CWEB(1L)CWEB(1L)NAME
ctangle, cweave - translate CWEB to C and/or TeX
SYNOPSIS
ctangle [ -bhp ] [ +s ] webfile[.w] [changefile[.ch]]
[outputfile[.c]]
cweave [ -befhpx ] [ +s ] webfile[.w] [changefile[.ch]]
[outputfile[.tex]]
DESCRIPTION
The ctangle program converts a CWEB source document into a
C program that may be compiled in the usual way. The out-
put file includes #line specifications so that debugging
can be done in terms of the CWEB source file.
The cweave program converts the same CWEB file into a TeX
file that may be formatted and printed in the usual way.
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.
CWEB allows you to prepare a single document containing
all the information that is needed both to produce a com-
pilable C program and to produce a well-formatted document
describing the program in as much detail as the writer may
desire. The user of CWEB ought to be familiar with TeX as
well as C.
The command line should have one, two, or three names on
it. The first is taken as the CWEB file (and .w is added
if there is no extension). If that file cannot be opened,
the extension .web is tried instead. (But .w is recom-
mended, since .web usually implies Pascal.) If there is a
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 documentation. If
there is a third name, it overrides the default name of
the output file, which is ordinarily the same as the name
of the input file (but on the current directory) with the
extension .c or .tex.
Options in the command line may be either turned off
with - (if they are on by default) or turned on with + (if
they are off by default). In fact, the options are pro-
cessed from left to right, so a sequence like -f +f corre-
sponds to +f (which is the default).
The -b option suppresses the banner line that normally
appears on your terminal when ctangle or cweave begins.
The -h option suppresses the happy message that normally
appears if the processing was successful. The -p option
suppresses progress reports (starred module numbers) as
the processing takes place. If you say -bhp, you get
nothing but error messages.
The +s option prints statistics about memory usage at the
end of a run (assuming that the programs have been com-
piled with the -DSTAT switch).
There are three other options applicable to cweave only:
-f means do not force a newline after every statement in
the formatted output. -e inhibits the enclosure of
C material formatted by cweave in brackets \PB{...}. Such
brackets are normally inserted so that special hooks can
be used by cweb-latex and similar programs. -x means omit
the index and table of contents.
FILES
/usr/local/lib/tex/inputs/cwebmac.tex
TeX macros used by cweave output.
/usr/local/src/cweb/cwebman.tex
The user manual.
/usr/local/src/cweb/examples/wc.w
An introductory example.
/usr/local/src/cweb/examples/wmerge.w
Patch program based on CWEB-style change files.
/usr/local/lib/cweb
Directory for cweb "include" files.
SEE ALSO
Literate Programming
by D. E. Knuth
Weaving a Program
by Wayne Sewell
The CWEB System of Structured Documentation
by Donald E. Knuth and Silvio Levy (hardcopy ver-
sion of cwebman.tex and the source code listings)
tex(1), cc(1)AUTHORS
Don Knuth wrote WEB for TeX and Pascal. Silvio Levy
designed and developed CWEB by adapting the WEB conven-
tions to C and by recoding everything in CWEB. Knuth
began using CWEB and made further refinements. Many other
helpers are acknowledged in the CWEB manual.
2002-Apr-13 CWEB(1L)
