資料來源 : Free On-Line Dictionary of Computing
metasyntactic variable
Strictly, a {variable} used in {metasyntax}, but
often used for any name used in examples and understood to
stand for whatever thing is under discussion, or any random
member of a class of things under discussion. The word {foo}
is the {canonical} example. To avoid confusion, hackers never
(well, hardly ever) use "foo" or other words like it as
permanent names for anything.
In filenames, a common convention is that any filename
beginning with a metasyntactic-variable name is a {scratch}
file that may be deleted at any time.
To some extent, the list of one's preferred metasyntactic
variables is a cultural signature. They occur both in series
(used for related groups of variables or objects) and as
singletons. Here are a few common signatures:
{foo}, {bar}, {baz}, {quux}, quuux, quuuux...: MIT/Stanford
usage, now found everywhere. At MIT (but not at Stanford),
{baz} dropped out of use for a while in the 1970s and '80s. A
common recent mutation of this sequence inserts {qux} before
{quux}.
bazola, ztesch: Stanford (from mid-'70s on).
{foo}, {bar}, thud, grunt: This series was popular at CMU.
Other CMU-associated variables include ack, barf, foo, and
{gorp}.
{foo}, {bar}, fum: This series is reported to be common at
{Xerox PARC}.
{fred}, {barney}: See the entry for {fred}. These tend to be
Britishisms.
{toto}, titi, tata, tutu: Standard series of metasyntactic
variables among francophones.
{corge}, {grault}, {flarp}: Popular at Rutgers University and
among {GOSMACS} hackers.
zxc, spqr, {wombat}: Cambridge University (England).
shme: Berkeley, GeoWorks, Ingres. Pronounced /shme/ with a
short /e/.
{foo}, {bar}, zot: {Helsinki University of Technology},
Finland.
blarg, wibble: New Zealand
Of all these, only "foo" and "bar" are universal (and {baz}
nearly so). The compounds {foobar} and "foobaz" also enjoy
very wide currency.
Some jargon terms are also used as metasyntactic names; {barf}
and {mumble}, for example.
See also {Commonwealth Hackish} for discussion of numerous
metasyntactic variables found in Great Britain and the
Commonwealth.
[{Jargon File}]
(1995-11-13)