gulpfile.js

var gulp = require('gulp');
var watch = require('gulp-watch');
var shell = require('gulp-shell');

// reload task
gulp.task('reload', shell.task([
  'echo hello' // do your shell commands here - works as an array of commands if you want to add more
]));
 
// watch files
gulp.task('watch', function() {
    gulp.watch('index.js', ['reload']);
});

// Default Task
gulp.task('default', ['reload', 'watch']);