+#include <openssl/e_os2.h>
+#if !defined(OPENSSL_SYS_MSDOS) && !defined(OPENSSL_SYS_VMS) && !defined(OPENSSL_SYS_WIN32)
+#ifdef OPENSSL_UNISTD
+# include OPENSSL_UNISTD
+#else
+# include <unistd.h>
+#endif
+/* If unistd.h defines _POSIX_VERSION, we conclude that we
+ * are on a POSIX system and have sigaction and termios. */
+#if defined(_POSIX_VERSION)
+
+# define SIGACTION
+# if !defined(TERMIOS) && !defined(TERMIO) && !defined(SGTTY)
+# define TERMIOS
+# endif
+
+#endif
+#endif
+
+/* #define SIGACTION */ /* Define this if you have sigaction() */
+