Common greeting in Cornwall is “Alright” short for “All Rite Are EEE” pronounced “aweriteareee”
Usual answer is “Alright” or “Yes - You?” saves a lot of breath and can be done across the street
If someone actually replies by telling you how they are, they are likely to be Visitors. 
Alternatively, “You Boy - Woz On?” to which a more descriptive answer is optional 