ملف gulp

cant work in cmd and say 'gulp' is not recognized as an internal or external command,operable program or batch file
picture cmd: http://pictub.club/image/sAksv6
picture for file gulpfile : http://pictub.club/image/sAJlui

الامر اشتغل شكر

there is code in package.json
{
  \"private\": true,
  \"scripts\": {
    \"prod\": \"gulp --production\",
    \"dev\": \"gulp watch\"
  },
  \"devDependencies\": {
    \"bootstrap-sass\": \"^3.3.7\",
    \"gulp\": \"^3.9.1\",
    \"jquery\": \"^3.1.0\",
    \"laravel-elixir\": \"^6.0.0-9\",
    \"laravel-elixir-vue-2\": \"^0.2.0\",
    \"laravel-elixir-webpack-official\": \"^1.0.2\",
    \"lodash\": \"^4.16.2\",
    \"vue\": \"^2.0.1\",
    \"vue-resource\": \"^1.0.3\"
  },
  \"dependencies\": {
    \"browserify\": \"^13.1.1\",
    \"gulp\": \"^3.9.1\",
    \"laravel-elixir-vue-2\": \"^0.2.0\",
    \"laravel-elixir-vueify\": \"^2.0.0\",
    \"lodash\": \"^4.17.2\",
    \"vue\": \"^2.1.4\",
    \"vue-resource\": \"^1.0.3\",
    \"vue-route\": \"^1.5.1\",
    \"vueify\": \"^9.4.0\"
  }
}