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linux-next/Documentation/media/uapi/dvb/ca-fopen.rst

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.. -*- coding: utf-8; mode: rst -*-
.. _ca_fopen:
====================
Digital TV CA open()
====================
Name
----
Digital TV CA open()
Synopsis
--------
.. c:function:: int open(const char *name, int flags)
:name: dvb-ca-open
Arguments
---------
``name``
Name of specific Digital TV CA device.
``flags``
A bit-wise OR of the following flags:
.. flat-table::
:header-rows: 0
:stub-columns: 0
-
- O_RDONLY
- read-only access
-
- O_RDWR
- read/write access
-
- O_NONBLOCK
- open in non-blocking mode
(blocking mode is the default)
Description
-----------
This system call opens a named ca device (e.g. ``/dev/dvb/adapter?/ca?``)
for subsequent use.
When an open() call has succeeded, the device will be ready for use. The
significance of blocking or non-blocking mode is described in the
documentation for functions where there is a difference. It does not
affect the semantics of the open() call itself. A device opened in
blocking mode can later be put into non-blocking mode (and vice versa)
using the F_SETFL command of the fcntl system call. This is a standard
system call, documented in the Linux manual page for fcntl. Only one
user can open the CA Device in O_RDWR mode. All other attempts to open
the device in this mode will fail, and an error code will be returned.
Return Value
------------
On success 0 is returned.
On error -1 is returned, and the ``errno`` variable is set
appropriately.
Generic error codes are described at the
:ref:`Generic Error Codes <gen-errors>` chapter.