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 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  com-
       piler (e.g., pc(1)).  The output file is packed into lines of 72 characters or less, with the only concession to readability being the ter-
       mination 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  pro-
       gram 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 exten-
       sion).  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 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 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 2012							   1 March 2011 							 TANGLE(1)