.TH WEB 1 "7 Jan 92"
.SH NAME
tangle, weave \- translate WEB to Pascal and/or TeX
.SH SYNOPSIS
.B tangle
webfile[.web] [changefile[.ch]]
.br
.B weave
[-x] webfile[.web] [changefile[.ch]]
.SH DESCRIPTION
The
.I 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.,
.BR 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.
.PP
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.
.PP
The command line should have either one or two names on it.
The first is taken as the WEB file (and 
.I .web
is added if there is no
extension).
If there is another name, it is a change file (and 
.I .ch
is added if there is
no extension).  The change file overrides parts of the WEB file,
as described in the WEB system documentation.
.PP
The output files are a Pascal file and a string pool file,
whose names are formed by adding
.I .p
and 
.I .pool
respectively to the root of the WEB file name.
.PP
The 
.I weave
program is used to create a TeX file for viewing the WEB program.
It takes appropriate care of typographic details like page
layout and the use of indentation, italics, boldface, etc., and it supplies
extensive cross-index information that it gathers automatically.
The command line arguments are the same as for
.I tangle
except for the option:
.B \-x
says to omit the index, module name list, and table of contents pages.
(A 
.I CONTENTS.tex
file will still be written when the TeX file is processed,
however, unless some macros in
.I webmac.tex
are redefined.)
.PP
The output TeX file name is formed by adding
.I .tex
to the root of the WEB file name.
.PP
There are several macros
that probably should be redefined by
the programmer at the beginning of the WEB file.
It is a good idea to set \\title
to the name of the program.
And, to cause output of only changed modules, one can say
\\let\\maybe=\\iffalse (usually as the first change in the
change file).
.SH FILES
/usr/local/lib/tex/macros/webmac.tex   TeX macros used by weave output.
.SH "SEE ALSO"
.I The WEB System of Structured Documentation
and
.IR Literate Programming ,
by D.E. Knuth.
.br
.IR Weaving a Program ,
by Wayne Sewell
.br
tex(1), pc(1)
.br
pxp(1) (for formatting tangle output when debugging)
.br
.I TeX: The Program
and
.I METAFONT: The
.IR Program , volumes B and D in the
.I Computers and Typesetting
series, published by Addison-Wesley, are by far the largest extant
examples of WEB programs.
.SH AUTHORS
WEB was designed by Donald E. Knuth, based on an earlier system
called DOC (implemented by Ignacio Zabala).
The
.I tangle
and
.I 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.