libcurl-share(3) on macOS

The text 5598917a26f1, as Mac OS X 10.6.8, Mac OS X 10.6.7, Mac OS X 10.6.6, Mac OS X 10.6.5, Mac OS X 10.6.4, Mac OS X 10.6.3 shipped it.

how to use the share interface

libcurl-share(3) on macOS now