diffrent usage of sed between linux and osx

Makefile

@@ -1,6 +1,13 @@
 VERSION := 0.1.8.2
 RELEASEPATH = release/$(FULLVERSION)
 
+UNAME := $(shell uname)
+ifeq ($(UNAME), Darwin)
+	SED=sed -i ""
+else
+	SED=sed -i
+endif
+
 default: 2.3.2
 
 all: 2.3.2 2.3.5
@@ -17,13 +24,13 @@ build:
 	cp example.yml $(RELEASEPATH)
 	cp LICENSE $(RELEASEPATH)
 	cp bin/hangout $(RELEASEPATH)/bin
-	sed -i "" 's/\<elasticsearch-version\>[0-9.]*/<elasticsearch-version\>$(ESVERSION)/' pom.xml
+	$(SED) 's/\<elasticsearch-version\>[0-9.]*/<elasticsearch-version\>$(ESVERSION)/' pom.xml
 	git rev-parse --short HEAD > $(RELEASEPATH)/VERSION
 	mvn clean package
 	mvn dependency:copy-dependencies
 	cp target/hangout-$(VERSION).jar $(RELEASEPATH)/lib
 	cp target/dependency/* $(RELEASEPATH)/vender
-	sed -i '' 's/X.X.X/$(VERSION)/' $(RELEASEPATH)/bin/hangout
+	$(SED) 's/X.X.X/$(VERSION)/' $(RELEASEPATH)/bin/hangout
 	tar -cf release/$(FULLVERSION).tar -C release $(FULLVERSION)
 	git reset --hard