TANGLE(1)                   General Commands Manual                  TANGLE(1)



NAME
       tangle - translate WEB to Pascal

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

DESCRIPTION
       This  manual page is not meant to be exhaustive.  The complete documen-
       tation for this version of TeX can be found in the info file or  manual
       Web2C: A TeX implementation.

       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 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 pro-
       gram 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 sim-
       ple, 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.

OPTIONS
       This  version  of  tangle understands the following options.  Note that
       some of these options may render the output unsuitable  for  processing
       by a Pascal compiler.

       --help Print help message and exit.

       --length number
              Compare  only  the  first  number characters of identifiers when
              checking for collisions.  The default is 32, the original tangle
              used 7.

       --loose
              When checking for collisions between identifiers, honor the set-
              tings of the --lowercase, --mixedcase, --uppercase, and --under-
              line options. This is the default.

       --lowercase
              Convert all identifiers to lowercase.

       --mixedcase
              Retain the case of identifiers.  This is the default.

       --strict
              When  checking  for collisions between identifiers, strip under-
              lines and convert all identifiers to uppercase first.

       --underline
              Retain underlines (also known as underscores) in identifiers.

       --uppercase
              Convert all identifiers to uppercase.  This is the behaviour  of
              the original tangle.

       --version
              Print version information and exit.

ENVIRONMENT
       The  environment  variable  WEBINPUTS  is  used to search for the input
       files, or the system default if WEBINPUTS is not set.  See  tex(1)  for
       the details of the searching.

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 for nroff: 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 Type-
       setting), 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 sub-
       ject 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.



Web2C 2015/dev                   1 March 2011                        TANGLE(1)
