吞咽:吞咽未定义 [英] GULP: gulp is not defined

问题描述

如下面的屏幕截图所示，我无法运行 gulp 来连接 JavaScript 文件.它说 gulp 没有定义.

As shown in the screen shot below I am not able to run gulp to concat the JavaScript files. Its saying that gulp is not defined.

我尝试了以下命令:

npm install -g gulp
npm install gulp
npm install gulp --save-dev

我还设置了如下环境变量:

I have also set the environment variables as following:

C:Users<user>AppDataRoaming
pm;C:Python27;C:Users<user>AppDataRoaming
pm
ode_modules;C:Users<user>AppDataRoaming
pm
ode_modulesgulp;

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


//script paths
var jsFiles = 'scripts/*.js',  
    jsDest = 'dist/scripts';

gulp.task('scripts', function() {  
    return gulp.src(jsFiles)
        .pipe(concat('scripts.js'))
        .pipe(gulp.dest(jsDest));
});

推荐答案

你只需要安装并且需要 gulp locally，你可能只需要全局安装

you just need to install and require gulp locally, you probably only installed it globally

在命令行

cd <project-root> && npm install --save-dev gulp

在你的 gulpfile.js 中

In your gulpfile.js

var gulp = require('gulp'); 

这是与命令行依赖项(您全局安装的)不同的依赖项.更具体地说，它是同一个 NPM 包，但命令行程序通常会从 NPM 包中的不同入口点执行代码，然后 require('X') 将返回.

this is a different dependency than the command line dependency (that you installed globally). More specifically, it is the same NPM package, but the command line program will execute code usually from a different entry point in the NPM package then what require('X') will return.

如果我们转到 Github 上 Gulp 项目中的 package.json 文件，它会讲述整个故事:

If we go to the package.json file in the Gulp project on Github, it will tell the whole story:

{
  "name": "gulp",
  "description": "The streaming build system",
  "version": "3.9.1",
  "homepage": "http://gulpjs.com",
  "repository": "gulpjs/gulp",
  "author": "Fractal <[e-mail]> (http://wearefractal.com/)",
  "tags": [ ],
  "files": [ 
     // ...
   ],
  "bin": {
    "gulp": "./bin/gulp.js"
  },
  "man": "gulp.1",
  "dependencies": {
    // ...
  },
  "devDependencies": {
     // ...
  },
  "scripts": {
    "prepublish": "marked-man --name gulp docs/CLI.md > gulp.1",
    "lint": "eslint . && jscs *.js bin/ lib/ test/",
    "pretest": "npm run lint",
  },
  "engines": {
    "node": ">= 0.9"
  },
  "license": "MIT"
}

所以在命令行:

$ gulp default

会执行这个:

     "bin": {
        "gulp": "./bin/gulp.js"
      },

另一方面，代码中的 require('gulp') 将返回 this 的值:

on the other hand, require('gulp') in your code will return the value of this:

https://github.com/gulpjs/gulp/blob/master/index.js

通常我们会在 package.json 文件中看到:

normally we see this in a package.json file as:

"main": "index.js"

但由于这是默认设置，他们只是省略了它(这是愚蠢的 IMO，最好是明确的，但它们不是我见过的第一个采用蹩脚的速记路线的项目.

but since this is the default, they just omitted it (which is dumb IMO, better to be explicit, but they aren't the first project I have seen take the lame shorthand route.).

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