How to copy and paste lines in Nano on OSX
Solution 1:
The problem is that in Mac Terminal, the alt key doesn't work unless you change the Terminal Preferences to enable Use Option as Meta key. Then alt+6 will work properly to copy.
Another choice is to use the ESC key instead of alt. So do ESC+6.
Solution 2:
You may be able to cut multiple lines into a buffer using Ctrl-K, and paste them back in using Ctrl-U.
Note that this does not copy the text onto your OS X clipboard, but uses a buffer inside of nano (or the shell?) to perform the actions.