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 Neutrino C 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