.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later .. c:namespace:: DTV.dmx

.. _dmx_fwrite:

======================== Digital TV demux write()

Name

Digital TV demux write()

Synopsis

.. c:function:: ssize_t write(int fd, const void *buf, size_t count)

Arguments

fd File descriptor returned by a previous call to :c:func:open().

buf Buffer with data to be written

count Number of bytes at the buffer

Description

This system call is only provided by the logical device /dev/dvb/adapter?/dvr?, associated with the physical demux device that provides the actual DVR functionality. It is used for replay of a digitally recorded Transport Stream. Matching filters have to be defined in the corresponding physical demux device, /dev/dvb/adapter?/demux?. The amount of data to be transferred is implied by count.

Return Value

On success 0 is returned.

On error -1 is returned, and the errno variable is set appropriately.

.. tabularcolumns:: |p{2.5cm}|p{15.0cm}|

.. flat-table:: :header-rows: 0 :stub-columns: 0 :widths: 1 16

-  -  ``EWOULDBLOCK``
   -  No data was written. This might happen if ``O_NONBLOCK`` was
  specified and there is no more buffer space available (if
  ``O_NONBLOCK`` is not specified the function will block until buffer
  space is available).

-  -  ``EBUSY``
   -  This error code indicates that there are conflicting requests. The
  corresponding demux device is setup to receive data from the
  front- end. Make sure that these filters are stopped and that the
  filters with input set to ``DMX_IN_DVR`` are started.

The generic error codes are described at the :ref:Generic Error Codes <gen-errors> chapter.