snd_ctl_open()

Open a control device

Synopsis:

#include <sys/asoundlib.h>

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

Library:

libasound.a

Description:

The snd_ctl_open() function creates a new handle and opens a connection to the sound control interface for a 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 uses.

Examples:

See the example in Opening the mixer in the Controlling volume and balance chapter.

Classification:

ALSA

See also:

snd_ctl_close()