Is there an Arduino functional equivalent to Processing's selectOutput?
Thank you

Come on - not willing to be harsh - but that’s a dumb question...

Opens a platform-specific file chooser dialog to select a file for output. After the selection is made, the selected File will be passed to the 'callback' function. If the dialog is closed or canceled, null will be sent to the function, so that the program is not waiting for additional input. The callback is necessary because of how threading works.

Do you have a standard embeded file system?
do you have a standard embeded screen?
do you have a standard embeded user interface to select something?

If you add those elements to your arduino, you sure can code something specific to your setup...