The current position in the buffer. This is the index of the next
character to be read from the buf array.
This value is always in the range 0
through count. If it is less
than count, then buf[pos]
is the next byte to be supplied as input;
if it is equal to count, then
the next read or skip
operation will require more bytes to be
read from the contained input stream.
java.io.BufferedInputStream.buf
Diagram: InputStream