title: know a usb device's endpoint
body: <p>Is there a bash command, a program or a libusb function (although I did not find one) which indicates me what are the OUT or IN endpoints of a usb device ?</p>
  
  <p>For example, bNumEndpoints of libusb_interface_descriptor (from libusb1.0 library) shows me my usb drive has 3 endpoints, but how can I know what is their idnumber ?</p>