+#define readsocket(s,b,n) recv((s),(b),(n),0)
+#define writesocket(s,b,n) send((s),(b),(n),0)
+#elif defined(__DJGPP__)
+#define WATT32
+#define get_last_socket_error() errno
+#define clear_socket_error() errno=0
+#define closesocket(s) close_s(s)
+#define readsocket(s,b,n) read_s(s,b,n)
+#define writesocket(s,b,n) send(s,b,n,0)
+#elif defined(MAC_OS_pre_X)
+#define get_last_socket_error() errno
+#define clear_socket_error() errno=0
+#define closesocket(s) MacSocket_close(s)
+#define readsocket(s,b,n) MacSocket_recv((s),(b),(n),true)
+#define writesocket(s,b,n) MacSocket_send((s),(b),(n))
+#elif defined(OPENSSL_SYS_VMS)
+#define get_last_socket_error() errno
+#define clear_socket_error() errno=0
+#define ioctlsocket(a,b,c) ioctl(a,b,c)
+#define closesocket(s) close(s)
+#define readsocket(s,b,n) recv((s),(b),(n),0)
+#define writesocket(s,b,n) send((s),(b),(n),0)
+#elif defined(OPENSSL_SYS_VXWORKS)
+#define get_last_socket_error() errno
+#define clear_socket_error() errno=0
+#define ioctlsocket(a,b,c) ioctl((a),(b),(int)(c))
+#define closesocket(s) close(s)
+#define readsocket(s,b,n) read((s),(b),(n))
+#define writesocket(s,b,n) write((s),(char *)(b),(n))
+#elif defined(OPENSSL_SYS_BEOS_R5)
+#define get_last_socket_error() errno
+#define clear_socket_error() errno=0
+#define FIONBIO SO_NONBLOCK
+#define ioctlsocket(a,b,c) setsockopt((a),SOL_SOCKET,(b),(c),sizeof(*(c)))
+#define readsocket(s,b,n) recv((s),(b),(n),0)
+#define writesocket(s,b,n) send((s),(b),(n),0)
+#elif defined(OPENSSL_SYS_NETWARE)
+#if defined(NETWARE_BSDSOCK)
+#define get_last_socket_error() errno
+#define clear_socket_error() errno=0
+#define closesocket(s) close(s)
+#define ioctlsocket(a,b,c) ioctl(a,b,c)
+#if defined(NETWARE_LIBC)
+#define readsocket(s,b,n) recv((s),(b),(n),0)
+#define writesocket(s,b,n) send((s),(b),(n),0)
+#else
+#define readsocket(s,b,n) recv((s),(char*)(b),(n),0)
+#define writesocket(s,b,n) send((s),(char*)(b),(n),0)
+#endif
+#else
+#define get_last_socket_error() WSAGetLastError()
+#define clear_socket_error() WSASetLastError(0)
+#define readsocket(s,b,n) recv((s),(b),(n),0)
+#define writesocket(s,b,n) send((s),(b),(n),0)
+#endif