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<TITLE>int v24Read</TITLE>
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<H2>int <A HREF="#DOC.DOCU">v24Read</A></H2><H2>( v24_port_t* port, unsigned char* Buffer,<BR> size_t Len )</H2>
<A NAME="DOC.DOCU"></A>
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<H2>Documentation</H2>
<BLOCKQUOTE><TT>v24Read</TT> is the basic function to get one or more received data bytes out
of the receive queue. If the queue is empty, the behavious of the function
depends on the used <EM>open flags</EM>. Without any open flags, a empty
receive queue leads to an error. If the flag <TT>V24_NON_BLOCK</TT> is used, the
function will wait for the reception of character. The wait time is limited
to the given <EM>timeout time</EM>. If this limit is exceeded, the function
aborts waiting. If nothing is read, the returned value is <TT>0</TT>, and the error
code is set to <TT>V24_E_TIMEOUT</TT>. At this level it's no real error, so there
is no error report for the debug output (see <TT>V24_DEBUG_ON</TT> in
<!1><A HREF="v24OpenPort.html">v24OpenPort</A>).
<P>The parameter <TT>Buffer</TT> references a buffer that should hold the received
characters. The parameter <TT>Len</TT> is the number of characters to read.
<P>The function returns the number of character read. An error is indicated by
a return vlaue of <TT>-1</TT>. Use <!1><A HREF="v24QueryErrno.html">v24QueryErrno</A> to get the exact error code.
<P>Possible error code are <TT>V24_OK</TT>, <TT>V24_E_NULL_POINTER</TT>, <TT>V24_E_ILLHANDLE</TT>,
<TT>V24_E_TIMEOUT</TT> or <TT>V24_READ</TT>.
<P><B>Note:</B> the caller has to ensure, that <TT>Buffer</TT> can hold the <TT>Len</TT>
characters.
<P></BLOCKQUOTE>
<DL><DT><DT><B>Parameters:</B><DD><B>port</B> - pointer to handle of the opened port.
<BR><B>Buffer</B> - pointer to buffer to hold the data.
<BR><B>Len</B> - number of characters to receive.
<BR><DT><B>Returns:</B><DD> (int) number of received characters or <TT>-1</TT>.
<BR><DT><B>See Also:</B><DD><!1><A HREF="v24QueryErrno.html">v24QueryErrno</A>, <!1><A HREF="v24Getc.html">v24Getc</A>, v24Gets.
<BR><DD></DL><P><P><I><A HREF="index.html">Alphabetic index</A></I></P><HR>
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