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.
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