I have a tendency to miss-type while trying to Ctrl-X to exit nano.
Every now and then I'll try to re-open the file and get the Nano "File xxx is being edited". How do I switch back to the open file? And also, what am I miss-typing to cause this to happen?
nano creates a lock file once you try to edit the file, I would say just try to move it and it might work.
First check if there is a process editing the file.
$> jobs
You will get a list of background jobs, look for Stopped ones.
If there is and it's your editor, try re-attaching to it:
$> fg <n>
Else, if there is no running nano, make sure there is no lock-file.
ls -A *.swp
If there is, remove it.
rm nnn.swp
If you still have trouble editing the file, reboot and restart above. Maybe there are more things to try, but that's all I can think of...