[z991]

Wow that is also very cool. For those wondering, this is what it looks like:

  $ sudo apt install slop
  $ slop
       <selects an area on screen>
  1719x1403+1080+277

[machinestops]

Putting the two together is easy too:

$ clipscreen $(slop -F "%x %y %w %h")

NB. The lack of quotes around $() enables wordsplitting to occur.

[Narishma]

I think you got the size and position switched.

[samwhiteUK]

Or

$ clipscreen $(slop | tr -s "+x" " ")