List of connected devices.
Name of input file.
If nonzero, input is accepted when playback is active.
Name of output file.
If nonzero, playback is active.
If nonzero, recording is active.
Name of save file.
|info||print information about the device|
|playback-start||play back recorded I/O|
|recorder-start||record input to file|
|status||print status of the device|