e followed by one of the following:
KB 1000, K 1024, MB 1000*1000, M 1024*1024, and so on for G,T,P,E,Z,Y,R,Q.
Binary prefixes can be used, too: KiB=K, MiB=M, and so on.
In this case the corresponding stream will be fully buffered with the buffer
size set to MODE bytes.