Gulp file example

gulpfile.json

var gulp = require('gulp');
var minifyCss = require('gulp-minify-css');
var gulpConcat = require('gulp-concat');
var uglify = require('gulp-uglify');
var notify = require('gulp-notify');

var cssFiles = [
    'public_html/res/css/bootstrap.css',
    'public_html/res/css/datetimepicker.css',
    'public_html/res/css/datepicker.css',
    'public_html/res/css/fonts.css'
];

var jsFiles =[
    'public_html/res/js/main.js',
    'public_html/res/js/jquery.js',
    'public_html/res/js/bootstrap.js'

];

gulp.task('minify-js', function() {
    return gulp.src(jsFiles)
        //.pipe(uglify())
        .pipe(gulpConcat('script.min.js'))
        .pipe(gulp.dest('public_html/res/js'))
        //.pipe(notify({ message: 'Finished minifying JavaScript'}))
        ;
});

gulp.task('minify-css', function() {
  return gulp.src(cssFiles)
    .pipe(minifyCss({
            keepSpecialComments: 0,
            advanced: false,
            aggressiveMerging: false
        }))
    .pipe(gulpConcat('style.min.css'))
    .pipe(gulp.dest('public_html/res/css'))
    //.pipe(notify('Finished minifying CSS'))
    ;

});

gulp.task('default', ['minify-css']);