+The scanner must deal with the case of parsing a whole command string,
+eg. for a command that the user types in:
+
+ ><fs> add-drive-opts "/tmp/foo" readonly:true
+
+and also with parsing single words from the command line:
+
+ guestfish add-drive-opts /tmp/foo readonly:true
+
+Note the quotes are for scanning and don't indicate types.
+
+We should also allow variables and expressions as part of this new
+parsing code, eg:
+
+ set roots inspect-os
+ set product inspect-get-product-name %{roots[0]}
+
+% is better than $ because of shell escaping and confusion with shell
+variables.
+
+Can we combine this with ability to set and read environment
+variables? Currently guestfish uses many environment variables like
+$EDITOR without any corresponding ability to set them.
+
+ set EDITOR /usr/bin/emacs
+ echo $EDITOR # or %{EDITOR}
+ edit /etc/resolv.conf
+
+live CD inspection