Function read-byte

Syntax:

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, Removed by KMP because in the presence of stream element type upgrading, this won't necessarily work as expected if the file was written with an incompatible element type. of the \term{stream element type} of \term{stream} or the eof-value.

Description:

22.2.2 3read-byte reads and returns one byte from stream.

If an end of file₂ occurs and eof-error-p is false, the eof-value is returned.

Examples:

 (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.