This system call opens a named audio device (e.g.
/dev/dvb/adapter0/audio0) 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
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 Audio Device
in O_RDWR mode. All other attempts to open the device in this mode will
fail, and an error code will be returned. If the Audio Device is opened
in O_RDONLY mode, the only ioctl call that can be used is
AUDIO_GET_STATUS. All other call will return with an error code.