NAME

       tangle - translate WEB to Pascal

SYNOPSIS

       tangle [options] webfile[.web] [{changefile[.ch]|-} [outfile[.p]]]

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 one, two or three names on it.  The first is taken as the Web file (and .web
       is added if there is no extension).  If there is second 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.

       If there is a third name, it is the Pascal output file (and .p is added if there  is  no  extension).  In
       this  case  you  can specify an empty change file with '-' as the second argument.  Otherwise the name of
       the Pascal file is formed by adding .p to the root of the Web file name.

       An optional second output file is a string pool file, whose name is formed by adding .pool to the root of
       the Pascal 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.

Web2C 2023                                        02 March 2022                                        TANGLE(1)