continued: “Then, the Great Way of Unix can be applied on other operating systems?”

Master Foo sat silent for a moment, then said: “In every operating system there is a path to the Great Way, if only we can find it.”

The student continued: “What, then, of Windows? It is preinstalled on most computers, and though its tools are mostly far inferior, they are easy to use for beginners. Surely, Windows users could benefit from the Unix philosophy.”

Master Foo nodded again.

The student said: “How, then, are those enlightened in the Unix Way to return to the Windows world?”