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Function READ-BYTE


read-byte stream &optional eof-error-p eof-value => byte

Arguments and Values:

stream---a binary input stream.

eof-error-p---a generalized boolean. The default is true.

eof-value---an object. The default is nil.

byte---an integer, or the eof-value.


read-byte reads and returns one byte from stream.

If an end of file[2] occurs and eof-error-p is false, the eof-value is returned.


 (with-open-file (s "temp-bytes" 
                     :direction :output
                     :element-type 'unsigned-byte)
    (write-byte 101 s)) =>  101
 (with-open-file (s "temp-bytes" :element-type 'unsigned-byte)
    (format t "~S ~S" (read-byte s) (read-byte s nil 'eof)))
>>  101 EOF
=>  NIL

Side Effects:

Modifies stream.

Affected By: None.

Exceptional Situations:

Should signal an error of type type-error if stream is not a stream.

Should signal an error of type error if stream is not a binary input stream.

If there are no bytes remaining in the stream and eof-error-p is true, an error of type end-of-file is signaled.

See Also:

read-char, read-sequence, write-byte

Notes: None.

The following X3J13 cleanup issues, not part of the specification, apply to this section:

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