%\iffalse
%<*dtx>
\ProvidesFile
%========================================================================
                        {MAKEBST.DTX}
%========================================================================
%</dtx>
%  This is a (La)TeX program that generates docstrip batch jobs
%    that may be used to produce customized bibliographic style files.
%     Docstrip options available:
%        program - to generate the program file, makebst.tex
%        optlist - (with program) to list unused options in .dbj file
%        driver  - to produce a LaTeX2e driver file to print the documentation
%  Installation:
%    LaTeX this file: ==> docstrip installation file makebst.ins
%                         AND the (LaTeX2e) documentation
%    (La)TeX makebst.ins: ==> `program' file makebst.tex
%    (makebst.ins may be edited as needed)
%-------------------------------------------------------------------
%<program>\def\ProvidesFile#1 [#2 #3 #4]{\def\filename{#1}%
%<program>  \def\fileversion{#3}\def\filedate{#2}}
%<*program>
%\fi
 \ProvidesFile{makebst}
    [1995/03/15 3.0 (PWD)]
%\iffalse
 %-------------------------------------------------------------------
 % NOTICE:
 % This file may be used for non-profit purposes.
 % It may not be distributed in exchange for money, 
 %   other than distribution costs.
 %   
 % The author provides it `as is' and does not guarantee it in any way.
 % 
%% Copyright (C) 1994, 1995 Patrick W. Daly
 % Max-Planck-Institut f\"ur Aeronomie
 % Postfach 20
 % D-37189 Katlenburg-Lindau
 % Germany
 % 
 % E-mail:
 % SPAN--     nsp::linmpi::daly 
 % Internet-- daly@linmpi.dnet.gwdg.de   
 %-----------------------------------------------------------
%  Here follows abbreviated usage description for the stripped version
 % This file is to be run under TeX (or even LaTeX) 
 % It interactively asks questions about the bibliographic style file
 % that you want to produce. When it is finished, it writes a docstrip
 % driver file that produces that .bst file from the generic .mbs that
 % you specified; optionally, it will call the docstrip run immediately.
 % For details, read the documentation in the source file makebst.dtx.
 %--------------------------------------------------------------------
%</program>
%\fi
% \changes{1.0}{1993 Aug 17}{Initial version}
% \changes{1.1}{1994 May 25}{Change extensions to avoid \LaTeXe\ conflicts}
% \changes{2.0}{1994 Jul 01}{Update documentation to \LaTeXe}
% \changes{2.1}{1994 Dec 29}{Add the \texttt{optlist} option}
% \changes{2.1}{1995 Jan 2}{Read \texttt{.opt} file only exceptionally}
% \changes{3.0}{1995 Mar 15}{Allow \texttt{.mbs} files more freedom, to 
%        include other files, for example}
%
% \CheckSum{532}
% \CharacterTable
%  {Upper-case    \A\B\C\D\E\F\G\H\I\J\K\L\M\N\O\P\Q\R\S\T\U\V\W\X\Y\Z
%   Lower-case    \a\b\c\d\e\f\g\h\i\j\k\l\m\n\o\p\q\r\s\t\u\v\w\x\y\z
%   Digits        \0\1\2\3\4\5\6\7\8\9
%   Exclamation   \!     Double quote  \"     Hash (number) \#
%   Dollar        \$     Percent       \%     Ampersand     \&
%   Acute accent  \'     Left paren    \(     Right paren   \)
%   Asterisk      \*     Plus          \+     Comma         \,
%   Minus         \-     Point         \.     Solidus       \/
%   Colon         \:     Semicolon     \;     Less than     \<
%   Equals        \=     Greater than  \>     Question mark \?
%   Commercial at \@     Left bracket  \[     Backslash     \\
%   Right bracket \]     Circumflex    \^     Underscore    \_
%   Grave accent  \`     Left brace    \{     Vertical bar  \|
%   Right brace   \}     Tilde         \~}
%
%\iffalse
%<*install>
%^^A =============================================
%^^A    Here is the docstrip installation file
%^^A    It is written on first LaTeX run
%^^A =============================================
\begin{filecontents}{makebst.ins}
% Simply TeX or LaTeX this file to extract various files from 
%  the source file `makebst.dtx'

\def\batchfile{makebst.ins}
\input docstrip

\preamble

This is the `program' part of the source file.
It may be run either with TeX or LaTeX.

\endpreamble
\postamble
<<<<< End of decommented file <<<<<<

End of file \noexpand\outFileName.
\endpostamble
\keepsilent

% Two variants on makebst.tex; comment out one of the \generateFile lines

% In this version, the .dbj file contains only the list of selected options
% \generateFile{makebst.tex}{f}{\from{makebst.dtx}{program}}

% In this version, the .dbj file contains a list of all offered options, 
%    with the non-selected ones commented out.
\generateFile{makebst.tex}{f}{\from{makebst.dtx}{program,optlist}}

\preamble

This is the driver file to produce the LaTeX documentation from the 
source file \inFileName.
Make changes to it as needed.
\endpreamble
\postamble

End of documentation driver file \noexpand\outFileName.
\endpostamble

\generateFile{makebst.drv}{f}{\from{makebst.dtx}{driver}}

\obeyspaces
\Msg{******************************************}%
\Msg{* For documentation, process makebst.dtx *}%
\Msg{*    or the driver file      makebst.drv *}%
\Msg{* (LaTeX2e only!)                        *}%
\Msg{******************************************}
\end{filecontents}
%</install>
%<*driver>
\NeedsTeXFormat{LaTeX2e}
\documentclass{ltxdoc}
%<driver>%\EnableCrossrefs %Comment out when .ind file ready
  \DisableCrossrefs %May stay; zapped by \EnableCrossrefs
%<driver>%\RecordChanges %Comment out when .gls file ready
%<driver>%\CodelineIndex %Comment out when .ind file ready
  \CodelineNumbered %May stay
%<driver>%\OnlyDescription
\begin{document}
   \DocInput{makebst.dtx}
\end{document}
%</driver>
%\fi
%
% \DoNotIndex{\begin,\CodelineIndex,\CodelineNumbered,\def,\DisableCrossrefs}
% \DoNotIndex{\DocInput,\documentclass,\EnableCrossrefs,\end,\GetFileInfo}
% \DoNotIndex{\NeedsTeXFormat,\OnlyDescription,\RecordChanges,\usepackage}
% \DoNotIndex{\ProvidesClass,\ProvidesPackage,\ProvidesFile,\RequirePackage}
% \DoNotIndex{\LoadClass,\PassOptionsToClass,\PassOptionsToPackage}
% \DoNotIndex{\DeclareOption,\CurrentOption,\ProcessOptions,\ExecuteOptions}
% \DoNotIndex{\AtEndOfClass,\AtEndOfPackage,\AtBeginDocument,\AtEndDocument}
% \DoNotIndex{\InputIfFileExists,\IfFileExists,\ClassError,\PackageError}
% \DoNotIndex{\ClassWarning,\PackageWarning,\ClassWarningNoLine}
% \DoNotIndex{\PackageWarningNoLine,\ClassInfo,\PackageInfo,\MessageBreak}
% \DoNotIndex{\space,\protect,\DeclareRobustCommand,\CheckCommand}
% \DoNotIndex{\newcommand,\renewcommand,\providecommand,\newenvironment}
% \DoNotIndex{\renewenvironment,\newif,\newlength,\newcounter,\setlength}
% \DoNotIndex{\setcounter,\if,\ifx,\ifcase,\ifnum,\ifdim,\else,\fi}
% \DoNotIndex{\texttt,\textbf,\textrm,\textsl,\textsc}
% \DoNotIndex{\textup,\textit,\textmd,\textsf,\emph}
% \DoNotIndex{\ttfamily,\rmfamily,\sffamily,\mdseries,\bfseries,\upshape}
% \DoNotIndex{\slshape,\scshape,\itshape,\em,\LaTeX,\LaTeXe}
% \DoNotIndex{\filename,\fileversion,\filedate,\let,\empty}
% \DoNotIndex{\%,\(,\),\{,\},\@,\@@end,\^,\batchfile,\begingroup,\catcode}
% \DoNotIndex{\closein,\closeout,\csname,\day,\divide,\edef,\endcsname}
% \DoNotIndex{\endgroup,\endinput,\endpostamble,\endpreamble,\expandafter}
% \DoNotIndex{\from,\gdef,\generateFile,\global,\hours,\ifeof,\immediate}
% \DoNotIndex{\input,\keepsilent,\loop,\month,\multiply,\newcount}
% \DoNotIndex{\newlinechar,\newread,\newwrite,\number,\openin,\openout}
% \DoNotIndex{\or,\par,\postamble,\preamble,\read,\relax,\repeat,\string}
% \DoNotIndex{\temp,\time,\undefined,\write,\year}
% \DoNotIndex{\advance,\today,\minutes}
%
% \setcounter{IndexColumns}{2}
% \setlength{\IndexMin}{10cm}
% \setcounter{StandardModuleDepth}{1}
%
% \GetFileInfo{makebst}
% \newcommand\theprog{\texttt{\filename}}
%
% \title{\bfseries Customizing Bibliographic Style Files}
%    
% \author{Patrick W. Daly}
%         
% \date{This paper describes program \theprog\\
%       version \fileversion{} from \filedate\\[1ex]
%  }
% 
% \maketitle
%
%^^A In order to keep all marginal notes on the one (left) side:
%^^A (otherwise they switch sides disastrously with twoside option)
% \makeatletter \@mparswitchfalse \makeatother 
%
% \pagestyle{myheadings}
% \markboth{P. W. DALY}{CUSTOMIZING BIBLIOGRAPHIES}
%         
% \newcommand{\btx}{\textsc{Bib}\TeX}
% \newcommand{\dtx}{\textsf{docstrip}}
%
% \parskip=1ex \parindent=0pt
%
% \section{Introduction}
% This \TeX{} program is meant to be used together with generic
% bibliographic style files to produce customized \texttt{.bst} files for
% running with \btx. The generic, or master file, can be processed by
% \dtx{} with selected options to achieve the desired bibliographic
% style. To this end, a \dtx{} batch job should be made up.
% However, because of the large number of options available, an
% interactive, dialogue system would be more convenient.
% 
% This program, \theprog, accomplishes this goal.
% It defines macros to establish such a \dtx{} batch job file, and
% to organize a menu of options. The menu information is contained,
% however, in the master file itself, since the two are intimately related.
% Thus different master files with totally different option structures may
% be accommodated.
% 
% The batch job could in fact be made up with an editor without calling 
% \theprog, but this program does simplify the task.
% 
% Incidentally, the \dtx{} run can only be carried out by means of
% a batch job. Running \dtx{} interactively inserts default pre- and 
% postambles in the text, the latter including an |\endinput| command that
% \btx{} will not understand. 
% 
% \section{The Master File}
% The master file is a \btx{} bibliographic style file containing
% alternative coding depending on \dtx{} options. The options are
% selected when \dtx{} is run, either interactively or through a
% batch job. 
% 
% Suppose that one of the options is called \texttt{xyz}. Then the following
% alternatives are possible:
% \begin{quote}
% |%<xyz> | \em one line of coding
% \end{quote}
% \emph{includes} the single line of coding;
% \begin{quote}
% |%<!xyz> | \em one line of coding 
% \end{quote}
% \emph{excludes} the single line;
% \begin{quote}
% |%<*xyz> | \\
% \emph{several lines of coding}\\
% |%</xyz> | 
% \end{quote}
% \emph{includes} all the bracketed lines;
% \begin{quote}
% |%<*!xyz> | \\
% \emph{several lines of coding}\\
% |%</!xyz> | 
% \end{quote}
% \emph{excludes} all the bracketed lines.
% 
% Options may be logically combined: the symbol \verb!|! is a logical
% \textsf{or}, |&| a logical \textsf{and}, |!| a logical \textsf{not};
% parentheses \texttt{(} and \texttt{)} may be used to group options.
% 
% \subsection{Using with \dtx}
% In order to generate a true \btx{} style file with selected options from
% the master file, it is necessary to run a \dtx{} batch job.
% Suppose that the master file is named \texttt{master.mbs}, the
% resulting \btx{} style file is to be \texttt{silly.bst}, and the batch job
% file itself is called \texttt{silly.dbj}. To produce this with options, say,
% \texttt{xyz} and \texttt{abc}, the batch job would look something like:
% \begin{quote}\begin{verbatim}
% \def\batchfile{silly.dbj}
% \input docstrip
% 
% \preamble
% This is for Journal of Silly Results
% \endpreamble
% 
% \postamble
% End of customized bst file
% \endpostamble
% 
% \keepsilent
% 
% \generateFile{silly.bst}{f}{\from{master.mbs}{xyz,abc}}
% \end{verbatim}
% \end{quote}
% A preamble is not necessary, although it is advisable to include some
% statement about the application of the bibliographic style. A postamble
% \emph{is} vital, otherwise the default will add |\endinput| at the end
% of the file, something that \btx{} will not understand. The |\keepsilent|
% is optional and just suppresses \dtx{} output during processing.
% 
% \subsection{The Menu File}
% This program, \theprog, simplifies the creation of the batch job file. To
% do that, it needs information on the available options. This information
% must be stored in a special format, in the master file itself.
% Alternatively, that information may be extracted and stored in a file
% with the same root name but extension \texttt{.opt}. \textsl{This feature
% is not recommended since it can lead to inconsistencies!}
% The format of the menu information is illustrated below in 
% Section~\ref{sec:menu}.
% 
% In the master file, this information must be enclosed within \dtx{}
% options |%<*options>| \dots\ |%</options>| and \emph{must} be ended by an
% |\endoptions| command. It may also include any number of comments. 
% The rest of the file must be enclosed within |%<*!options>| \dots\
% |%</!options>| to exclude it when the menu information is extracted
% with \dtx.
% 
% A sample menu in the master file to select one or none of options 
% \texttt{xyz} \emph{or} \texttt{zyx} would look thus:
% \begin{quote}\begin{verbatim}
% %<*options>
% \mes{Select one of these}
% \optdef{f}{xyz}{Option forword}{to do forward stuff}
% \optdef{r}{zyx}{Option reverse}{to do reverse stuff}
% \optdef{*}{}{None of the above}{}
% \getans
% \endoptions
% %</options>
% %<*!options>
% . . . . . . 
% %</!options>
% \end{verbatim}
% \end{quote}
% An explanation of these commands is to be found in Section~\ref{sec:menu}.
% 
% The menu information may be extracted from the master file by means of
% \dtx{} and stored in a file with extension \texttt{.opt}. If this
% file is present, \theprog{} offers to read it instead of the master file,
% although this is \emph{not} recommended, as explained above.
% 
% \section{Running \protect\theprog}
% This is actually a \TeX{} program, although it will also run under \LaTeX.
% In that sense, it is like \dtx{} itself.
% Thus run the program with (something like)
% \begin{quote}\texttt{tex} \theprog\end{quote}
% 
% The program first asks for the name of the master file. This is
% the file containing all possible bibliographic style commands, with 
% \dtx{} options for selective output. A default name is offered, as well
% as a default extension (\texttt{.mbs}).
% 
% Next, the program asks for the name of the output file, the \texttt{.bst}
% file. The extension here is optional, defaulting to \texttt{.bst}. This name
% also determines the name of the batch job file, which will have the same
% root name with the extension \texttt{.dbj}, for the \emph{\dtx{} batch job}.
% 
% The actual interrogation then begins. All the information for the menus
% is contained in the master bibliographic style file.  The reason for this
% is that the menu information must conform to the available options in the
% master file, so it makes sense that one file should contain both. The
% master file is only read up to the |\endoptions| command.
% 
% Finally, the batch job file is closed, and the user is asked if it should
% be run.  If he does not take up this
% offer, or if he later edits the batch job, then it may be run manually
% with (something like)
% \begin{quote}\texttt{tex} \emph{bstname}\texttt{.dbj}\end{quote}
% 
% \section{The Menu Information\label{sec:menu}}
% The set of questions in the interrogation must fit the available
% options in the master file. For this reason, the menu information is
% contained in the master file itself. The program \theprog{} supplies the
% macros that are used in the menu file to simplify writing and processing
% menu information.
% 
% \DescribeMacro{\mes}
% To print a message to the terminal, use |\mes|\marg{text}. A new line
% may be forced within \emph{text} by means of |^^J|.
% 
% \DescribeMacro{\ask}
% To interrogate the user for a response, use |\ask{\|\emph{com}|}|\marg{text},
% which writes \emph{text} to the terminal, and puts the
% response in the command |\|\emph{com}. 
% 
% \DescribeMacro{\optdef}
% Almost all interrogations will consist of a list of mutually exclusive 
% options, one of which is the default. For each item in the list, one must
% specify the keyboard response that is to select it, the actual name of
% the \dtx{} option that realizes it, and two pieces of explanatory
% text. For example,
% \begin{quote}
% |\optdef{a}{abr}{Abbreviations}{of such words}|
% \end{quote}
% means that \texttt{abr} is the true \dtx{} option name that is
% selected by typing \texttt{a}. The two explanatory texts are written to the
% terminal immediately as part of the menu, but only the first text is
% echoed when the selection is made (for confirmation) and is also written
% to the batch job file (as comment).
%
% The default option must have the response |*|.
% 
% A menu is written to the terminal, first with a |\mes| command to state
% the subject matter, and then with a sequence of |\optdef| statements,
% each of which also writes the texts to the terminal. 
% \DescribeMacro{\getans}
% The response is then read in and processed with |\getans|, which writes
% the reply to the command |\ans| and writes the appropriate \dtx{}
% option to the batch job file. If the response does not correspond to any
% of those in the menu list, it is set to {\tt*}; if there is no {\tt*}
% in the list, then |\ans| is set to the last entry. The command |\ans|
% is still available afterwards for any extra testing that might be needed.
% 
% An example menu appears as follows:
% \begin{quote}\begin{verbatim}
% \mes{^^JJOURNAL VOLUME NUMBER:}
% \optdef{*}{}{Volume plain}{as vol(num)}
% \optdef{i}{vol-it}{Volume italic}%
%        {as {\string\em\space vol}(num)}
% \optdef{b}{vol-bf}{Volume bold}%
%       {as {\string\bf\space vol}(num)}
% \optdef{d}{vol-2bf}{Volume and number bold}%
%       {as {\string\bf\space vol(num)}}
% \getans
% \end{verbatim}
% \end{quote}
% 
% \section{More Complex Batch Jobs}
% Version 3.0 of \theprog{} allows the master file to define more
% sophisticated batch jobs, such as additional master files with their own
% options. This is made possible because the options are not written
% directly in the |\generateFile| command, as in earlier versions, but to a
% command |\MBopts|. The batch file then contains something like:
% \begin{quote}
% |\def\MBopts{\from|\marg{source.ext}|{%|\\
% \hspace*{1em}\emph{lines from menu session}\\
% | }}|\\
% |\generateFile|\marg{output.ext}|{f}{\MBopts}|
% \end{quote}
% 
% Normally the \emph{lines from menu session} contain just the \dtx{}
% options. However, the master file could add other things to the
% definition of |\MBopts|, even closing it and starting a new definition.
% It just has to make sure that the braces are balanced.
% 
% \DescribeMacro{\MBaskfile}
% A number a macros are provided, which are used by \theprog{} itself, to
% simplify making complex menus. To ask for the name of a file
% interactively,
% \begin{quote}
% |\MBaskfile|\marg{Prompting text}\parg{root.ext}\marg{io}|\|\emph{fname}
% \end{quote}
% may be given, where \emph{root.ext} is the default name of the file,
% \emph{io} is \texttt{i} (for input) if the file must already exist, and
% |\|\emph{fname} is the command that receives the file name. The root name
% will be in |\froot|, the extension in |\fext|.
% 
% \DescribeMacro{\wr}
% Text is written to the batch job file with
% \begin{quote}
% |\wr|\marg{text}
% \end{quote}
% Any commands in \emph{text} that are to be written literally must be
% preceded by |\string|. 
% 
% \DescribeMacro{\MBswitch}
% Since any braces in \emph{text} must be balanced, something special must
% be done to permit them to be printed as normal characters. The command
% |\MBswitch| accomplishes this; the parentheses \texttt{( )} replace |{ }|
% as the delimiters. This should always be given within |\begingroup| \dots
% |\endgroup|.
% 
% As an example, suppose the master file contains only half the coding for
% the \texttt{.bst} file, the other half being in one of several other
% master files. We must prompt for this second file, include it for its
% options, and make sure that |\MBopts| knows about it. The following code
% in the master file will do this.
% \begin{quote}
% |\MBaskfile{Name of second master file}(aa.mbs)i\xfile|\\
% |\begingroup\MBswitch|\\
% |\wr(\string\MBopta})|\\
% |\wr(\string\from{\xfile}{\string\MBoptb}})|\\
% |\wr(\string\def\string\MBopta{\pc)|\\
% |\endgroup|\\
% \emph{regular menu information for first file}\\
% |\begingroup\MBswitch|\\
% |\wr(}\string\def\string\MBoptb{\pc)|\\
% |\endgroup|\\
% |\input\xfile\relax|\\
% |\begingroup\MBswitch|\\
% |\wr({\pc)|\\
% |\endgroup|\\
% |\endoptions|
% \end{quote}
% 
% The resulting \texttt{.dbj} file contains
% \begin{quote}
% |\def\MBopts{\from{first.mbs}{%|\\
% |\MBopta}|\\
% |\from{second.mbs}{\MBoptb}}|\\
% |\def\MBopta{%|\\
% \emph{first set of options}\\
% |}\def\MBoptb{%|\\
% \emph{second set of options}\\
% |{%|\\
% |  }}|\\
% |\generateFile{sample.bst}{f}{\MBopts}|
% \end{quote}
% 
% \StopEventually{\PrintIndex\PrintChanges}
% 
% \section{Coding}
% This section presents and explains the actual coding of the macros.
% It is nested between |%<*program>| and |%</program>|, which
% are indicators to \dtx{} that this coding belongs to the program
% file.
%
% \subsection{Preliminaries}
% The first thing is to open up i/o devices for communicating with the
% terminal and files. (Some of this has been borrowed from \dtx{}.)
% The terminal input and output are |\ttyin| and |\ttyout|
% respectively, while the output file if |\outfile|.
%    \begin{macrocode}
%<*program>
\newwrite\outfile
\newread\ttyin
\newread\infile
\newwrite\ttyout
%    \end{macrocode}
% \begin{macro}{\mes}\begin{macro}{\wr}
% The two commands for outputting text are defined: |\mes| writes to the
% terminal while |\wr| writes to the output file.
%    \begin{macrocode}
\def\mes{\immediate\write\ttyout}
\def\wr#1{\immediate\write\outfile{#1}}
%    \end{macrocode}
% \end{macro}\end{macro}
% 
% To assist inserting new lines in the middle of text, define a newline
% symbol.
%    \begin{macrocode}
\newlinechar=`\^^J
%    \end{macrocode}
% 
% \begin{macro}{\MBswitch}
% \changes{3.0}{1995 Feb 5}{Add macro}
% There are times when we need to write a line of code to the output file
% with unbalanced braces in that line. (They are balanced in another line.)
% Such lines are written with |\wr{...}|. If the braces in the argument are
% not balanced, then there will be trouble. To get around this, change the
% category codes of the braces to `other' and let parentheses take their
% place. 
%    \begin{macrocode}
\def\MBswitch{\catcode`\{=12 \catcode`\}=12
              \catcode`\(=1 \catcode`\)=2\relax}
%    \end{macrocode}
% The way to employ this is as
% \begin{quote}\begin{verbatim}
% \begingroup\MBswitch
% \wr(..{..)
% \endgroup
% \end{verbatim}
% \end{quote}
% \end{macro}
%
% \begin{macro}{\ask}
% To get a response from the terminal, use |\ask|. However, there are some
% complications here. If only carriage-return is pressed, then the response
% command is equal to |\par|; for anything else, a typed-in text includes a
% trailing blank. We must test for |\par| and remove the blank if it is
% there.
%    \begin{macrocode}
\def\defpar{\par}
\def\remblk#1 @@{#1}
\def\ask#1#2{\mes{#2}\read\ttyin to #1\ifx#1\defpar\def#1{}\else
   \edef#1{\expandafter\remblk#1@@}\fi}
%    \end{macrocode}
% \end{macro}
% 
% \begin{macro}{\getroot}
% \begin{macro}{\getext}
% To parse the name of a file into root and extension, use commands
% |\getroot| and |\getext|.
%    \begin{macrocode}
\def\groot#1.#2@@{#1}
\def\getroot#1{\expandafter\groot#1.@@}
\def\gext#1.#2.#3@@{#2}
\def\getext#1{\expandafter\gext#1..@@}
%    \end{macrocode}
% \end{macro}\end{macro}
% 
% \begin{macro}{\MBaskfile}
% \changes{3.0}{1995 Feb 5}{Add macro to get a file name}
% Several times it is necessary to ask for a file name interactively, and
% maybe test if it exists. This might even be done in the \texttt{.mbs}
% file, so provide a macro to simplify this task. The syntax is
% \begin{quote}
% |\MBaskfile|\marg{Prompting text}\parg{root.ext}\marg{io}|\|\emph{fname}
% \end{quote}
% where \emph{root.ext} is the default name for the file sought, and
% |\|\emph{fname} is the command that contains the final file name. The
% commands |\froot| and |\fext| will contain the root and extensions of the
% file name, if they are needed for further parsing. If
% \emph{io}=\texttt{i} (for input), then the resulting file must already
% exist, else the macro loops again. If \emph{root} is blank, then only the
% extension is given as default, but a file root name must be entered.
%    \begin{macrocode}
\def\MBaskfile#1(#2.#3)#4#5{%
\loop
  \def\ans{#2.#3}
\if!#2!
 \if!#3!\ask{#5}{#1}\fi
  \ask{#5}{#1 (default extension=#3)}\else
  \ask{#5}{#1 (default=\ans)}
\fi
  \ifx#5\empty \edef#5{\ans}\fi
  \edef\froot{\getroot#5}
  \edef\fext{\getext#5}
  \ifx\fext\empty \def\fext{#3}\fi
  \edef#5{\froot.\fext}
\if#4i
  \def\temp{Cannot find file `#5'}
  \openin\infile#5\relax
  \ifeof\infile \def\ans{}\fi \closein\infile
\else
 \def\temp{There is no default}
 \ifx\froot\empty \def\ans{}\fi
\fi
  \ifx\ans\empty \mes{*** \temp}
\repeat}
%    \end{macrocode}
% \end{macro}
%
% \begin{macro}{\pc}\begin{macro}{\pcpc}\begin{macro}{\spsp}
% Now for some special commands to simplify outputting \% signs and double 
% spaces to the output file.
%    \begin{macrocode}
{\catcode`\%=12
 \gdef\pc{%}
 \gdef\pcpc{%% }
}
\def\spsp{\space\space}
%    \end{macrocode}
% \end{macro}\end{macro}\end{macro}
% 
% \begin{macro}{\Now}
% \changes{2.0}{1994 Jul 1}{Make \cmd{\today} output YYYY/MM/DD}
% In order to date-and-time-stamp the resulting batch job file, we need
% macros to produce the current date and time. (In \TeX{} there is no
% |\today| command.)
%    \begin{macrocode}
\newcount\hours
\newcount\minutes
\def\SetTime{\hours=\time
        \global\divide\hours by 60
        \minutes=\hours
        \multiply\minutes by 60
        \advance\minutes by-\time
        \global\multiply\minutes by-1 }
\SetTime
\def\now{\number\hours:\ifnum\minutes<10 0\fi\number\minutes}
\def\today{\number\year/\ifnum\month<10 0\fi\number\month
   /\ifnum\day<10 0\fi\number\day}
\def\Now{\today\space at \now}
%    \end{macrocode}
% \end{macro}
% 
% \subsection{Menu Macros}
% \begin{macro}{\optdef}
% For each menu, a general text is written with |\mes|, followed by a list
% of available options. The information that will be needed is
% \begin{enumerate}
% \item the response letter to select the option,
% \item the actual \dtx{} option name, as defined in the master
%   bibliographic style file,
% \item a piece of text that is printed in the menu list, to be echoed
%   in confirmation of the choice, and also to be written to batch job file
%   as a comment,
% \item a second piece of text that is only written to the menu, to enhance
%   the explanation.
% \end{enumerate}
% The true option name and the first piece of text are stored as commands
% prefixed by |\opt@| and |\txt@| respectively, followed by the response
% letter. Each option response letter is also stored in a list |\optlist|
% which is initialized to contain only a question mark. The commands 
% |\nxtopt| and |\rstopt| are used to extract the next and remaining
% options from the list.
%    \begin{macrocode}
\def\optdef#1#2#3#4{\expandafter\def\csname opt@#1\endcsname{#2}%
  \expandafter\def\csname txt@#1\endcsname{#3}%
  \edef\optlist{#1,\optlist}%
  \mes{(#1) #3\space #4}}

\def\optlist{?,}

\def\nxtopt#1,#2@@{#1} \def\rstopt#1,#2@@{#2}

%    \end{macrocode}
% \end{macro}
% 
% \begin{macro}{\getans}
% \changes{2.1}{1994 Dec 29}{Allow for \texttt{optlist} option}
% The user selection is read in with |\getans|, into the command |\ans|.
% It then processes the response by first checking if there is an option
% corresponding to it; if not, the response |\ans| is set to the default
% |*|. If no star response exists, then it takes the first entry in
% |\optlist| (the last one entered) as the default response.
% It then calls |\wropt| to write the necessary \dtx{} option
% and explanatory comment to the batch job file. Finally, it uses the
% option list |\optlist| to clear all the |\opt@| commands. This last step
% is necessary to avoid conflicts with previous menus: without it, a
% response that is not in the current list might however exist from an
% earlier menu.
%    \begin{macrocode}
\newif\ifsw
\def\getans{\ask{\ans}{\spsp Select:}
  \expandafter\ifx\csname opt@\ans\endcsname\relax \def\ans{*}\fi
  \expandafter\ifx\csname opt@\ans\endcsname\relax 
     \edef\ans{\expandafter\nxtopt\optlist@@}\fi
  \swtrue \loop
    \edef\temp{\expandafter\nxtopt\optlist@@}%
    \edef\optlist{\expandafter\rstopt\optlist@@}%
    \if\temp?\swfalse\else
      \if\temp\ans\wropt\ans
%<optlist>          \else\wrxopt\temp
      \fi
      \expandafter\let\csname opt@\temp\endcsname\relax
    \fi
  \ifsw \repeat
  \def\optlist{?,}%
%<optlist>  \wr{\pc--------------------}%
  }
%    \end{macrocode}
% \end{macro}
% 
% \begin{macro}{\wropt}
% \changes{2.1}{1994 Dec 29}{Change \cs{temp} to \cs{tempx}}
% The actual outputting of the option command to the batch job file is done
% by |\wropt|. It tests if the option name is blank (a default in the
% master bibliographic style, which need not be the menu default), writes
% out the option name, if present, and adds the explanatory comment. The
% separation character |\sep| is initially empty, and is set to a comma
% after the first option has been written.
%    \begin{macrocode}
\def\wropt#1{\edef\tempx{\csname opt@#1\endcsname}\if!\tempx!
  \wr{\spsp\spsp\pc: (def) \csname txt@#1\endcsname}\else
  \wr{\spsp\sep\csname opt@#1\endcsname\pc: \csname txt@#1\endcsname}
    \def\sep{,}\fi
  \mes{\spsp You have selected: \csname txt@#1\endcsname}}
%    \end{macrocode}
% \end{macro}
% 
% \begin{macro}{\wrxopt}
% \changes{2.1}{1994 Dec 29}{Add macro}
% A special request from Frank Mittelbach asks if a list of unused options
% cannot be added to the batch job file, to assist editing it by hand. In
% this way, one knows what the \dtx{} are immediately without having to
% search for them in the \texttt{.mbs} documentation. 
% 
% This is relatively easy to do, so I have added it, but only as an option.
% (How that word is overused in this business!) I mean, normally this full
% list of options is turned off, but if one extracts \theprog\texttt{.tex}
% from \theprog\texttt{.dtx} with the \texttt{optlist} option in addition
% to \texttt{program} then it will be turned on. It requires the macro
% |\wrxopt| that parallels |\wropt|, except that the options are listed in
% the batch job file commented out.
%    \begin{macrocode}
%<*optlist>
\def\wrxopt#1{\edef\tempx{\csname opt@#1\endcsname}\if!\tempx!
  \wr{\pc\spsp\pc(def) \csname txt@#1\endcsname}\else
  \wr{\pc\spsp\sep\csname opt@#1\endcsname\pc: \csname txt@#1\endcsname}
    \def\sep{,}\fi}
%</optlist>
%    \end{macrocode}
% One problem with this feature is that only those options are listed that
% were offered. Sometimes the offered options depend on previous ones, so
% that the list is not really complete. Because of this danger, I do not
% want to make this feature standard, yet.
% \end{macro}
% 
% \subsection{Initial Messages}
% The program can now start working. It first introduces itself and asks if
% the user wants an explanation of how the menus work.
%    \begin{macrocode}
\mes{***********************************^^J%
     * This is Make Bibliography Style *^^J%
     ***********************************^^J%
     It makes up a docstrip batch job to produce^^J%
     a customized .bst file for running with BibTeX}

\ask{\yn}{Do you want a description of the usage? (NO)}

\if!\yn!\else\if\yn n\else\if\yn N\else
\mes{In the interactive dialogue that follows,^^J%
     you will be presented with a series of menus.^^J%
     In each case, one answer is the default, marked as (*),^^J%
     and a mere carriage-return is sufficient to select it.^^J%
     (If there is no * choice, then the default is the last choice.)^^J%
     For the other choices, a letter is indicated^^J%
     in brackets for selecting that option. If you select^^J%
     a letter not in the list, default is taken.^^J^^J%
     The final output is a file containing a batch job^^J%
     which may be (La)TeXed to produce the desired BibTeX^^J%
     bibliography style file. The batch job may be edited^^J%
     to make minor changes, rather than running this program^^J%
     once again.}
\fi\fi\fi
%    \end{macrocode}
% 
% Ask for the name of the master bibliographic style file,
% suggesting a default name. Test if the file exist (argument \texttt{i}).
% The name of the master file is split up into root and extension. 
% \changes{3.0}{1995 Mar 15}{Default master file now \texttt{merlin.mbs}}
%    \begin{macrocode}
\MBaskfile{^^JEnter the name of the MASTER file}(merlin.mbs)i\mfile
\let\mroot=\froot
\let\mext=\fext
%    \end{macrocode}
%
% Originally, I intended the menu information to be in an \texttt{.opt}
% file, but this is dangerous: that file may not be consistent with the
% master. So now, issue a warning if an \texttt{.opt} file exists, 
% substituting it only if explicitly requested. (This is useful for me
% when testing changes to \theprog{} and I only want a short menu.)
%    \begin{macrocode}
\edef\temp{\mroot.opt}
\openin\infile\temp\relax
\let\mnext=\mext
\ifeof\infile\else
  \ask{\yn}{** Warning: a file `\temp' also exists^^J
       \spsp Shall I read it for the menu information? (NO)^^J
       \spsp (Answer `yes' only if you really know what you are doing)}
\if\yn y\def\mnext{opt}\else\if\yn Y\def\mnext{opt}\fi\fi
\mes{Menu information read from `\mroot.\mnext'}
\fi
\closein\infile
%    \end{macrocode}
% 
% Next, the name of the output \texttt{.bst} file is asked for. Here there is
% to be no default for the root part, although the extension defaults to
% \texttt{.bst}.
%    \begin{macrocode}
\MBaskfile{^^JName of the final OUTPUT .bst file?}(.bst)o\ofile
\let\oroot=\froot
\let\oext=\fext
%    \end{macrocode}
% 
% A comment line of text is asked for. This will go into the preamble of
% the final \texttt{.bst} file and should describe the nature of the
% bibliographic style, i.e., for which journal(s) it is meant to apply.
%    \begin{macrocode}
\ask{\ans}{^^JGive a comment line to include in the style file.^^J%
           Something like for which journals it is applicable.}
%    \end{macrocode}
% 
% \changes{1.1}{1994 May 25}{The \dtx{} driver has extension \texttt{.dbj}
%    instead of \texttt{.drv}}
% The output batch job file is to have the same root name as the output
% file, but with the extension \texttt{.dbj}, for \emph{\dtx{} batch job}. 
% This file is opened and the initial contents are written.
%    \begin{macrocode}
\immediate\openout\outfile\oroot.dbj
\wr{\pcpc Driver file to produce \oroot.\oext\space from \mroot.\mext}
\wr{\pcpc Generated with \filename, version \fileversion\space (\filedate)}
\wr{\pcpc Produced on \Now}
\wr{\pcpc}
\wr{\string\def\string\batchfile{\oroot.dbj}}
\wr{\string\input\space docstrip}
\wr{}
\wr{\string\preamble}
\wr{----------------------------------------}
\wr{*** \ans\space ***}
\wr{}
\wr{\string\endpreamble}
\wr{}
\wr{\string\postamble}
\wr{End of customized bst file}
\wr{\string\endpostamble}
\wr{}
\wr{\string\keepsilent}
\wr{}
%    \end{macrocode}
% \changes{3.0}{1995 Feb 5}{Options from master file written to control
%    sequence \cs{MBopts} instead of directly into \cs{generateFile}}
% The options will be written to the output file during the interrogation
% when the master file is input. These options are stored in |\MBopts|.
%
% Note: it is necessary to change the catagory codes of |{| and |}|
% temporarily, and to find substitutes, so that mismatched curly braces
% could be included in the output text. The same thing is done again at the
% end to close the braces finally. This is done with |\MBswitch|.
%    \begin{macrocode}
\begingroup\MBswitch
\wr(\string\def\string\MBopts{\string\from{\mroot.\mext}{\pc)
\endgroup
%    \end{macrocode}
% 
% Now each selected option is written on a single line.
% 
% \subsection{The Interrogation}
% \changes{2.1}{1995 Jan 2}{Get menu info from master file, not \texttt{.opt}
%   file.}
% The menu information is read in from the master file, or from a file
% with extension \texttt{.opt}, but only if one has explicitly requested
% this. (This is expert stuff; the \texttt{.opt} files should be avoided
% since they might not be up-to-date. Previously they were the default,
% but this has been changed in version~2.1 to avoid confusion.)
%    \begin{macrocode}
\def\sep{}

\edef\temp{\mroot.\mnext}
\let\endoptions=\endinput
\input\temp
%    \end{macrocode}
% Note that it is necessary to equate |\endoptions| to |\endinput| in 
% case the master file is read in. An |\endinput| command in the master
% file would interfere with the \dtx{} operation, but this indirect
% method gets around that problem.
%
% \section{Closing the Output File}
% The output file is closed by writing the final line that closes the
% braces that were opened at the beginning. To this end, the catagory codes
% of |{| and |}| must be temporarily altered, as before.
%    \begin{macrocode}
\begingroup\MBswitch
\wr(\spsp}})
\endgroup
%    \end{macrocode}
%
% Now write the line that processes the options stored in |\MBopts|.
% The batch job file is finished and may be closed.
%    \begin{macrocode}
\wr{\string\generateFile{\oroot.\oext}{f}{\string\MBopts}}

\immediate\closeout\outfile
\mes{^^JFinished!!^^J%
     Batch job written to file `\oroot.dbj'}
%    \end{macrocode}
% 
% The batch job may now be run. It is only necessary to input the file.
% However, the inputting should not occur with a group or within an |\if| 
% \dots\ |\fi| clause. Furthermore, under \LaTeX{}, the |\end| command causes
% problems, because it has been redefined; the command |\@@end| contains the
% original |\end|.
%    \begin{macrocode}
\def\ofile{\oroot.dbj}
\ask{\yn}{Shall I now run this batch job? (NO)}
\def\temp{\relax}
\if!\yn!\else\if\yn n\else\if\yn N\else
\def\temp{\input\ofile}\fi\fi\fi
{\catcode`\@=11 \ifx\@@end\undefined\else
  \global\let\end=\@@end\fi}
\temp 
\end
%</program>
%    \end{macrocode}
%
% \Finale
