#!/usr/bin/env perl
# $Id: xindy.pl,v 1.18 2011/01/18 22:18:29 jschrod Exp $
#------------------------------------------------------------
# (history at end)

=head1 NAME

xindy - create sorted and tagged index from raw index

=head1 SYNOPSIS

 xindy [-V?h] [-qv] [-d magic] [-o outfile.ind] [-t log] \
       [-L lang] [-C codepage] [-M module] [-I input] \
       [--interactive] [--mem-file=xindy.mem] \
       [idx0 idx1 ...]

=head2 GNU-Style Long Options for Short Options:

 -V / --version
 -? / -h / --help
 -q / --quiet
 -v / --verbose
 -d / --debug          (multiple times)
 -o / --out-file
 -t / --log-file
 -L / --language
 -C / --codepage
 -M / --module         (multiple times)
 -I / --input-markup   (supported: latex, xelatex, omega, xindy)


=head1 DESCRIPTION

B<xindy> is the formatter-indepedent command of xindy, the flexible
indexing system. It takes a raw index as input, and produces a merged,
sorted and tagged index. Merging, sorting, and tagging is controlled
by xindy style files.

Files with the raw index are passed as arguments. If no arguments are
passed, the raw index will be read from standard input.

B<xindy> is completely described in its manual that you will find on
its Web Site, http://www.xindy.org/. A good introductionary
description appears in the indexing chapter of the LaTeX Companion (2nd ed.)

If you want to produce an index for LaTeX documents, the command
texindy(1) is probably more of interest for you. It is a wrapper for
B<xindy> that turns on many LaTeX conventions by default.


=head1 OPTIONS

=over

=item C<--version> / B<-V>

output version numbers of all relevant components and exit.

=item C<--help> / B<-h> / B<-?>

output usage message with options explanation.

=item C<--quiet> / B<-q>

Don't output progress messages. Output only error messages.

=item C<--verbose> / B<-v>

Output verbose progress messages.

=item C<--debug> I<magic> / B<-d> I<magic>

Output debug messages, this option may be specified multiple times.
I<magic> determines what is output:

 magic          remark
 ------------------------------------------------------------
 script         internal progress messages of driver scripts
 keep_tmpfiles  don't discard temporary files
 markup         output markup trace, as explained in xindy manual
 level=n        log level, n is 0 (default), 1, 2, or 3

=item C<--out-file> F<outfile.ind> / B<-o> F<outfile.ind>

Output index to file F<outfile.ind>. If this option is not passed, the
name of the output file is the base name of the first argument and the
file extension F<ind>. If the raw index is read from standard input,
this option is mandatory.

=item C<--log-file> F<log.ilg> / B<-t> F<log.ilg>

Output log messages to file F<log.ilg>. These log messages are
independent from the progress messages that you can influence with
C<--debug> or C<--verbose>.

=item C<--language> I<lang> / B<-L> I<lang>

The index is sorted according to the rules of language I<lang>. These
rules are encoded in a xindy module created by I<make-rules>.

If no input encoding is specified via C<--codepage> or enforced by
input markup, a xindy module for that language is searched with a
latin, a cp, an iso, ascii, or utf8 encoding, in that order.

Language modules are either placed in the F<lang> or in the
F<contrib/lang> sub-directory of the modules base directory.

=item C<--codepage> I<enc> / B<-C> I<enc>

The raw input is in input encoding I<enc>. This information is used to
select the correct xindy sort module and output encoding of letter
group headings.

When C<xelatex> or C<omega> input markup is used, C<utf8> is always
used as codepage, then this option is ignored.

If raw input is in LICR, texindy(1) should be used instead of
xindy(1). It will activate a mapping of I<inputenc> encoding for
C<latex> input markup to the chosen raw input codepage.

=item C<--module> I<module> / B<-M> I<module>

Load the xindy module F<module.xdy>. This option may be specified
multiple times. The modules are searched in the xindy search path that
can be changed with the environment variable C<XINDY_SEARCHPATH>.

=item C<--input-markup> I<input> / B<-I> I<input>

Specifies the input markup of the raw index. Supported values for
I<input> are C<latex>, C<xelatex>, C<omega>, and C<xindy>.

C<latex> and C<xelatex> input markup is the one that is emitted by
default from the LaTeX kernel, or by the C<index> macro package of
David Jones. ^^-notation of single byte characters is supported.
Remapping of LICR-encoded characters is not done; use texindy(1) for
that. Use input markup C<latex> if you use standard LaTeX or pdfLaTeX
and use input markup C<xelatex> if you use XeLaTeX or LuaLaTeX.

C<omega> input markup is like C<latex> input markup, but with Omega's
^^-notation as encoding for non-ASCII characters.

C<xindy> input markup is specified in the xindy manual.

=item C<--interactive>

Start xindy in interactive mode. You will be in a xindy read-eval-loop
where xindy language expressions are read and evaluated interactively.

=item C<--mem-file> I<xindy.mem>

This option is only usable for developers or in very rare situations.
The compiled xindy kernel is stored in a so-called I<memory file>,
canonically named F<xindy.mem>, and located in the xindy library
directory. This option allows to use another xindy kernel.

=back


=head1 SUPPORTED LANGUAGES / CODEPAGES

The following languages are supported:

=head2 Latin scripts

 albanian      gypsy             portuguese
 croatian      hausa		 romanian
 czech	       hungarian 	 russian-iso
 danish	       icelandic	 slovak-small
 english       italian		 slovak-large
 esperanto     kurdish-bedirxan  slovenian
 estonian      kurdish-turkish	 spanish-modern
 finnish       latin		 spanish-traditional
 french	       latvian		 swedish
 general       lithuanian	 turkish
 german-din    lower-sorbian	 upper-sorbian
 german-duden  norwegian	 vietnamese
 greek-iso     polish

German recognizes two different sorting schemes to handle umlauts:
normally, C<ä> is sorted like C<ae>, but in phone books or
dictionaries, it is sorted like C<a>. The first scheme is known as
I<DIN order>, the second as I<Duden order>.

C<*-iso> language names assume that the raw index entries are in ISO
8859-9 encoding.

C<gypsy> is a northern Russian dialect.

=head2 Cyrillic scripts

 belarusian    mongolian  	 serbian
 bulgarian     russian    	 ukrainian
 macedonian

=head2 Other scripts

 greek         klingon

=head2 Available Codepages

This is not yet written. You can look them up in your xindy
distribution, in the F<modules/lang/language/> directory (where
I<language> is your language). They are named
F<variant-codepage-lang.xdy>, where F<variant-> is most often empty
(for german, it's C<din5007> and C<duden>; for spanish, it's C<modern>
and C<traditional>, etc.)

 < Describe available codepages for each language >

 < Describe relevance of codepages (as internal representation) for
   LaTeX inputenc >



=head1 ENVIRONMENT

=over

=item C<XINDY_SEARCHPATH>

A list of directories where the xindy modules are searched in. No
subtree searching is done (as in TDS-conformant TeX).

If this environment variable is not set, the default is used:
C<.:>I<modules_dir>C<:>I<modules_dir>C</base>. I<modules_dir> is
determined at run time, relative to the B<xindy> command location:
Either it's F<../modules>, that's the case for F<opt>-installations.
Or it's F<../lib/xindy/modules>, that's the case for
F<usr>-installations.

=item C<XINDY_LIBDIR>

Library directory where F<xindy.mem> is located.

The modules directory may be a subdirectory, too.

=back


=head1 COMPATIBILITY TO MAKEINDEX

B<xindy> does not claim to be completely compatible with MakeIndex,
that would prevent some of its enhancements. That said, we strive to
deliver as much compatibility as possible. The most important
incompatibilities are

=over

=item *

For raw index entries in LaTeX syntax, C<\index{aaa|bbb}> is
interpreted differently. For MakeIndex C<bbb> is markup that is output
as a LaTeX tag for this page number. For B<xindy>, this is a location
attribute, an abstract identifier that will be later associated with
markup that should be output for that attribute.

For straight-forward usage, when C<bbb> is C<textbf> or similar, we
supply location attribute definitions that mimic MakeIndex's
behaviour.

For more complex usage, when C<bbb> is not an identifier, no such
compatibility definitions exist and may also not been created with
current B<xindy>. In particular, this means that by default the LaTeX
package C<hyperref> will create raw index files that cannot be
processed with B<xindy>. This is not a bug, this is the unfortunate
result of an intented incompatibility. It is currently not possible to
get both hyperref's index links and use B<xindy>.

A similar situation is reported to exist for the C<memoir> LaTeX
class.

Programmers who know Common Lisp and Lex and want to work on a remedy
should please contact the author.

=item *

If you have an index rage and a location attribute, e.g.,
C<\index{key\(attr}> starts the range, one needs (1) to specify that
attribute in the range closing entry as well (i.e., as
C<\index{key\)attr}>) and (2) one needs to declare the index attribute
in an B<xindy> style file.

MakeIndex will output the markup C<\attr{page1--page2}> for such a
construct. This is not possible to achieve in B<xindy>, output will be
C<\attrMarkup{page1}--\attrMarkup{page2}>. (This is actually
considered a bug, but not a high priority one.)

The difference between MakeIndex page number tags and B<xindy>
location attributes was already explained in the previous item.

=item *

The MakeIndex compatibility definitions support only the default raw
index syntax and markup definition. It is not possible to configure
raw index parsing or use a MakeIndex style file to describe output
markup.

=back


=head1 KNOWN ISSUES

Option B<-q> also prevents output of error messages. Error messages
should be output on stderr, progress messages on stdout.

There should be a way to output the final index to stdout. This would
imply B<-q>, of course.

LaTeX raw index parsing should be configurable.

Codepage C<utf8> should be supported for all languages, and should be
used as internal codepage for LaTeX inputenc re-encoding.


=head1 SEE ALSO

texindy(1),
tex2xindy(1)


=head1 AUTHOR

Joachim Schrod


=head1 LEGALESE

Copyright (c) 2004-2014 by Joachim Schrod.

B<xindy> is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by the
Free Software Foundation; either version 2 of the License, or (at your
option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

=for Emacs
# '

=cut


use strict;
use English qw(-no_match_vars);

our $VERSION = sprintf "%d.%02d", q$Revision: 1.18 $ =~ /: (\d+)\.(\d+)/ ;


# Used modules.

use Cwd;
use File::Basename;
use File::Spec;
use File::Temp qw(tempfile tmpnam);
use Getopt::Long qw(:config bundling);
use POSIX qw(uname);


# Determine environment. Where is our library directory, and our modules?

our $is_TL = ( '@is_TL@' eq 'yes' );
our $is_w32 = ( $OSNAME =~ /^MSWin/i ) ;
our $path_sep = ( $is_w32 ? ';' : ':' ) ;
our $is_windows = ( $is_w32 || $OSNAME eq 'cygwin' ) ;
our $clisp = ( $is_windows ? 'clisp.exe' : 'clisp' ) ;
our $real_cmd = Cwd::realpath($0);
our $cmd_dir = dirname($real_cmd);
our $cmd = basename($0);

our ($lib_dir, $modules_dir);

# xindy-lisp.exe for Windows seems to be unable to interpret the short-name
# format which is a default for the variables TEMP and TMP in Windows OS.
# As a workaround, we create temporary files in the current directory
# in xindy on Windows.

if ( $is_w32 ) {
use Env qw(TMPDIR);
Env::import();
$TMPDIR = ".";
}

# We have different installation structures for TeX-Live and a
# standalone installation. In TeX-Live, the user command is a symlink
# in some bin directory, and the actual script is in the library
# directory where both memory image and modules live as well.
# Standalone installations come in /usr or /opt variants, memory
# images are located in a lib directory, modules are located in a
# share directory.
#
# FIXME: In standalone installations, modules are still placed in lib
# directory. This is not conformant to FHS.

if ( $is_TL ) { # TeX Live and MikTeX

    $modules_dir = Cwd::realpath("$cmd_dir/../../xindy/modules");
    die "$cmd: Cannot locate xindy modules directory"  unless -d $modules_dir;

    if ( $is_w32 ) {
       if ( -d "$cmd_dir/../../../bin/win32" ) {	# TeX Live
	   $cmd_dir = "$cmd_dir/../../../bin/win32";
       } elsif ( -d "$cmd_dir/../../miktex/bin" ) {	# MikTeX
	   $cmd_dir = "$cmd_dir/../../miktex/bin";
       } else {
	   die "$cmd: Cannot locate bin directory";
       }
    } else {
	die "$cmd: not a symlink as required for TeX Live"  unless -l $0;
	# Follow symlinks and determine $cmd_dir such that
	# $cmd_dir/xindy -> $r0 = XINDY_SCRIPTDIR/xindy.pl
	# I.e., it determines the directory with the last symbolic link; the
	# one that points to a real file. That's the directory with the binary
	# files (Lisp executable and memory file).
	$real_cmd = $0;
	while (-l $real_cmd) {
	    $cmd_dir = dirname($real_cmd);
	    $real_cmd = readlink($real_cmd);
	    # \ directory separator may happen on Cygwin.
	    $real_cmd = "$cmd_dir/$real_cmd"  unless $real_cmd =~ m,^[\\/],; # relative link
	}
    }

    # library directory
    $lib_dir = $cmd_dir;

    # clisp runtime
    my $xindy_run = ( $is_windows ?
		      "$lib_dir/xindy-lisp.exe" : "$lib_dir/xindy.run" );
    $clisp = $xindy_run  if -e $xindy_run;

} else { # standalone installation

    # library directory
    if ( $ENV{XINDY_LIBDIR} ) {
	$lib_dir = $ENV{XINDY_LIBDIR};
    } elsif ( '@libdir@' ne '@libdir' . '@' ) { # GNU configure at work?
	if ( -d '@libdir@/xindy' ) {	# /usr style
	    $lib_dir = '@libdir@/xindy';
	} else {
	    $lib_dir = '@libdir@'; # /opt style
	}
    } elsif ( -f "$cmd_dir/../lib/xindy.mem" ) { # /opt style
	$lib_dir = "$cmd_dir/../lib";
    } elsif ( -d "$cmd_dir/../lib/xindy" ) { # /usr style
	$lib_dir = "$cmd_dir/../lib/xindy";
    } else {
	die "$cmd: Cannot locate xindy library directory";
    }

    # modules directory
    if ( -d "$cmd_dir/../modules" ) {	# /opt style
	$modules_dir = "$cmd_dir/../modules";
    } elsif ( -d "$lib_dir/modules" ) {	# /usr style
	$modules_dir = "$lib_dir/modules";
    } else {
	die "$cmd: Cannot locate xindy modules directory";
    }

} # determine environment


# Check arguments, store them in proper variables.

sub usage ( ;$ )
{
    my $exit_code = shift;
    $exit_code += 0;			# turn undef into 0
    my $out = ( $exit_code ? *STDERR : *STDOUT );
    print $out <<_EOT_

usage: $cmd [-V?h] [-qv] [-d magic] [-o outfile.ind] [-t log] \\
            [-L lang] [-C codepage] [-M module] [-I input] \\
            [--interactive] [--mem-file xindy.mem] \\
	    [idx0 idx1 ...]

GNU-STYLE LONG OPTIONS FOR SHORT OPTIONS:

 -V / --version
 -? / -h / --help
 -q / --quiet
 -v / --verbose
 -d / --debug          (multiple times)
                       (supported: script, keep_tmpfiles, markup, level=n)
 -o / --out-file
 -t / --log-file
 -L / --language
 -C / --codepage
 -M / --module         (multiple times)
 -I / --input-markup   (supported: latex, xelatex, omega, xindy)

_EOT_
  ;
    exit ($exit_code);
}

our ($quiet, $verbose, %debug,
     $outfile, $logfile, $language, @codepages, @modules, $input_markup,
     $interactive, $mem_file);
$input_markup = 'latex';
$mem_file = "$lib_dir/xindy.mem";

my @orig_argv = @ARGV;
parse_options();


# Support universal binary on Mac OS X.

if ( $OSNAME eq 'darwin'  &&  ! -e $mem_file ) {
    my @uname = POSIX::uname();
    if ( $uname[4] eq 'Power Macintosh' ) {
	$mem_file = "$lib_dir/xindy-ppc.mem";
    } else {
	$mem_file = "$lib_dir/xindy-i386.mem";
    }
}
die "$cmd: Cannot locate $mem_file"  unless -e $mem_file;


# This script creates temporary files. Whenever a file is created, its
# name is added to @temp_files. In an END handler, the temporary files
# are deleted. Signal handlers are set up to get proper program
# termination on user-induced signals.

our @temp_files = ();
handle_signals();
END {
    unlink (@temp_files)  if ( @temp_files  &&  ! $debug{keep_tmpfiles} );
}


# Raw index handling: xindy is not able (yet?) to handle arguments
# Perl-style, so we do it instead. We gather the raw index in a
# temporary file. We also process it by the filter program it if
# wanted. Signal handlers will discard temporary files if necessary.

our $raw_index = File::Spec->devnull;
unless ( $interactive ) {
    for my $f ( @ARGV ) {
	die "$cmd: input file $f does not exist"  unless -f $f;
    }
    $raw_index = create_raw_index();	# processes @ARGV
    my $filter_cmd = '';
    if ( $input_markup =~ /latex$/ ) {
	$filter_cmd = "$cmd_dir/tex2xindy";
    } elsif ( $input_markup eq 'omega' ) {
	$filter_cmd = "$cmd_dir/tex2xindy -o";
    }
    $raw_index = filter_index ($filter_cmd, $raw_index)
      if $filter_cmd;
}


# Execution: Create xindy start expression and call it.

my $xindy_expression = xindy_expression(); # accesses global option vars
my $exit_code = call_xindy ($mem_file, $xindy_expression);


# Finished: exit, clean up in END handler.

exit ($exit_code);


# ------------------------------------------------------------


sub parse_options() {

    my (@debug);
    GetOptions(
		'version|V'          => sub { output_version(0); },
		'internal-version'   => sub { output_version(1); },
		'help|h|?'           => \&usage,
		'quiet|q'            => \$quiet,
		'verbose|v'          => \$verbose,
		'debug|d=s'          => \@debug,
		'out-file|o=s'       => \$outfile,
		'log-file|t=s'       => \$logfile,
		'language|L=s'       => \$language,
		'codepage|C=s'       => \@codepages,
		'module|M=s'         => \@modules,
		'input-markup|I=s'   => \$input_markup,
		'interactive'        => \$interactive,
		'mem-file=s'         => \$mem_file,
	      )
      or  usage(1);

    # Debug option values are easier to test in a hash. Clean up trace
    # level options, too.
    %debug = map { $_ => 1 } @debug;
    my @trace_level = grep /^level=/, @debug;
    if ( @trace_level > 1 ) {
	print STDERR "You can only specify one trace level.\n\n";
	exit (1);
    }
    delete $debug{$trace_level[0]};
    $trace_level[0] =~ s/^level=// ;
    $debug{trace_level} = $trace_level[0];

    # Check for unsupported debug option values.
    my %debug_check = %debug;
    foreach my $magic ( qw(script keep_tmpfiles markup trace_level) ) {
	delete $debug_check{$magic};
    }
    if ( %debug_check ) {
	my @magic = keys(%debug_check);
	print STDERR "Unsupported argument for --debug: @magic\n";
	usage(1);
    }

    # Script debugging implies running it verbose and not quiet.
    if ( $debug{script} ) {
	$verbose = 1;
	$quiet = 0;
    }

    # Default for the output file: first argument, with extension replaced
    # by ".ind".
    unless ( $outfile  ||  $interactive ) {
	if ( @ARGV == 0 ) {
	    print STDERR
"You need to specify --out-file if the raw index is read from standard input.\n";
	    usage(1);
	}
	my ($name, $path, $suffix) = fileparse ($ARGV[0], '\.[^\.]+');
	$outfile = "$path$name.ind";
    }

    # FIXME: xindy wants a log file. Really?
    $logfile = File::Spec->devnull  unless $logfile;

    # Modules fixup: If they have no .xdy suffix, they get one.
    @modules = map { /\.xdy$/ ? $_ : "$_.xdy" } @modules;

    # Check that the input markup is known.
    # omega markup implies codepage utf8.
    if ( $input_markup  &&
	 $input_markup ne 'latex'  &&  $input_markup ne 'xelatex'  &&
	 $input_markup ne 'omega'  &&  $input_markup ne 'xindy' ) {
	print STDERR "Unsupported input markup $input_markup.\n";
	usage(1);
    }
    if ( $input_markup eq 'xelatex'  ||  $input_markup eq 'omega' ) {
	@codepages = qw(utf8);
    }

}



#
# SIGNAL HANDLING
#
# FIXME: This is not good enough. We also need to kill subprocesses,
# i.e., filter or xindy, if they are running.

# Our signal handler function just exits. Temporary files are deleted
# by the END section above. Actually, the exit code looses the
# information about the received signal, that's not good but shouldn't
# hurt either...

sub signal_exit() {
    exit (2);
}

sub handle_signals () {
    $SIG{'HUP'}  = \&signal_exit; # 1
    $SIG{'INT'}  = \&signal_exit; # 2
    $SIG{'QUIT'} = \&signal_exit; # 3
    $SIG{'TERM'} = \&signal_exit; # 15
}



#
# CREATION OF RAW XINDY INDEX
#

# Handle input files Perl-style. Returns file name that contains
# concatenated input file contents.

sub create_raw_index () {
    my ($output, $outfile) = tempfile();
    push (@temp_files, $outfile);
    $outfile=quotify($outfile);
    while ( <> ) {
	print $output $_;
    }
    close ($output);
    print "concatenated xindy input file: $outfile\n"  if $debug{script};
    return $outfile;
}


# Run a filter over raw index. Returns file name with filtered raw
# index, supposed to be in xindy input format.
#
# We assume the file names to be safe from shell meta characters since
# they were computed by File::Temp.

sub filter_index ( $$ ) {
    my ($filter, $input) = @_;
    my $output = tmpnam();
    push (@temp_files, $output);
    $output=quotify($output);
    print "Running filter: $filter <$input >$output\n"  if $verbose;
    system "$filter <$input >$output";
    print "filtered xindy input file: $output\n"  if $debug{script};
    return $output;
}



#
# XINDY EXECUTION
#

# Construct final xindy expression, from options.

sub xindy_expression () {
    my ($logging, $tracing, $trace_level, $searchpath);

    # Determine language module of make-rules framework. Part of the
    # complexity below is from compatibility with the TLC2
    # description. We need to support the language names listed there,
    # even though they are not current. In addition, the codepage
    # option was introduced later and we need to guess it. This
    # guesswork will often be wrong, sadly.
    #
    # FIXME: I didn't see all languages. What's on with gypsy and
    # hausa?
    if ( $language ) {
	# If there is no language directory, this might be a variant.
	# Language names and variants are separated by hyphens. The
	# variant name "din" is an abbreviation for "din5007". The
	# variant name "iso" is ignored, that is actually a codepage
	# name.
	#
	# FIXME: Or is "iso" the variant "translit"?!
	my @lang_base_dirs = ("$modules_dir/contrib/lang", "$modules_dir/lang");
	my ($lang_dir, $variant);
	foreach my $ld ( @lang_base_dirs ) {
	    if ( -d "$ld/$language" ) {
		$lang_dir = "$ld/$language";
		last;
	    } else {
		$language =~ /^([^-]*)-(.*)/ ; # language name ends with 1st hyphen
		if ( $2 && -d "$ld/$1" ) { # $2 is not set if the regex didn't match
		    $language = $1;
		    $lang_dir = "$ld/$language";
		    $variant = "$2-"  unless ( $2 eq 'iso' );
		    $variant eq 'din-'  and  $variant = 'din5007-';
		    last;
		}
	    }
	}
	# Let's guess the codepage. We take any that starts with
	# "latin", "cp", "iso8859", "ascii", or "utf8".
	@codepages = qw(latin cp iso8859 ascii utf8)  unless @codepages;
	my @styles;
	foreach my $cp ( @codepages ) {
	    @styles = glob("$lang_dir/$variant$cp*-lang.xdy");
	    last  if @styles;
	}
	unless ( @styles ) {
	    print STDERR "Cannot locate xindy module for language $language";
	    print STDERR " in codepage $codepages[0]"  if ( @codepages == 1 );
	    print STDERR ".\n";
	    exit (1);
	}
	# Extract language module name: It's the relative part after
	# the module directory. Put it at the front of the list of
	# needed modules. It's important that the language module is
	# loaded first, it defines the sort rulesets, and subsequent
	# modules shall be able to add sort rules.
	unshift (@modules, substr($styles[0], length("$modules_dir/")));
	print "Found language module $styles[0]\n"  if $debug{script};
    }

    # If there is more than one xindy module, construct a style file.
    # This is bad, of course; xindy should handle a list of style
    # files itself.
    my $style_file = $modules[0];	# will be undef if @modules is not set
    if ( @modules > 1 ) {
	my $sf;
	($sf, $style_file) = tempfile();
	push (@temp_files, $style_file);
	$style_file=quotify($style_file);
	foreach my $module ( @modules ) {
	    print $sf "(require \"$module\")\n";
	}
	close ($sf);
    }

    $outfile = quotify($outfile);
    $logging = ':logfile ' . quotify($logfile)  if $logfile;
    $tracing = ':markup-trace :on'  if $debug{markup};
    $trace_level = ":trace-level $debug{trace_level}"  if $debug{trace_level};
    $searchpath = quotify(join($path_sep, ".", $modules_dir, "$modules_dir/base"));

    my $exp = <<_EOT_
(progn
  (searchpath $searchpath)
  (xindy:startup
    :idxstyle $style_file
    :rawindex $raw_index
    :output $outfile
    $logging
    $tracing
    $trace_level)
  (exit))
_EOT_
  ;

    return $exp;
}


# Actual xindy call. Returns exit code.

sub call_xindy ( $$ ) {
    my ($mem_file, $xindy_exp) = @_;

    my @command = ($clisp, '-M', $mem_file, '-E', 'iso-8859-1');
    if ( $interactive ) {
	print "Proposed xindy expression:\n\n$xindy_exp\n"  unless $quiet;
    } elsif ($is_w32) {
	my ($output, $outfile) = tempfile();
	push (@temp_files, $outfile);
	$outfile=quotify($outfile);
	print $output $xindy_exp;
	close ($output);
	print "xindy startup file: $outfile\n" if $debug{script};
	push (@command, "$outfile");
    } else {
	push (@command, '-x', $xindy_exp);
    }

    if ( $debug{script} ) {
	print "modules directory: $modules_dir.\n";
	print "command: @command\n";
    }

    if ( $quiet && ! $interactive ) {
	open (STDOUT, '>', File::Spec->devnull);
    }
    system @command;
    if ( $? == -1 ) {
	print STDERR "$cmd: Could not execute xindy kernel: $!\n";
    } elsif ( $? & 127 ) {
	return 4;
    } else {
	return $? >> 8;
    }
}

sub output_version ( ;$ ) {		# optional arg: internal-version flag
    my $internal = shift;
    output_xindy_release()  unless $internal;
    print "$cmd script version: $VERSION\n";
    my $exit_code = call_xindy($mem_file, '(xindy:startup :show-version t)');
    exit ($exit_code);
}


sub output_xindy_release () {
    my $version = 'unknown';
    my $version_file;
    if ( -f "$modules_dir/../VERSION" ) {
	$version_file = "$modules_dir/../VERSION";
    } elsif ( -f "$cmd_dir/../VERSION" ) {
	$version_file = "$cmd_dir/../VERSION";
    } elsif ( -f "$lib_dir/VERSION" ) {
	$version_file = "$lib_dir/VERSION";
    }
    if ( $version_file ) {
	if ( open(VERSION, "<$version_file") ) {
	    while ( $version = <VERSION> ) {
		chomp ($version);
		$version =~ s/\#.*// ;
		$version =~ s/^\s+// ;
		$version =~ s/\s+$// ;
		last  if $version;
	    }
	    close (VERSION);
	}
    }
    print "xindy release: $version\n";
}


# Helper function: Make a proper quoted Lisp string.

sub quotify ( $ ) {
    my $s = shift;
    $s =~ s:([\\\"]):\\$1:g ;
    return "\"$s\"";
}



#======================================================================
#
# $Log: xindy.pl,v $
# Revision 1.18  2011/01/18 22:18:29  jschrod
#     Document the range raw markup incompatibility with MakeIndex.
# (Bug ticket 998541)
#
# Revision 1.17  2010/08/12 00:16:01  jschrod
#     Output help message on stdout if there's no error.
#
# Revision 1.16  2010/05/10 23:39:24  jschrod
#     Incorporate TeX-Live patches from Vladimir Volovich and Peter
# Breitenlohner: Support for TL installation scheme, support for Mac OS
# X, support for Windows in TL.
#
# Revision 1.15  2010/04/20 00:15:23  jschrod
#     Emphasize incompatibility with hyperref in man page.
#
# Revision 1.14  2009/12/03 00:28:22  jschrod
#     Search perl via env.
#
# Revision 1.13  2009/03/29 11:14:04  jschrod
#     xindy.run does not exist any more, call clisp directly.
#
# Revision 1.12  2009/03/26 17:27:28  jschrod
#  Checking for variant name din needs to take trailing hyphen into account.
#
# Revision 1.11  2009/03/22 11:08:18  jschrod
#     man page: --v is --verbose, not --version.
#
# Revision 1.10  2009/03/21 18:05:11  jschrod
#     Variant rename of din to din5007 made explicit. (Proposed by
# Zdenek Wagner at 16 Mar 09.)
#
# Revision 1.9  2008/02/17 14:55:32  jschrod
#     Use exitcode 0 when usage is explicitly demanded with --help et.al.
#
# Revision 1.8  2006/07/30 10:30:42  jschrod
#     Check if an exec() error happened and output an error message.
# (Ticket 1230801)
#
# Revision 1.7  2006/07/19 00:29:56  jschrod
#     Support for omega input markup.
#
# Revision 1.6  2005/05/02 19:16:26  jschrod
#     Support new RTE 2.2, built with CLISP 2.33.2, that needs -E option
# to specify the default charset.
#     xindy also has proper version output in Lisp now, no need for
# workarounds in script any more.
#
# Revision 1.5  2004/11/01 22:48:51  jschrod
#     Locate xindy script.
#     Terminate on option error.
#     Fix up version output.
#
# Revision 1.4  2004/08/05 14:10:54  jschrod
#     Language variant names may have hyphens now. Language names must
# not have hyphens -- the first hyphen of the -L option argument
# separates language and variant name.
#     Revision 1.3 was completely off -- I committed a copy of texindy.
# I really don't know what happened there.
#
# Revision 1.2  2004/05/26 21:30:11  jschrod
#     Added POD documentation.
#
# Revision 1.1  2004/05/24 19:47:13  jschrod
#     Introduce new driver script, as part of the "Companion Release".
#
