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+.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
+.. c:namespace:: DTV.dmx
+
+.. _dmx_fread:
+
+=======================
+Digital TV demux read()
+=======================
+
+Name
+----
+
+Digital TV demux read()
+
+Synopsis
+--------
+
+.. c:function:: size_t read(int fd, void *buf, size_t count)
+
+Arguments
+---------
+
+``fd``
+  File descriptor returned by a previous call to :c:func:`open()`.
+
+ ``buf``
+   Buffer to be filled
+
+``count``
+   Max number of bytes to read
+
+Description
+-----------
+
+This system call returns filtered data, which might be section or Packetized
+Elementary Stream (PES) data. The filtered data is transferred from
+the driver's internal circular buffer to ``buf``. The maximum amount of data
+to be transferred is implied by count.
+
+.. note::
+
+   if a section filter created with
+   :c:type:`DMX_CHECK_CRC <dmx_sct_filter_params>` flag set,
+   data that fails on CRC check will be silently ignored.
+
+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 to return and ``O_NONBLOCK`` was specified.
+
+    -  -  ``EOVERFLOW``
+       -  The filtered data was not read from the buffer in due time,
+	  resulting in non-read data being lost. The buffer is flushed.
+
+    -  -  ``ETIMEDOUT``
+       -  The section was not loaded within the stated timeout period.
+          See ioctl :ref:`DMX_SET_FILTER` for how to set a timeout.
+
+    -  -  ``EFAULT``
+       -  The driver failed to write to the callers buffer due to an
+          invalid \*buf pointer.
+
+The generic error codes are described at the
+:ref:`Generic Error Codes <gen-errors>` chapter.