# loop through file names looking for one we can lock
        open ( my $file_handle, '+<', $file_name ) or next;
        if ( !flock( $file_handle, LOCK_EX | LOCK_NB ) ) {
            close( $file_handle );
            next;
        }
        # do some work here based on the file contents
        unlink $file_name;
        close( $file_handle );