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.. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
.. c:namespace:: DTV.ca
.. _ca_fopen:
====================
Digital TV CA open()
====================
Name
----
Digital TV CA open()
Synopsis
--------
.. c:function:: int open(const char *name, int flags)
Arguments
---------
``name``
Name of specific Digital TV CA device.
``flags``
A bit-wise OR of the following flags:
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- - ``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.