<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN""http://www.w3.org/TR/html4/loose.dtd"> <HTML ><HEAD ><TITLE >comedi_get_buffer_offset</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK REL="HOME" TITLE=" Comedi " HREF="index.html"><LINK REL="UP" TITLE=" Comedi Function Reference " HREF="x4629.html#FUNCTIONREFERENCE"><LINK REL="PREVIOUS" TITLE="comedi_mark_buffer_written" HREF="r6300.html"><LINK REL="NEXT" TITLE="comedi_get_timer" HREF="r6344.html"></HEAD ><BODY CLASS="REFENTRY" BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#0000FF" VLINK="#840084" ALINK="#0000FF" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >Comedi: The <SPAN CLASS="emphasis" ><I CLASS="EMPHASIS" >Control and Measurement Device Interface</I ></SPAN > handbook </TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="r6300.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="r6344.html" ACCESSKEY="N" >Next</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="FUNC-REF-COMEDI-GET-BUFFER-OFFSET" ></A >comedi_get_buffer_offset</H1 ><DIV CLASS="REFNAMEDIV" ><A NAME="AEN6327" ></A ><H2 >Name</H2 >comedi_get_buffer_offset -- streaming buffer status</DIV ><DIV CLASS="REFSYNOPSISDIV" ><A NAME="AEN6330" ></A ><H2 >Synopsis</H2 ><DIV CLASS="FUNCSYNOPSIS" ><P ></P ><A NAME="AEN6331" ></A ><PRE CLASS="FUNCSYNOPSISINFO" >#include <comedilib.h></PRE ><P ><CODE ><CODE CLASS="FUNCDEF" >int comedi_get_buffer_offset</CODE >(comedi_t * device, unsigned int subdevice);</CODE ></P ><P ></P ></DIV ></DIV ><DIV CLASS="REFSECT1" ><A NAME="AEN6340" ></A ><H2 > Description </H2 ><P >The function comedi_get_buffer_offset() is used on a subdevice that has a Comedi command in progress. This function returns the offset in bytes of the read pointer in the streaming buffer. This offset is only useful for memory mapped buffers. If there is an error, -1 is returned.</P ><P > </P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="r6300.html" ACCESSKEY="P" >Prev</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Home</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="r6344.html" ACCESSKEY="N" >Next</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >comedi_mark_buffer_written</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="x4629.html#FUNCTIONREFERENCE" ACCESSKEY="U" >Up</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >comedi_get_timer</TD ></TR ></TABLE ></DIV ></BODY ></HTML >