getxattr(2) on macOS
The text 3d664a97b867, as Mac OS X 10.4.11.x86, Mac OS X 10.4.11.ppc, Mac OS X 10.4.9.x86, Mac OS X 10.4.9.ppc, Mac OS X 10.4.7.ppc, Mac OS X 10.4.6.ppc, Mac OS X 10.4.5.ppc, Mac OS X 10.4.4.ppc, Mac OS X 10.4.3, Mac OS X 10.4.2, Mac OS X 10.4.1, Mac OS X 10.4 shipped it.
get an extended attribute value