usbhidctl
compares the names of items specified on the command line against the human
interface items reported by the USB device.
Each human interface item is mapped from its native form to a human readable
name, using the HID usage table file.
Command line items are compared with the generated item names,
and the USB HID device is operated on when a match is found.
Each human interface item is named by the
"page"
it appears in, the
"usage"
within that page, and the list of
"collections"
containing the item.
Each collection in turn is also identified by page, and
the usage within that page.
On the
usbhidctl
command line the page name is separated from the usage name with the character
' amp;:'.
The collections are separated by the character
' amp;.'.
Some devices give the same name to more than one item.
usbhidctl
supports isolating each item by appending a
' amp;#'.
character and a decimal item instance number, starting at zero.
