Provided by: texlive-binaries_2015.20160222.37495-1ubuntu0.1_amd64 
NAME
ctangle, cweave - translate CWEB to C and/or TeX
SYNOPSIS
ctangle [-bhp] [+s] webfile[.w] [{changefile[.ch]|-} [outfile[.c]]]
cweave [-befhpx] [+s] webfile[.w] [{changefile[.ch]|-} [outfile[.tex]]]
DESCRIPTION
The ctangle program converts a CWEB source document into a C program that may be compiled in the usual
way. The output 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 compilable 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 recommended, 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 processed from left to right, so a
sequence like -f +f corresponds 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 compiled 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.
ENVIRONMENT
The environment variable CWEBINPUTS is used to search for the input files, or the system default if
CWEBINPUTS is not set. See tex(1) for the details of the searching.
FILES
The location of the files mentioned below varies from system to system. Use the kpsewhich utility to
find their locations.
cwebmac.tex
TeX macros used by cweave output.
cwebman.tex
The user manual.
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 version 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
conventions 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.