libcurl-share(3) on macOS

The text 7b8ea6b658e4, as Mac OS X 10.8.5, Mac OS X 10.8.4, Mac OS X 10.8.3, Mac OS X 10.8.2, Mac OS X 10.8.1, Mac OS X 10.8 shipped it.

how to use the share interface

libcurl-share(3) on macOS now