CHING(6) BSD Games Manual CHING(6)
ching -- the book of changes and other cookies
The I Ching or Book of Changes is an ancient Chinese oracle that has been in use for centuries 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 broken
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 additional judgement)
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 hexagram 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(1) 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(6).
The great prince issues commands,
Founds states, vests families with fiefs.
Inferior people should not be employed.
It furthers one to see the great man.
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.
May 31, 1993 BSD