NAME

       comedi_get_buffer_write_offset - streaming buffer write offset

SYNOPSIS

       #include <comedilib.h>

       int comedi_get_buffer_write_offset(comedi_t * device, unsigned int subdevice);

DESCRIPTION

       The function comedi_get_buffer_write_offset is used on a subdevice that has a Comedi
       command in progress to get the current write 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.

RETURN VALUE

       On success, comedi_get_buffer_write_offset returns the current write position as an offset
       in bytes from the start of the buffer. On failure, -1 is returned.

AUTHORS

       David Schleef <ds@schleef.org>
           Author.

       Frank Mori Hess <fmhess@users.sourceforge.net>
           Author.

       Herman Bruyninckx <Herman.Bruyninckx@mech.kuleuven.ac.be>
           Author.

       Bernd Porr <tech@linux-usb-daq.co.uk>
           Author.

       Ian Abbott <abbotti@mev.co.uk>
           Author.

       Éric Piel <piel@delmic.com>
           Author.

COPYRIGHT

       Copyright © 1998-2003 David Schleef
       Copyright © 2001-2003, 2005, 2008 Frank Mori Hess
       Copyright © 2002-2003 Herman Bruyninckx
       Copyright © 2012 Bernd Porr
       Copyright © 2012 Ian Abbott
       Copyright © 2012, 2015 Éric Piel

       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.

       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.

       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.

       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.