Methods for detecting USB devices being plugged in or removed and calling selectors to process them. See USBTest.m for an example.
Compile with:
clang -framework CoreFoundation -framework Foundation -framework Cocoa -framework AppKit -framework IOKit -lobjc -Wall -Werror -arch YOUR_ARCH_HERE USBDetectionDetect.m USBDetectionDevice.m USBTest.m -o USBTest
Releases are built as universal binaries with compiled support for ppc750, ppc7400, ppc7450, ppc970, i386, x86_64, x86_64h, and arm64 per https://tenfourfox.blogspot.com/2020/06/the-super-duper-universal-binary.html and combined with lipo.