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><TD ALIGN="LEFT" VALIGN="BASELINE" WIDTH="100%" CLASS="name"
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><B
>read-byte</B
></TD
><TD ALIGN="RIGHT" VALIGN="BASELINE" WIDTH="0" NOWRAP="NOWRAP" CLASS="ftype"
><I
>Function</I
></TD
></TR
></TABLE
><HR
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><UL CLASS="subtoc"
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><DL
><DT
><B
>Syntax</B
></DT
><DD
><P CLASS="j"
><B
>read-byte</B
> <SPAN CLASS="cmssi"
>stream</SPAN
> <SPAN CLASS="cmtt"
>&amp;optional</SPAN
> <SPAN CLASS="cmssi"
>eof-error-p</SPAN
> <SPAN CLASS="cmssi"
>eof-value</SPAN
> <SPAN CLASS="arrow"
>&#8594;</SPAN
> <SPAN CLASS="cmssi"
>byte</SPAN
></P
></DD
><DT
><B
>Arguments and Values</B
></DT
><DD
><P CLASS="j"
><VAR CLASS="param"
>stream</VAR
> &#8212; a <A HREF="26_1_Glossary.html#binary"
><EM CLASS="term"
>binary</EM
></A
> <A HREF="26_1_Glossary.html#input"
><EM CLASS="term"
>input</EM
></A
> <A HREF="26_1_Glossary.html#stream"
><EM CLASS="term"
>stream</EM
></A
>. </P
><P CLASS="j"
><VAR CLASS="param"
>eof-error-p</VAR
> &#8212; a <A HREF="26_1_Glossary.html#generalized_boolean"
><EM CLASS="term"
>generalized boolean</EM
></A
>. The default is <A HREF="26_1_Glossary.html#true"
><EM CLASS="term"
>true</EM
></A
>. </P
><P CLASS="j"
><VAR CLASS="param"
>eof-value</VAR
> &#8212; an <A HREF="26_1_Glossary.html#object"
><EM CLASS="term"
>object</EM
></A
>. The default is <SPAN CLASS="misc"
><B
>nil</B
></SPAN
>. </P
><P CLASS="j"
><VAR CLASS="param"
>byte</VAR
> &#8212; an <A HREF="26_1_Glossary.html#integer"
><EM CLASS="term"
>integer</EM
></A
>, or the <VAR CLASS="param"
>eof-value</VAR
>.</P
></DD
><DT
><B
>Description</B
></DT
><DD
><P CLASS="j"
><A HREF="f_read-byte.html" CLASS="funref"
><B
>read-byte</B
></A
> reads and returns one byte from <VAR CLASS="param"
>stream</VAR
>. </P
><P CLASS="j"
>If an <A HREF="26_1_Glossary.html#end_of_file"
><EM CLASS="term"
>end of file</EM
></A
><SPAN CLASS="meaning"
><SUB CLASS="sub"
><SPAN CLASS="cmr"
>2</SPAN
></SUB
></SPAN
> occurs and <VAR CLASS="param"
>eof-error-p</VAR
> is <A HREF="26_1_Glossary.html#false"
><EM CLASS="term"
>false</EM
></A
>, the <VAR CLASS="param"
>eof-value</VAR
> is returned.</P
></DD
><DT
><B
>Examples</B
></DT
><DD
><PRE CLASS="screen"
> (with-open-file (s "temp-bytes"
:direction :output
:element-type 'unsigned-byte)
(write-byte 101 s)) <SPAN CLASS="cmsy"
><SPAN CLASS="arrow"
>&#8594;</SPAN
></SPAN
> 101
(with-open-file (s "temp-bytes" :element-type 'unsigned-byte)
(format t "~S ~S" (read-byte s) (read-byte s nil 'eof)))
<SPAN CLASS="cmr"
>&#8883;</SPAN
> 101 EOF
<SPAN CLASS="cmsy"
><SPAN CLASS="arrow"
>&#8594;</SPAN
></SPAN
> NIL</PRE
></DD
><DT
><B
>Side Effects</B
></DT
><DD
><P CLASS="j"
>Modifies <VAR CLASS="param"
>stream</VAR
>.</P
></DD
><DT
><B
>Exceptional Situations</B
></DT
><DD
><P CLASS="j"
>Should signal an error of <A HREF="26_1_Glossary.html#type"
><EM CLASS="term"
>type</EM
></A
> <A HREF="t_type-error.html" CLASS="typeref"
><B
>type-error</B
></A
> if <VAR CLASS="param"
>stream</VAR
> is not a <A HREF="26_1_Glossary.html#stream"
><EM CLASS="term"
>stream</EM
></A
>. </P
><P CLASS="j"
>Should signal an error of <A HREF="26_1_Glossary.html#type"
><EM CLASS="term"
>type</EM
></A
> <A HREF="t_error.html" CLASS="typeref"
><B
>error</B
></A
> if <VAR CLASS="param"
>stream</VAR
> is not a <A HREF="26_1_Glossary.html#binary"
><EM CLASS="term"
>binary</EM
></A
> <A HREF="26_1_Glossary.html#input"
><EM CLASS="term"
>input</EM
></A
> <A HREF="26_1_Glossary.html#stream"
><EM CLASS="term"
>stream</EM
></A
>. </P
><P CLASS="j"
>If there are no <A HREF="26_1_Glossary.html#byte"
><EM CLASS="term"
>bytes</EM
></A
> remaining in the <VAR CLASS="param"
>stream</VAR
> and <VAR CLASS="param"
>eof-error-p</VAR
> is <A HREF="26_1_Glossary.html#true"
><EM CLASS="term"
>true</EM
></A
>, an error of <A HREF="26_1_Glossary.html#type"
><EM CLASS="term"
>type</EM
></A
> <A HREF="t_end-of-file.html" CLASS="typeref"
><B
>end-of-file</B
></A
> is signaled.</P
></DD
><DT
><B
>See Also</B
></DT
><DD
><P CLASS="j"
><A HREF="f_read-char.html" CLASS="funref"
><B
>read-char</B
></A
>, <A HREF="f_read-sequence.html" CLASS="funref"
><B
>read-sequence</B
></A
>, <A HREF="f_write-byte.html" CLASS="funref"
><B
>write-byte</B
></A
></P
></DD
></DL
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