My Grunt task

Gruntfile.js

module.exports = function(grunt) {

    grunt.registerTask('watch', [ 'watch' ]);

    grunt.initConfig({

        recess: {
            options: {
                compile: true,
            },
            dock: {
                options: {
                    compress: false
                },
                files: {
                    "css/style.css": "less/style.less",
                    "css/ie.css": "less/ie.less"
                }
            }
        },

        concat: {
            js: {
                options: {
                    separator: ';'
                },
                src: [
                    // 'assets/js/*.js'
                    'js/jquery.js',
                    'js/easing.js',
                    'js/jquery-color.js',
                    'js/imagesloaded.js',
                    'js/html5shiv.js',
                    'js/retina.js',
                    'js/init.js'
                ],
                dest: 'js/init.min.js'
            }
        },

        uglify: {
            options: {
                mangle: false
            },
            js: {
                files: {
                    'js/application.min.js': "js/application.js"
                }
            }
        },

        copy: {
            images: {
                expand: true,
                flatten: true,
                src: ['_content/*/*'],
                dest: 'images/',
                filter: 'isFile'
            }
        },

        watch: {
            image: {
                files: ['_content/*/*'],
                tasks: ['copy:images']
            },
            js: {
                files: ['js/*.js'],
                tasks: ['concat:js', 'uglify:js']
            },
            css: {
                files: ['less/*.less','less/*/*.less'],
                tasks: ['recess']
            },
        }

    });

    grunt.loadNpmTasks('grunt-contrib-concat');
    grunt.loadNpmTasks('grunt-contrib-copy');
    grunt.loadNpmTasks('grunt-contrib-uglify');
    grunt.loadNpmTasks('grunt-contrib-less');
    grunt.loadNpmTasks('grunt-recess');
    grunt.loadNpmTasks('grunt-contrib-watch');
};