Coming from a Visual Studio background...
How do I tell Eclipse that it should auto save when ever I build rather than ask each time.
VS.NET has it under "Options", but I can't find it in Eclipse.
I use a Mac.
First, try
Window -> Preferences -> General -> Workspace. There you can check "Save automatically before build" and "Build automatically."
If that does not work,
PLEASE TRY
Preferences -> Run/Debug -> Launching -> "Save dirty editors before launching"