openusb_set_debug
handle
- An openusb instance handle, obtained in openusb_init
.
level
- Not used. Reserved.
flags
- Not used in this release. Reserved.
callback
- Application supplied debug routine.
Application can call openusb_set_debug()
to enable tracing
of openusb with increasing level of detail. callback is application defined debug function.
If it is NULL, the library embedded debug function is used and debug messages, if any and
debug level set properly, will go to stderr.
This operation will override the USB_DEBUG
environment variable, if set.