#!/usr/bin/perl -w
#
# POD currently doesn't support any sort of =include directive.  This
# processor works around that limitation.  It takes a list of files ending in
# *.in as its argument and processes any POD directives of the form =include
# <file> in that file, generating a file with the *.in suffix removed.  All
# paths are taken to be relative to the directory containing the file being
# processed.
#
# Currently, only single include nesting is supported.  The included file is
# not processed for additional =include statements.

require 5.006;

use Cwd qw(getcwd);
use File::Basename qw(dirname basename);

my $start = getcwd;
for my $file (@ARGV) {
    chdir $start or die "cannot chdir to $start: $!\n";
    my $dir = dirname ($file);
    my $out = $file;
    unless ($out =~ s/\.in\z//) {
        die "input file $file does not end in .in\n";
    }
    open (FILE, '<', $file) or die "cannot open $file: $!\n";
    open (OUT, '>', $out) or die "cannot open $out: $!\n";
    chdir $dir or die "cannot chdir to $dir: $!\n";
    local $/ = '';
    local $_;
    while (<FILE>) {
        if (/^=include\s+(\S+)/) {
            open (INCLUDE, '<', $1) or die "cannot open $1: $!\n";
            local $/;
            print OUT <INCLUDE> or die "cannot read/write from $1: $!\n";
            close INCLUDE or die "cannot read from $1: $!\n";
            print OUT "\n" or die "cannot write to $out: $!\n";
        } else {
            print OUT $_ or die "cannot write to $out: $!\n";
        }
    }
    close OUT or die "cannot write to $out: $!\n";
    close FILE or die "cannot read from $file\n";
}