snd_mixer_read()

Read pending mixer events

Synopsis:

#include <sys/asoundlib.h>

int snd_mixer_read( snd_mixer_t * handle, 
                    snd_mixer_callbacks_t * callbacks );

Library:

libasound.so

Description:

The snd_mixer_read() function reads pending mixer events from the mixer handle. As each event is read, the list of callbacks is checked for a handler for this event. If a match is found, the callback is invoked. This function is usually called on the return of the select() library call.

Returns:

The number of events read form the handle, or a negative value on error.

Errors:

-EBADF

Invalid file descriptor, filedes, open for reading.

-EINTR

The read operation was interrupted by a signal, and either no data was transferred, or the resource manager responsible for that file doesn't report partial transfers.

-EIO

An event I/O error occurred.

Examples:

See the example in Registering your application in the Controlling volume and balance chapter.

Classification:

ALSA

See also:

snd_mixer_close(), snd_mixer_open()