usb

how to make a usb to transfer the files in it to the pc to a specify location when is plug into the pc

Interesting question. You could make a standard keyboard HID device, but instead of having keys, it would send the same keystrokes when it's plugged in automatically.

Ok, what keystrokes am I talking about? Lets clarify things up with an example. In this example, we want to usb stick to write word hello to file /home/retardix/hello.txt. The stick would emulate following keypresses:

[ALT+F2]
konsole
[ENTER]
echo hello > hello.txt

Ok, this is pretty simple. Binary data could be written, for example, by piping echo to xxd -r or base64 -d.