finished or conserve file resources. The function fflush ( expr ) flushes the output file or pipe ... associated with expr . Fflush returns 0 if expr is an open output stream elsesubsection Special File Names , below.) fflush( [ file ] ) Flush any buffers associated with the open outputsubsection Special File Names , below.) fflush( [ file ] ) Flush any buffers associated with the open outputsubsection Special File Names , below.) fflush( [ file ] ) Flush any buffers associated with the open output