watch gulp task

verify.sh

#! /bin/bash
while true
do
	cwd=$(pwd)
	FILES=$cwd/src/**/**/*	// renplace with your path
	current=`date +%s`
	for f in $FILES
	do
		last_modified=`stat -c %Y $f`
		if [ $(($current-$last_modified)) -lt 2 ]; then
			gulp build-custom // your cgulp command
			break;
		fi
	done
	sleep 1s
done