Gulp command opens gulp.js in notepad instead of running it

Question

I installed it correctly I think.

My package.json

   {
      "name": "my-project",
      "version": "0.1.0",
      "devDependencies": {
        "gulp": "^3.8.11",
        "gulp-concat": "^2.5.2"
      }
    }

my gulp.js

var gulp = require('gulp');

    var concat = require('gulp-concat');

    gulp.task('scripts', function() {
        return gulp.src('js/*.js')
          .pipe(concat('main.js'))
          .pipe(gulp.dest('build/js'));
    });

    gulp.task('default', ['scripts']);

my folder are as follow :

ROOT/package.json
ROOT/gulp.js
ROOT/node-modules/   <-- my modules are here
ROOT/js/  <-- my js are here

When I run gulp in command line, being in the ROOT folder, gulp.js just opens in windows notepad and that's all..

Why is it doing that?

Answer 1

Two steps: Step-1) renaming gulp.js to gulpfile.js as exposed in answer above; Step-2) using npm install -g gulp-cli

Answer 2

problem solved by a simple action: renaming gulp.js to gulpfile.js (sigh..)