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.