metasyntactic variable
n. A 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 (thanks largely to early
versions of this lexicon!). 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 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.