A stream is an object that can be used with an input or output function to identify an appropriate source or sink of characters or bytes for that operation. A character stream is a source or sink of characters. A binary stream is a source or sink of bytes.
Some operations may be performed on any kind of stream; the next figure provides a list of standardized operations that are potentially useful with any kind of stream.
close stream-element-type input-stream-p streamp interactive-stream-p with-open-stream output-stream-p
Figure 21-1. Some General-Purpose Stream Operations
Other operations are only meaningful on certain stream types. For example, read-char is only defined for character streams and read-byte is only defined for binary streams.
220.127.116.11 Abstract Classifications of Streams
18.104.22.168 Abstract Classifications of Streams
22.214.171.124 Other Subclasses of Stream