1059b1c5bSMauro Carvalho Chehab.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later 2f9b2e8aaSMauro Carvalho Chehab.. c:namespace:: DTV.dmx 354f38fcaSMauro Carvalho Chehab 454f38fcaSMauro Carvalho Chehab.. _dmx_fread: 554f38fcaSMauro Carvalho Chehab 654f38fcaSMauro Carvalho Chehab======================= 754f38fcaSMauro Carvalho ChehabDigital TV demux read() 854f38fcaSMauro Carvalho Chehab======================= 954f38fcaSMauro Carvalho Chehab 1054f38fcaSMauro Carvalho ChehabName 1154f38fcaSMauro Carvalho Chehab---- 1254f38fcaSMauro Carvalho Chehab 1354f38fcaSMauro Carvalho ChehabDigital TV demux read() 1454f38fcaSMauro Carvalho Chehab 1554f38fcaSMauro Carvalho ChehabSynopsis 1654f38fcaSMauro Carvalho Chehab-------- 1754f38fcaSMauro Carvalho Chehab 1854f38fcaSMauro Carvalho Chehab.. c:function:: size_t read(int fd, void *buf, size_t count) 1954f38fcaSMauro Carvalho Chehab 2054f38fcaSMauro Carvalho ChehabArguments 2154f38fcaSMauro Carvalho Chehab--------- 2254f38fcaSMauro Carvalho Chehab 2354f38fcaSMauro Carvalho Chehab``fd`` 24f9b2e8aaSMauro Carvalho Chehab File descriptor returned by a previous call to :c:func:`open()`. 2554f38fcaSMauro Carvalho Chehab 2654f38fcaSMauro Carvalho Chehab ``buf`` 2754f38fcaSMauro Carvalho Chehab Buffer to be filled 2854f38fcaSMauro Carvalho Chehab 2954f38fcaSMauro Carvalho Chehab``count`` 3054f38fcaSMauro Carvalho Chehab Max number of bytes to read 3154f38fcaSMauro Carvalho Chehab 3254f38fcaSMauro Carvalho ChehabDescription 3354f38fcaSMauro Carvalho Chehab----------- 3454f38fcaSMauro Carvalho Chehab 3554f38fcaSMauro Carvalho ChehabThis system call returns filtered data, which might be section or Packetized 3654f38fcaSMauro Carvalho ChehabElementary Stream (PES) data. The filtered data is transferred from 37*c11669f7SMauro Carvalho Chehabthe driver's internal circular buffer to ``buf``. The maximum amount of data 3854f38fcaSMauro Carvalho Chehabto be transferred is implied by count. 3954f38fcaSMauro Carvalho Chehab 4054f38fcaSMauro Carvalho Chehab.. note:: 4154f38fcaSMauro Carvalho Chehab 4254f38fcaSMauro Carvalho Chehab if a section filter created with 4354f38fcaSMauro Carvalho Chehab :c:type:`DMX_CHECK_CRC <dmx_sct_filter_params>` flag set, 4454f38fcaSMauro Carvalho Chehab data that fails on CRC check will be silently ignored. 4554f38fcaSMauro Carvalho Chehab 4654f38fcaSMauro Carvalho ChehabReturn Value 4754f38fcaSMauro Carvalho Chehab------------ 4854f38fcaSMauro Carvalho Chehab 4954f38fcaSMauro Carvalho ChehabOn success 0 is returned. 5054f38fcaSMauro Carvalho Chehab 5154f38fcaSMauro Carvalho ChehabOn error -1 is returned, and the ``errno`` variable is set 5254f38fcaSMauro Carvalho Chehabappropriately. 5354f38fcaSMauro Carvalho Chehab 5454f38fcaSMauro Carvalho Chehab.. tabularcolumns:: |p{2.5cm}|p{15.0cm}| 5554f38fcaSMauro Carvalho Chehab 5654f38fcaSMauro Carvalho Chehab.. flat-table:: 5754f38fcaSMauro Carvalho Chehab :header-rows: 0 5854f38fcaSMauro Carvalho Chehab :stub-columns: 0 5954f38fcaSMauro Carvalho Chehab :widths: 1 16 6054f38fcaSMauro Carvalho Chehab 6154f38fcaSMauro Carvalho Chehab - - ``EWOULDBLOCK`` 6254f38fcaSMauro Carvalho Chehab - No data to return and ``O_NONBLOCK`` was specified. 6354f38fcaSMauro Carvalho Chehab 6454f38fcaSMauro Carvalho Chehab - - ``EOVERFLOW`` 6554f38fcaSMauro Carvalho Chehab - The filtered data was not read from the buffer in due time, 6654f38fcaSMauro Carvalho Chehab resulting in non-read data being lost. The buffer is flushed. 6754f38fcaSMauro Carvalho Chehab 6854f38fcaSMauro Carvalho Chehab - - ``ETIMEDOUT`` 6954f38fcaSMauro Carvalho Chehab - The section was not loaded within the stated timeout period. 7054f38fcaSMauro Carvalho Chehab See ioctl :ref:`DMX_SET_FILTER` for how to set a timeout. 7154f38fcaSMauro Carvalho Chehab 7254f38fcaSMauro Carvalho Chehab - - ``EFAULT`` 7354f38fcaSMauro Carvalho Chehab - The driver failed to write to the callers buffer due to an 7454f38fcaSMauro Carvalho Chehab invalid \*buf pointer. 7554f38fcaSMauro Carvalho Chehab 7654f38fcaSMauro Carvalho ChehabThe generic error codes are described at the 7754f38fcaSMauro Carvalho Chehab:ref:`Generic Error Codes <gen-errors>` chapter. 78