gulpfile.js

var gulp            = require('gulp'),
    shell           = require('gulp-shell'),
    rename          = require('gulp-rename'),
    browserSync     = require('browser-sync').create();

/* dirs */
var	assetsDir			= 'assets',
    bowerDir			= 'node_modules',
    targetSass		= '_sass',
    targetCSS			= 'css',
    targetFont		= assetsDir + '/fonts',
    targetJs			= assetsDir + '/js';

// Task for building blog when something changed:
gulp.task('build', shell.task(['bundle exec jekyll build --watch']));
// Or if you don't use bundle:
// gulp.task('build', shell.task(['jekyll build --watch']));

// Task for serving blog with Browsersync
gulp.task('serve', function () {
    browserSync.init({
        server: {baseDir: '_site/'},
        open: false
    });
    gulp.watch('_site/**/*.*').on('change', browserSync.reload);
});

gulp.task('default', ['build', 'serve']);

gulp.task('copy_files', function() {
    gulp.src(bowerDir + '/reveal.js/lib/**/*')
        .pipe(gulp.dest(assetsDir + '/lib'));
    gulp.src(bowerDir + '/reveal.js/css/theme/source/**/*')
        .pipe(gulp.dest(targetSass + '/theme/source'));
    gulp.src(bowerDir + '/reveal.js/css/theme/template/**/*')
        .pipe(gulp.dest(targetSass + '/theme/template'));
    gulp.src(bowerDir + '/reveal.js/plugin/**/*')
        .pipe(gulp.dest(assetsDir + '/plugin'));
    gulp.src(bowerDir + '/reveal.js/js/reveal.js')
        .pipe(gulp.dest(targetJs));
    gulp.src(bowerDir + '/reveal.js/css/reveal.scss')
        .pipe(rename('_reveal.scss'))
        .pipe(gulp.dest(targetSass));
    gulp.src(bowerDir + '/reveal.js/lib/css/zenburn.css')
        .pipe(rename('_zenburn.scss'))
        .pipe(gulp.dest(targetSass));
    gulp.src(bowerDir + '/reveal.js/css/print/paper.css')
        .pipe(rename('/print/paper.css'))
        .pipe(gulp.dest(targetCSS));
    gulp.src(bowerDir + '/reveal.js/css/print/pdf.css')
        .pipe(rename('/print/pdf.css'))
        .pipe(gulp.dest(targetCSS));
});