问题
I'd like to use WebUSB to read and write files to a flash drive, or better, write arbitrary bits like unix's dd. Is this possible, or is only serial-like communication supported?
回答1:
It cannot. USB mass storage devices are claimed by the system's generic USB mass storage class driver and are therefore unavailable to the browser.
来源：https://stackoverflow.com/questions/49162692/can-webusb-transfer-files-to-a-usb-mass-storage-device-or-act-like-dd