the word dude can mean anything in the english language, depending upon accompanying gestures, the intonation and situation.
dude!! (hey man, its good to see you!)
dude. (hey. that thing you just did? not cool.)
dude! (awesome! i got a great new job!)
Dude? (will you hand me the remote please?)
DUDE!! (you slept with my girlfriend, and im upset)
dude.. (expressing; excitement, sadness, anger, fear, sexual arousal, discomfort, and or the lack of anything to say)