NAME
          tangle - translate WEB to Pascal

     SYNOPSIS
          tangle webfile[.web] [ changefile[.ch] ]

     DESCRIPTION
          The tangle program converts a Web source document into a
          Pascal program that may be compiled in the usual way with
          the on-line Pascal compiler (e.g., pc(1)).  The output file
          is all in lower case and packed into lines of 72 characters
          or less, with the only concession to readability being the
          termination of lines at semicolons when this can be done
          conveniently.

          The Web language allows you to prepare a single document
          containing all the information that is needed both to
          produce a compilable Pascal program and to produce a well-
          formatted document describing the program in as much detail
          as the writer may desire.  The user of Web must be familiar
          with both TeX and Pascal.  Web also provides a relatively
          simple, although adequate, macro facility that permits a
          Pascal program to be written in small easily-understood
          modules.

          The command line should have either one or two names on it.
          The first is taken as the Web file (and .web is added if
          there is no extension).  If there is another name, it is a
          change file (and .ch is added if there is no extension).
          The change file overrides parts of the Web file, as
          described in the Web system documentation.

          The output files are a Pascal file and a string pool file,
          whose names are formed by adding .p and .pool respectively
          to the root of the Web file name.

     SEE ALSO
          pc(1), pxp(1) (for formatting tangle output when debugging),
          tex(1).

          Donald E. Knuth, The Web System of Structured Documentation.

          Donald E. Knuth, Literate Programming, Computer Journal 27,
          97-111, 1984.

          Wayne Sewell, Weaving a Program, Van Nostrand Reinhold,
          1989, ISBN 0-442-31946-0.

          Donald E. Knuth, TeX: The Program (Volume B of Computers and
          Typesetting), Addison-Wesley, 1986, ISBN 0-201-13437-3.

          Donald E. Knuth, Metafont: The Program (Volume D of
          Computers and Typesetting), Addison-Wesley, 1986, ISBN 0-
          201-13438-1.

          These last two are by far the largest extant examples of Web
          programs.

          There is an active Internet electronic mail discussion list
          on the subject of literate programming; send a subscription
          request to litprog-request@shsu.edu to join.

     AUTHORS
          Web was designed by Donald E. Knuth, based on an earlier
          system called DOC (implemented by Ignacio Zabala).  The
          tangle and weave programs are themselves written in Web. The
          system was originally ported to Unix at Stanford by Howard
          Trickey, and at Cornell by Pavel Curtis.