.TH TANGLE 1 "12 February 1993" "Web2C @VERSION@"
.\"=====================================================================
.if n .ds MF Metafont
.if t .ds MF M\s-2ETAFONT\s0
.if t .ds TX \fRT\\h'-0.1667m'\\v'0.20v'E\\v'-0.20v'\\h'-0.125m'X\fP
.if n .ds TX TeX
.ie t .ds OX \fIT\v'+0.25m'E\v'-0.25m'X\fP\" for troff
.el .ds OX TeX\" for nroff
.\" the same but obliqued
.\" BX definition must follow TX so BX can use TX
.if t .ds BX \fRB\s-2IB\s0\fP\*(TX
.if n .ds BX BibTeX
.\" LX definition must follow TX so LX can use TX
.if t .ds LX \fRL\\h'-0.36m'\\v'-0.15v'\s-2A\s0\\h'-0.15m'\\v'0.15v'\fP\*(TX
.if n .ds LX LaTeX
.if n .ds WB Web
.if t .ds WB W\s-2EB\s0
.\"=====================================================================
.SH NAME
tangle \- translate WEB to Pascal
.SH SYNOPSIS
.B tangle
.I webfile[.web]
[
.I changefile[.ch]
]
.\"=====================================================================
.SH DESCRIPTION
This manual page is not meant to be exhaustive.  The complete
documentation for this version of \*(TX can be found in the info file
or manual
.IR "Web2C: A TeX implementation" .
.PP
The
.B tangle
program converts a \*(WB
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 \*(WB 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 \*(WB must be
familiar with both \*(TX and Pascal.  \*(WB 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 \*(WB 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 \*(WB file,
as described in the \*(WB 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 \*(WB file name.
.\"=====================================================================
.SH "SEE ALSO"
.BR pc (1),
.BR pxp (1)
(for formatting
.B tangle
output when debugging),
.BR tex (1).
.PP
Donald E. Knuth,
.IR "The \*(WB System of Structured Documentation" .
.PP
Donald E. Knuth,
.IR "Literate Programming" ,
Computer Journal
.BR 27 ,
97\-111, 1984.
.PP
Wayne Sewell,
.IR "Weaving a Program" ,
Van Nostrand Reinhold, 1989, ISBN 0-442-31946-0.
.PP
Donald E. Knuth,
.I "\*(OX: The Program"
(Volume B of
.IR "Computers and Typesetting" ),
Addison-Wesley, 1986, ISBN 0-201-13437-3.
.PP
Donald E. Knuth,
.I "\*(MF: The Program"
(Volume D of
.IR "Computers and Typesetting" ),
Addison-Wesley, 1986, ISBN 0-201-13438-1.
.PP
These last two are by far the largest extant examples of \*(WB
programs.
.PP
There is an active Internet electronic mail discussion list on the
subject of literate programming; send a subscription request to
.I litprog-request@shsu.edu
to join.
.\"=====================================================================
.SH AUTHORS
\*(WB was designed by Donald E. Knuth, based on an earlier system
called DOC (implemented by Ignacio Zabala).
The
.B tangle
and
.B weave
programs are themselves written in \*(WB. The system
was originally ported to Unix at Stanford by Howard Trickey, and at
Cornell by Pavel Curtis.