setxattr(2) on macOS
The text 4f9982aecdd7, 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.
set an extended attribute value