allow nc to build on linux and os x

apps/nc/compat/socket.c

@@ -0,0 +1,29 @@
+#define SOCKET_FLAGS_PRIV
+
+#include <sys/socket.h>
+
+#ifdef NEED_SOCKET_FLAGS
+
+#include <fcntl.h>
+
+int
+_socket(int domain, int type, int protocol)
+{
+	int s = socket(domain, type & ~(SOCK_CLOEXEC | SOCK_NONBLOCK), protocol);
+	int flags;
+	if (s == -1)
+		return s;
+
+	if (type & SOCK_CLOEXEC) {
+		flags = fcntl(s, F_GETFD);
+		fcntl(s, F_SETFD, flags | FD_CLOEXEC);
+	}
+
+	if (type & SOCK_NONBLOCK) {
+		flags = fcntl(s, F_GETFL);
+		fcntl(s, F_SETFL, flags | O_NONBLOCK);
+	}
+	return s;
+}
+
+#endif