| .. 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 | |
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| - - ``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. |