NAME

       ctwill, ctwill-refsort, ctwill-twinx - translate CWEB to TeX with mini-indexes

SYNOPSIS

       ctwill [options] webfile[.w] [{changefile[.ch]|-} [outfile[.tex]]]
       ctwill-refsort < indexfile.ref > indexfile.sref
       ctwill-twinx outfile.tex [outfile.tex ...] > index.tex

DESCRIPTION

       The  ctwill  program converts a CWEB source document 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/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/C++.

USAGE

       The command line should have one, two, or three names on it.  The first is taken as the CWEB  input  file
       (and  .w  is added if there is no extension).  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 CWEB 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 .tex.
       If  you  just want to change the output file name, but don’t have a change file to apply, you can use `-'
       as the second argument.

       ctwill is exactly like cweave except that it produces much better documentation, for which you must  work
       much  harder.   You  should  run  ctwill  twice,  once  to prime the pump and once to get decent answers.
       Moreover, you must run the output twice through TeX.

       After tex foo you will have output that looks like final pages except that the  entries  of  mini-indexes
       won’t be alphabetized.  The first run produces a weird file called foo.ref.  Say ctwill-refsort < foo.ref
       > foo.sref and then another tex foo will produce alphabetized output.

       The ctwill-twinx program compiles a master index for a set of related programs that have  been  processed
       by  ctwill  (not by cweave, mind you!).  The individual programs should define their names with a line of
       the form \def\title{NAME}.  For your convenience, ctwill-twinx grabs the first “word” in \title and turns
       it into uppercase form.  You should adapt file twinx-startup.tex for the first page of the master index.

       The  mini-indexes  list identifiers that are used but not defined on each two-page spread.  At the end of
       each section, ctwill gives TeX a list of identifiers used in that section  and  information  about  where
       they are defined.

       The current meaning of every identifier is initially \uninitialized.  Then ctwill reads the .aux file for
       your job, if any.

       Before reading the .aux file, ctwill actually looks for a file called system.bux, which will be  read  if
       present.   And  after  foo.aux,  a  third  possibility  is  foo.bux.   The  general  convention is to put
       definitions of system procedures such as  printf  into  system.bux,  and  to  put  definitions  found  in
       specifically  foo-ish  header files into foo.bux.  Like the .aux files, .bux files should contain only @$
       specifications.

       The meaning specified by @$...@> generally has four components: an  identifier  (followed  by  space),  a
       program name (enclosed in braces), a section number (followed by space), and a TeX part.

       A  special  proofmode is provided so that you can check ctwill’s conclusions about cross-references.  Run
       ctwill with the flag +P, and TeX will produce a specially formatted document  (without  mini-indexes)  in
       which you can check that your specifications are correct.

       More  details  how  to use ctwill can be found in the first sections of its source code, respectively the
       change file cweav-twill.ch applicable to the cweave.w source.  A complete  example  with  all  bells  and
       whistles is described in Mini-Indexes for Literate Programs, pages 225–245 of Knuth’s Digital Typography.

DIFFERENCES TO ORIGINAL CTWILL

       The  present  incarnation  of  ctwill  and  its  utilities tries hard to be a drop-in replacement for the
       original package.  There are, however, a few differences worth noting:

       • This version is based on the most recent version of CWEB (4.4).

       • In TeX Live the utility programs are prefixed with ctwill- and the macro files with  ct  for  technical
         reasons.

       • Options  --help,  --quiet,  --verbose,  --version, and flags -c, -i, -o, and +lX are new in CWEBbin and
         TeX Live.

       • Option +lX is accompanied by example wrapper files for ctwimac.tex and ctproofmac.tex  with  translated
         captions for German (+ld).

       • Option  +lX  is also accompanied by an extended pdfctwimac.tex for production of PDF output with active
         hyperlinks (+lpdf).

       • ctwill in TeX Live operates silently by default; use the --verbose option to get the original behavior.

       • File lookup with the environment variable CWEBINPUTS is extended to  permit  several,  colon-separated,
         paths; see ENVIRONMENT below.

       • If properly configured, the main program ctwill is localized with the “GNU gettext utilities”.

OPTIONS

       Options  on  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  --verbose  -h will only show the banner line (+b) and the progress report (+p), but leave
       out the happy message (-h).

       • +b: print banner line on terminal

       • +h: print success message on completion

       • +p: print progress report messages

       • +q/-q: shortcut for -bhp; also --quiet (default)

       • +v/-v: shortcut for +bhp; also --verbose

       • -c: ignore temporary output irrespective of changes

       • -e: do not enclose C/C++ material in \PB{...}

       • -f: do not force a newline after every C/C++ statement in output

       • -i: suppress indentation of parameter declarations

       • -o: suppress separation of declarations and statements

       • -x: omit indices, section names, table of contents

       • +P: \input ctproofmac.tex instead of ctwimac.tex

       • +lX/-lX: use macros for language X as of X{ctwimac|ctproofmac}.tex

       • +s: print usage statistics

       • +t: treat typename in a template like typedef

       • --help: display help message and exit

       • --version: output version information and exit

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.  To avoid conflicts with other
       programs that also use the CWEBINPUTS environment, you can be more specific and use  CWEBINPUTS_cweb  for
       special requirements in CWEB.

       If  prepared for NLS support, ctwill like ctangle and cweave uses the environment variable TEXMFLOCALEDIR
       to configure the parent directory where the “GNU gettext utilities” search for translation catalogs.

       These variables are preconfigured in TeX Live’s texmf.cnf.

FILES

       The location of the files mentioned below varies from system to system.  Use  the  kpsewhich  utility  to
       find their locations.

       • ctwimac.tex: The default TeX macros \input in the first line of the output file.

       • ctproofmac.tex:  If  ctwill  is invoked with the +P option, it will change the first line of the output
         file to \input ctproofmac.tex.

       In both cases you can request some prefix X with the +lX option, e.g., +ld will \input  dctwimac.tex  and
       +Pld  will  \input  dctproofmac.tex.   A  special application is the use of option +lpdf that will \input
       pdfctwimac.tex for production of PDF output with active hyperlinks.

       • webfile.bux: Reference definitions to resolve from other modules.

       • system.bux: Reference definitions to resolve from C/C++ standard library header files like <stdio.h>.

       Other auxiliary files with references are created automatically by ctwill and the actual index files  are
       created by TeX.

       • cwebman.tex: The CWEB user manual, available in PDF from CTAN (https://ctan.org/pkg/cweb).

SEE ALSO

       • The  CWEB  System  of Structured Documentation: by Donald E. Knuth and Silvio Levy (hardcopy version of
         cwebman.tex and the source code listings of common.w, ctangle.w, and cweave.w).

       • Digital Typography: by D. E. Knuth.

       • Literate Programming: by D. E. Knuth.

       • Weaving a Program: by Wayne Sewell.

       cweb(1), tex(1), cc(1)

AUTHORS

       Don Knuth wrote ctwill based on cweave by Silvio Levy and Knuth.
       Contemporary development on https://github.com/ascherer/cwebbin.