1Notes on POSIX 2============== 3 4There are few instances where OpenSSL requires a POSIX C library, at least 5version 1-2008, or compatible enough functionality. 6 7There are exceptions, though, for platforms that do not have a POSIX 8library, or where there are quirks that need working around. A notable 9platform is Windows, where POSIX functionality may be available, but where 10the function names are prefixed with an underscore, and where some POSIX 11types are not present (such as `ssize_t`). 12 13Platforms that do have a POSIX library may still not have them accessible 14unless the following macros are defined: 15 16 _POSIX_C_SOURCE=200809L 17 _XOPEN_SOURCE=1 18 19This is, for example, the case when building with gcc or clang and using the 20flag `-ansi`. 21