snd_ctl_file_descriptor()

Get the control file descriptor

Synopsis:

#include <sys/asoundlib.h>

int snd_ctl_file_descriptor( snd_ctl_t *handle );

Arguments:

handle
The handle for the control connection to the card. This must be a handle created by snd_ctl_open() .

Library:

libasound.so

Use the -l asound option to qcc to link against this library.

Description:

The snd_ctl_file_descriptor() function returns the file descriptor of the connection to the control interface.

You can use the file descriptor for the select() function (see the QNX Library Reference) for determining if something can be read or written. Your application should then call snd_ctl_read() if data is waiting to be read.

Returns:

The file descriptor of the connection to the control interface, or a negative value if an error occurs.

Errors:

-EINVAL
Invalid handle argument.

Classification:

QNX Neutrino

Safety:
Cancellation point No
Interrupt handler No
Signal handler Yes
Thread Yes