'\" t
.\"     Title: comedi_get_buffer_read_offset
.\"    Author: David Schleef <ds@schleef.org>
.\" Generator: DocBook XSL Stylesheets v1.79.1 <http://docbook.sf.net/>
.\"      Date: 12/30/2018
.\"    Manual: Comedi reference
.\"    Source: Comedi
.\"  Language: English
.\"
.TH "COMEDI_GET_BUFFER_RE" "3" "12/30/2018" "Comedi" "Comedi reference"
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.SH "NAME"
comedi_get_buffer_read_offset \- streaming buffer read offset
.SH "SYNOPSIS"
.sp
.ft B
.nf
#include <comedilib\&.h>
.fi
.ft
.HP \w'int\ comedi_get_buffer_read_offset('u
.BI "int comedi_get_buffer_read_offset(comedi_t\ *\ " "device" ", unsigned\ int\ " "subdevice" ");"
.SH "DESCRIPTION"
.PP
The function
\fBcomedi_get_buffer_read_offset\fR
is used on a subdevice that has a Comedi command in progress to get the current read position in the streaming buffer as an offset in bytes from the start of the buffer\&. The position will wrap around to 0 when it reaches the buffer size\&. This offset is only useful for memory mapped buffers\&.
.PP
This function replaces
\fBcomedi_get_buffer_offset\fR
and has the same functionality\&.
.SH "RETURN VALUE"
.PP
On success,
\fBcomedi_get_buffer_read_offset\fR
returns the current read position as an offset in bytes from the start of the buffer\&. On failure,
\-1
is returned\&.
.PP
.SH "AUTHORS"
.PP
\fBDavid Schleef\fR <\&ds@schleef.org\&>
.RS 4
Author.
.RE
.PP
\fBFrank Mori Hess\fR <\&fmhess@users.sourceforge.net\&>
.RS 4
Author.
.RE
.PP
\fBHerman Bruyninckx\fR <\&Herman.Bruyninckx@mech.kuleuven.ac.be\&>
.RS 4
Author.
.RE
.PP
\fBBernd Porr\fR <\&tech@linux-usb-daq.co.uk\&>
.RS 4
Author.
.RE
.PP
\fBIan Abbott\fR <\&abbotti@mev.co.uk\&>
.RS 4
Author.
.RE
.PP
\fB\('Eric Piel\fR <\&piel@delmic.com\&>
.RS 4
Author.
.RE
.SH "COPYRIGHT"
.br
Copyright \(co 1998-2003 David Schleef
.br
Copyright \(co 2001-2003, 2005, 2008 Frank Mori Hess
.br
Copyright \(co 2002-2003 Herman Bruyninckx
.br
Copyright \(co 2012 Bernd Porr
.br
Copyright \(co 2012 Ian Abbott
.br
Copyright \(co 2012, 2015 \('Eric Piel
.br
.PP
This document is part of Comedilib. In the context of this document, the term "source code" as defined by the license is interpreted as the XML source.
.PP
This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation, version 2.1 of the License.
.PP
This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
.PP
You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
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