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snd_ctl_file_descriptor()
Get the control file descriptor
Synopsis:
#include <sys/asoundlib.h> int snd_ctl_file_descriptor( snd_ctl_t *handle );
Arguments:
- handle
- The handle for the control connection to the card. This must be a handle created by snd_ctl_open().
Library:
libasound.so
Description:
The snd_ctl_file_descriptor() function returns the file descriptor of the connection to the control interface.
You can use the file descriptor for the select() function (see the QNX Library Reference) for determining if something can be read or written. Your application should then call snd_ctl_read() if data is waiting to be read.
Returns:
The file descriptor of the connection to the control interface, or a negative value if an error occurs.
Errors:
- -EINVAL
- Invalid handle argument.
Classification:
QNX Neutrino
| Safety: | |
|---|---|
| Cancellation point | No |
| Interrupt handler | No |
| Signal handler | Yes |
| Thread | Yes |
See also:
snd_ctl_open(), snd_ctl_read()
select() in the QNX Library Reference
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