some portability improvements

c_src/GNUmakefile

@@ -0,0 +1,21 @@
+
+UNAME=$(shell uname)
+
+ifeq ($(UNAME),Darwin)
+	SHLIB_CFLAGS=-fPIC -bundle -flat_namespace -undefined suppress
+else
+	SHLIB_CFLAGS=-fPIC -shared
+endif
+
+CFLAGS +=-fPIC -I. $(shell erl -noinput -eval 'io:format("-I~s -I~s/erts-~s/include", [code:lib_dir(erl_interface, include), code:root_dir(), erlang:system_info(version)]), halt(0).')
+LDFLAGS +=$(shell erl -noinput -eval 'io:format("-L~s", [code:lib_dir(erl_interface, lib)]), halt(0).')
+
+all: ../priv/lib/gen_socket.so 
+
+clean: 
+	rm -f ../priv/lib/*.so
+	rm -f *.o
+
+../priv/lib/gen_socket.so: gen_socket.o
+	(test -d ../priv/lib || mkdir -p ../priv/lib)
+	$(CC) $(LDFLAGS) $(SHLIB_CFLAGS) -lei -lerl_interface gen_socket.o -o ../priv/lib/gen_socket.so

c_src/Makefile

@@ -1,11 +1,9 @@
-CFLAGS +=-fPIC -I. $(shell erl -noinput -eval 'io:format("-I~s -I~s/erts-~s/include", [code:lib_dir(erl_interface, include), code:root_dir(), erlang:system_info(version)]), halt(0).')
+# a stub makefile for BSD make.
+# just redirect to GNU make, which is commonly available as "gmake".
 
-all: ../priv/lib/gen_socket.so 
+TARGETS=all clean
 
-clean: 
-	rm -f ../priv/lib/*.so
-	rm -f *.o
-
-../priv/lib/gen_socket.so: gen_socket.o
-	(test -d ../priv/lib || mkdir -p ../priv/lib)
-	$(CC) $(LDFLAGS) -fPIC -shared -lei -lerl_interface gen_socket.o -o ../priv/lib/gen_socket.so
+.for T in ${TARGETS}
+${T}:
+	@gmake ${T}
+.endfor

c_src/gen_socket.c

@@ -35,6 +35,13 @@
  * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.
  */
+
+#include <sys/socket.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+
 #include "erl_nif.h"
 #include "erl_driver.h"
 #include "gen_socket.h"