ching, fortune - the book of changes and other cookies
/usr/games/ching [ hexagram ]
The I Ching or Book of Changes is an ancient Chinese oracle that has been in use for cen-
turies as a source of wisdom and advice.
The text of the oracle (as it is sometimes known) consists of sixty-four hexagrams, each
symbolized by a particular arrangement of six straight (---) and broken (- -) lines.
These lines have values ranging from six through nine, with the even values indicating the
Each hexagram consists of two major sections. The Judgement relates specifically to the
matter at hand (E.g., "It furthers one to have somewhere to go.") while the Image
describes the general attributes of the hexagram and how they apply to one's own life
("Thus the superior man makes himself strong and untiring.").
When any of the lines have the values six or nine, they are moving lines; for each there
is an appended judgement which becomes significant. Furthermore, the moving lines are
inherently unstable and change into their opposites; a second hexagram (and thus an addi-
tional judgement) is formed.
Normally, one consults the oracle by fixing the desired question firmly in mind and then
casting a set of changes (lines) using yarrow-stalks or tossed coins. The resulting hexa-
gram will be the answer to the question.
Using an algorithm suggested by S. C. Johnson, the Unix oracle simply reads a question
from the standard input (up to an EOF) and hashes the individual characters in combination
with the time of day, process id and any other magic numbers which happen to be lying
around the system. The resulting value is used as the seed of a random number generator
which drives a simulated coin-toss divination. The answer is then piped through nroff for
formatting and will appear on the standard output.
For those who wish to remain steadfast in the old traditions, the oracle will also accept
the results of a personal divination using, for example, coins. To do this, cast the
change and then type the resulting line values as an argument.
The impatient modern may prefer to settle for Chinese cookies; try fortune.
It furthers one to see the great man.
The great prince issues commands,
Founds states, vests families with fiefs.
Inferior people should not be employed.
Waiting in the mud
Brings about the arrival of the enemy.
If one is not extremely careful,
Somebody may come up from behind and strike him.