3.2 KiB
Gopher Interface Devices (USB HID)
The hid package is a cross platform library for accessing and communicating with USB Human Interface
Devices (HID). It is an alternative package to gousb for use
cases where devices support this ligher mode of operation (e.g. input devices, hardware crypto wallets).
The package wraps hidapi for accessing OS specific USB HID APIs
directly instead of using low level USB constructs, which might have permission issues on some platforms.
On Linux the package also wraps libusb. Both of these dependencies
are vendored directly into the repository and wrapped using CGO, making the hid package self-contained
and go-gettable.
Supported platforms at the moment are Linux, macOS and Windows (exclude constraints are also specified for Android and iOS to allow smoother vendoring into cross platform projects).
Cross-compiling
Using go get the embedded C library is compiled into the binary format of your host OS. Cross compiling to a different platform or architecture entails disabling CGO by default in Go, causing device enumeration hid.Enumerate() to yield no results.
To cross compile a functional version of this library, you'll need to enable CGO during cross compilation via CGO_ENABLED=1 and you'll need to install and set a cross compilation enabled C toolkit via CC=your-cross-gcc.
Acknowledgements
Although the hid package is an implementation from scratch, it was heavily inspired by the existing
go.hid library, which seems abandoned since 2015; is incompatible
with Go 1.6+; and has various external dependencies. Given its inspirational roots, I thought it important
to give credit to the author of said package too.
Wide character support in the hid package is done via the gowchar
library, unmaintained since 2013; non buildable with a modern Go release and failing go vet checks. As
such, gowchar was also vendored in inline (copyright headers and origins preserved).
License
The components of hid are licensed as such:
hidapiis released under the 3-clause BSD license.libusbis released under the GNU LGPL 2.1license.go.hidis released under the 2-clause BSD license.gowcharis released under the 3-clause BSD license.
Given the above, hid is licensed under GNU LGPL 2.1 or later on Linux and 3-clause BSD on other platforms.