Method: LIBUSB::Device#open

Defined in:
lib/libusb/device.rb

#open ⇒ DevHandle

Open the device and obtain a device handle.

A handle allows you to perform I/O on the device in question. This is a non-blocking function; no requests are sent over the bus.

If called with a block, the handle is passed to the block and is closed when the block has finished.

You need proper device access:

  • Linux: read+write permissions to /dev/bus/usb/<bus>/<dev>

  • Windows: by installing a WinUSB-driver for the device (see README )

Returns:


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# File 'lib/libusb/device.rb', line 58

def open
  ppHandle = FFI::MemoryPointer.new :pointer
  res = Call.libusb_open(@pDev, ppHandle)
  LIBUSB.raise_error res, "in libusb_open" if res!=0
  handle = DevHandle.new self, ppHandle.read_pointer
  return handle unless block_given?
  begin
    yield handle
  ensure
    handle.close
  end
end