sub Traverse {
    my $dir = shift;
    opendir my $dh, $dir or return 0;
    for my $file ( grep !/^\.\.?$/, readdir $dh ) {
        my $path = "$dir/$file";
        if ( -d $path ) {
            Traverse( $path, @_ );
        }
        elsif ( -f $path )  {
            ProcessFile( $path, @_ );
        }
        else {
            warn "$path not -d or -f\n";
        }
    }
    closedir $dh;
}
##</code><code>##

sub ProcessFile {
    my ( $path, $windows ) = @_;
    my $pid = 0;
    if ( $windows ) {
        open \*FH, "<$path" or die "$!: $path";
    }
    else {
        $pid = open \*FH, "dos2unix $path |"
          or die "$!: dos2unix $path |";
    }
    my $fh = \*FH;
    # file content (<$fh>) is now unix/dos transparent
    close $fh;
    $pid and waitpid $pid,0;
}