snd_pcm_file_descriptor()

Return the file descriptor of the connection to the PCM interface

Synopsis:

#include <sys/asoundlib.h>

int snd_pcm_file_descriptor( snd_pcm_t *handle, 
                             int channel );

Arguments:

handle: The handle for the PCM device, which you must have opened by calling snd_pcm_open_name(), snd_pcm_open(), or snd_pcm_open_preferred().
channel: The channel; SND_PCM_CHANNEL_CAPTURE or SND_PCM_CHANNEL_PLAYBACK.

Library:

libasound.so

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

Description:

The snd_pcm_file_descriptor() function returns the file descriptor of the connection to the PCM interface.

You can use this file descriptor for the select() synchronous multiplexer function (see the QNX Neutrino C Library Reference).

Returns:

The file descriptor of the connection to the PCM interface on success, or a negative error code. The errno values are available in the errno.h file.

Errors:

-EINVAL: The state of handle is invalid, an invalid channel was provided as input, or an invalid state change occurred. You can call snd_pcm_channel_status() to check if the state change was invalid.

Classification:

QNX Neutrino

Safety:
Cancellation point	No
Interrupt handler	No
Signal handler	Yes
Thread	Read the Caveats

Caveats:

This function is not thread safe if handle (snd_pcm_t) is used across multiple threads.