Command line data

Can command-line data such as curve length, area, volume be copied or exported?

CommandHistory and window opens with command history. Select Copy all or Save as.
or
-CommandHistory (leading hyphen) to start command with command line options
or
Highlight the desired text using the cursor, then right click for Save, etc options…
or
Highlight the desired text using the cursor, Ctrl-C to copy, and then Ctrl-V to paste where desired.

https://docs.mcneel.com/rhino/7/help/en-us/index.htm#commands/commandhistory.htm

There is also the possibility via some simple scripts to export object data as a text or .csv file.

PetersTools will export or copy to clipboard the area, volume, and bounding box size (but not length) of objects.