Another go at the Mac Makefile

Makefile

@@ -126,6 +126,8 @@ LDFLAGS_AS = $(LDFLAGS) -shared $(START_GROUP) -lpthread $(EXTRA_LIB) -lssl -lcr
 
 ifeq ($(OSTYPE),Linux)
 
+SED_COMMAND = sed -i "s/\#\#MQTTCLIENT_VERSION_TAG\#\#/${release.version}/g; s/\#\#MQTTCLIENT_BUILD_TAG\#\#/${build.level}/g" 
+
 MQTTCLIENT_INIT = MQTTClient_init
 MQTTASYNC_INIT = MQTTAsync_init
 START_GROUP = -Wl,--start-group
@@ -140,6 +142,8 @@ LDFLAGS_AS += -Wl,-soname,lib${MQTTLIB_AS}.so.${MAJOR_VERSION} -Wl,-no-whole-arc
 
 else ifeq ($(OSTYPE),Darwin)
 
+SED_COMMAND = sed -i "" -e "s/\#\#MQTTCLIENT_VERSION_TAG\#\#/${release.version}/g" -e "s/\#\#MQTTCLIENT_BUILD_TAG\#\#/${build.level}/g" 
+
 MQTTCLIENT_INIT = _MQTTClient_init
 MQTTASYNC_INIT = _MQTTAsync_init
 START_GROUP =
@@ -186,29 +190,25 @@ ${ASYNC_SAMPLES}: ${blddir}/samples/%: ${srcdir}/samples/%.c $(MQTTLIB_A_TARGET)
 	${CC} -o $@ $< -l${MQTTLIB_A} ${FLAGS_EXE}
 
 ${MQTTLIB_C_TARGET}: ${SOURCE_FILES_C} ${HEADERS_C}
-	sed -i 's/##MQTTCLIENT_VERSION_TAG##/${release.version}/g' $(srcdir)/MQTTClient.c
-	sed -i 's/##MQTTCLIENT_BUILD_TAG##/${build.level}/g' $(srcdir)/MQTTClient.c
+	$(SED_COMMAND) $(srcdir)/MQTTClient.c
 	${CC} ${CCFLAGS_SO} -o $@ ${SOURCE_FILES_C} ${LDFLAGS_C}
 	-ln -s lib$(MQTTLIB_C).so.${VERSION}  ${blddir}/lib$(MQTTLIB_C).so.${MAJOR_VERSION}
 	-ln -s lib$(MQTTLIB_C).so.${MAJOR_VERSION} ${blddir}/lib$(MQTTLIB_C).so
 
 ${MQTTLIB_CS_TARGET}: ${SOURCE_FILES_CS} ${HEADERS_C}
-	sed -i 's/##MQTTCLIENT_VERSION_TAG##/${release.version}/g' $(srcdir)/MQTTClient.c
-	sed -i 's/##MQTTCLIENT_BUILD_TAG##/${build.level}/g' $(srcdir)/MQTTClient.c
+	$(SED_COMMAND) $(srcdir)/MQTTClient.c
 	${CC} ${CCFLAGS_SO} -o $@ ${SOURCE_FILES_CS} -DOPENSSL ${LDFLAGS_CS}
 	-ln -s lib$(MQTTLIB_CS).so.${VERSION}  ${blddir}/lib$(MQTTLIB_CS).so.${MAJOR_VERSION}
 	-ln -s lib$(MQTTLIB_CS).so.${MAJOR_VERSION} ${blddir}/lib$(MQTTLIB_CS).so
 
 ${MQTTLIB_A_TARGET}: ${SOURCE_FILES_A} ${HEADERS_A}
-	sed -i "s/##MQTTCLIENT_VERSION_TAG##/${release.version}/g" $(srcdir)/MQTTAsync.c
-	sed -i "s/##MQTTCLIENT_BUILD_TAG##/${build.level}/g" $(srcdir)/MQTTAsync.c
+	$(SED_COMMAND) $(srcdir)/MQTTAsync.c
 	${CC} ${CCFLAGS_SO} -o $@ ${SOURCE_FILES_A} ${LDFLAGS_A}
 	-ln -s lib$(MQTTLIB_A).so.${VERSION}  ${blddir}/lib$(MQTTLIB_A).so.${MAJOR_VERSION}
 	-ln -s lib$(MQTTLIB_A).so.${MAJOR_VERSION} ${blddir}/lib$(MQTTLIB_A).so
 
 ${MQTTLIB_AS_TARGET}: ${SOURCE_FILES_AS} ${HEADERS_A}
-	sed -i "s/##MQTTCLIENT_VERSION_TAG##/${release.version}/g" $(srcdir)/MQTTAsync.c 
-	sed -i "s/##MQTTCLIENT_BUILD_TAG##/${build.level}/g" $(srcdir)/MQTTAsync.c
+	$(SED_COMMAND) $(srcdir)/MQTTAsync.c 
 	${CC} ${CCFLAGS_SO} -o $@ ${SOURCE_FILES_AS} -DOPENSSL ${LDFLAGS_AS}
 	-ln -s lib$(MQTTLIB_AS).so.${VERSION}  ${blddir}/lib$(MQTTLIB_AS).so.${MAJOR_VERSION}
 	-ln -s lib$(MQTTLIB_AS).so.${MAJOR_VERSION} ${blddir}/lib$(MQTTLIB_AS).so