#!/usr/bin/perl -w
#
# $Id: configpp,v 1.1 2002/10/08 18:46:02 mdb Exp $
#
# Preprocesses a configuration file (a .dop file, for instance), executing
# any include directives located in the file.

use File::Basename;

my %files = ();
my $file = shift or die "Usage: $0 file\n";

# change into the directory occupied by the file
chdir(dirname($file));
$file = basename($file);

# process this file
read_file($file, "");

sub read_file {
    my ($path, $parent) = @_;

    # do circular reference checking
    if (defined $files{$path}) {
        die "Detected circular inclusion [file=$parent, incl=$path].\n";
    }
    $files{$path} = 1;

    # read the file
    my $FILE;
    open($FILE, "$path") or die "Can't read include file '$path': $!\n";
    while (<$FILE>) {
        if (m/^.include \"([^\"]*)\"/) {
            # process the inclusion
            read_file($1, $path);
        } else {
            print $_;
        }
    }
    close($FILE);
    undef $files{$path};
}