ACprogramcancallonalargenumberoffunctionsfromtheDinkumC99Library,aconformingimplementationoftheStandardClibrary,asrevisedin1999.Thesefunctionsperformessentialservicessuchasinputandoutput.Theyalsoprovideefficientimplementationsoffrequentlyusedoperations.Numerousmacroandtypedefinition