sub runDir($$);
sub runDir($$) {
    my $prefix = shift @_;
    # print $prefix,"\n";
    my $dir = shift @_;
    #print "******$dir***","\n";
    opendir(DIR, $dir) or die $!;
    my @entries = readdir(DIR);
    # print @entries,"\n";
    close(DIR);
    foreach my $file (@entries) {
        next if ($file =~ /^\.+$/);
        if ( -d $dir . '/' . $file) {
            runDir($prefix . $file . '_', $dir . '/' . $file);
        } elsif ( ( -f $dir . '/' . $file ) && ( $file =~ /\.config$/ ) && ($file !~ /^$prefix/)) {
            my $suffix = $file;
            $suffix =~ s/^(\S+)-.+\.config$/$1.config/;
            
            rename $dir . '/' . $file, $dir . '/' . $prefix . $suffix ;
        }
    }
}
runDir('',$output_dir);