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 documentation 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 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.

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  settings  of  the
              --lowercase,  --mixedcase,  --uppercase,  and  --underline  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 underlines 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: 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.