send current line to external command in vim (without capture)

Question

The goal is to use the current line as a TODO and send this to some external program. Something like this:

:! /usr/bin/todo "content of current line" 

I know of the filtering command but this implies that I want to edit the current buffer which I do not want (:.! acts as a filter). I know how to get the current file with '%' but isn't there any way to get some other content ? Maybe by using :execute ...

Answer 1

:.! works as a filter, but :.w ! (mind the space!) just passes the output. See :help :w_c. I.e.

:.w !/usr/bin/todo -