TECO

TECO /tee'koh/ n.,v.,obs.  1. [originally an acronym for
   `[paper] Tape Editor and COrrector'; later, `Text Editor and
   COrrector'] n. 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.  Noted for its powerful
   programming-language-like features and its unspeakably hairy
   syntax.  It is literally the case that every string of characters
   is a valid TECO program (though probably not a useful one); one
   common game used to be mentally working out what the TECO commands
   corresponding to human names did.  2. vt. Originally, to edit using
   the TECO editor in one of its infinite variations (see below).
   3. vt.,obs.  To edit even when TECO is *not* the editor being
   used!  This usage is rare and now primarily historical.

   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 it may be of interest that `^P' means
   `sort' and `J<.-Z; ... L>' is an idiomatic series of commands
   for `do once for every line'.

   In mid-1991, TECO is pretty much one with the dust of history,
   having been replaced in the affections of hackerdom by {EMACS}.
   Descendants of an early (and somewhat lobotomized) version adopted
   by DEC can still be found lurking on VMS and a couple of crufty
   PDP-11 operating systems, however, and ports of the more advanced
   MIT versions remain the focus of some antiquarian interest.  See
   also {retrocomputing}, {write-only language}.