snd_ctl_open()

Create a connection and handle to the specified control device

Synopsis:

#include <sys/asoundlib.h>

int snd_ctl_open( snd_ctl_t **handle,
                  int card );

Arguments:

handle: A pointer to a location in which snd_ctl_open() stores a handle for the card, which you need to pass to the other snd_ctl_* functions.
card: The card number.

Library:

libasound.so

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

Description:

The snd_ctl_open() function creates a new handle and opens a connection to the control interface for sound card number card (0-N). This handle may be used in all of the other snd_ctl_*() calls.

Returns:

Zero on success, or a negative value if an error occurs.

Errors:

-EACCES: Search permission is denied on a component of the path prefix, or the device exists and the permissions specified are denied.
-EINTR: The open() operation was interrupted by a signal.
-EMFILE: Too many file descriptors are currently in use by this process.
-ENFILE: Too many files are currently open in the system.
-ENOENT: The named device doesn't exist.
-ENOMEM: No memory available for data structure.
-SND_ERROR_INCOMPATIBLE_VERSION: The audio driver version is incompatible with the client library that the application is using.

Classification:

QNX Neutrino

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