Resize the png file within the same directory into three different size that fit the iOS universal imageset

resizeToFit.sh

writeToJson(){
	rm $1.imageset/Contents.json
	echo "{
	  \"images\" : [
	    {
	      \"idiom\" : \"universal\",
	      \"filename\" : \"[email protected]\",
	      \"scale\" : \"1x\"
	    },
	    {
	      \"idiom\" : \"universal\",
	      \"filename\" : \"[email protected]\",
	      \"scale\" : \"2x\"
	    },
	    {
	      \"idiom\" : \"universal\",
	      \"filename\" : \"[email protected]\",
	      \"scale\" : \"3x\"
	    }
	  ],
	  \"info\" : {
	    \"version\" : 1,
	    \"author\" : \"xcode\"
	  }
	}" >> $1.imageset/Contents.json
}

resize(){
	sips -z 72 72 $1.png --out [email protected]
	sips -z 48 48 $1.png --out [email protected]
	sips -z 24 24 $1.png --out [email protected]
}

copyToFolder(){
	mkdir $1.imageset
	cp [email protected] ./$1.imageset/
	cp [email protected] ./$1.imageset/
	cp [email protected] ./$1.imageset/
	rm [email protected]
	rm [email protected]
	rm [email protected]
}

for file in `ls *.png` 
do
	resize ${file%.png}
	copyToFolder ${file%.png}
	DIR="./${file%.png}"
	writeToJson $DIR ${file%.png}
done