Network exploration tool and security / port scanner

--top-ports <integer of 1 or greater>
    Scans the N highest-ratio ports found in nmap-services file.

-oN filespec (normal output) .
    Requests that normal output be directed to the given filename. As discussed above, this differs
    slightly from interactive output.

Commands separated  by  a ; are executed sequentially; the shell waits for each command to terminate in turn.  The
return status is the exit status of the last command executed.

COMMENTS
      In a non-interactive shell, or an interactive shell in which the interactive_comments option to the shopt
      builtin is enabled (see SHELL BUILTIN COMMANDS below), a word beginning with # causes that word  and  all
      remaining  characters  on that line to be ignored.  An interactive shell without the interactive_comments
      option enabled does not allow comments.  The interactive_comments option is on by default in  interactive
      shells.