TECO
<editor, text> /tee'koh/ (Originally an acronym for "[paper] Tape Editor and COrrector"; later, "Text Editor and COrrector"]) A
text editor developed at
MIT and modified by just about everybody.
With all the dialects included, TECO may have been the most prolific editor in use before
Emacs, to which it was directly ancestral.
The first
Emacs editor was written in TECO.
It was noted for its powerful programming-language-like features and its unspeakably
hairy syntax (see
write-only language).
TECO programs are said to resemble
line noise. Every string of characters is a valid TECO program (though probably not a useful one); one common game used to be predict what the TECO commands corresponding to human names did.
As an example of TECO's obscurity, here is a TECO program that takes a list of names such as:
Loser, J. Random Quux, The Great Dick, Moby
sorts them alphabetically according to surname, and then puts the surname last, removing the comma, to produce the following:
Moby Dick J. Random Loser The Great Quux
The program is
[1 J^P$L$$ J <.-Z; .,(S,$ -D .)FX1 @F^B $K :L I $ G1 L>$$
(where ^B means "Control-B" (ASCII 0000010) and $ is actually an
alt or escape (ASCII 0011011) character).
In fact, this very program was used to produce the second, sorted list from the first list.
The first hack at it had a
bug: GLS (the author) had accidentally omitted the "@" in front of "F^B", which as anyone can see is clearly the
Wrong Thing.
It worked fine the second time.
There is no space to describe all the features of TECO, but "^P" means "sort" and "J<.-Z; ... L>" is an idiomatic series of commands for "do once for every line".
By 1991,
Emacs had replaced TECO in hacker's affections but descendants of an early (and somewhat lobotomised) version adopted by
DEC can still be found lurking on
VMS and a couple of crufty
PDP-11 operating systems, and ports of the more advanced MIT versions remain the focus of some antiquarian interest.
See also
retrocomputing.
(ftp://usc.edu/) for
VAX/
VMS,
Unix,
MS-DOS,
Macintosh,
Amiga.
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