mirror of
https://github.com/LCTT/TranslateProject.git
synced 2024-12-23 21:20:42 +08:00
336 lines
7.6 KiB
Markdown
336 lines
7.6 KiB
Markdown
使用 Node.js 构建交互式命令行工具
|
||
======
|
||
|
||
> 使用 Node.js 构建一个根据询问创建文件的命令行工具。
|
||
|
||
|
||
|
||
当用于构建命令行界面（CLI）时，Node.js 十分有用。在这篇文章中，我将会教你如何使用 [Node.js][1] 来构建一个问一些问题并基于回答创建一个文件的命令行工具。
|
||
|
||
### 开始
|
||
|
||
首先，创建一个新的 [npm][2] 包（NPM 是 JavaScript 包管理器）。
|
||
|
||
```
|
||
mkdir my-script
|
||
cd my-script
|
||
npm init
|
||
```
|
||
|
||
NPM 将会问一些问题。随后，我们需要安装一些包。
|
||
|
||
```
|
||
npm install --save chalk figlet inquirer shelljs
|
||
```
|
||
|
||
这是我们需要的包：
|
||
|
||
* Chalk：正确设定终端的字符样式
|
||
* Figlet：使用普通字符制作大字母的程序（LCTT 译注：使用标准字符，拼凑出图片）
|
||
* Inquirer：通用交互式命令行用户界面的集合
|
||
* ShellJS：Node.js 版本的可移植 Unix Shell 命令行工具
|
||
|
||
### 创建一个 index.js 文件
|
||
|
||
现在我们要使用下述内容创建一个 `index.js` 文件。
|
||
|
||
```
|
||
#!/usr/bin/env node
|
||
|
||
const inquirer = require("inquirer");
|
||
const chalk = require("chalk");
|
||
const figlet = require("figlet");
|
||
const shell = require("shelljs");
|
||
```
|
||
|
||
### 规划命令行工具
|
||
|
||
在我们写命令行工具所需的任何代码之前，做计划总是很棒的。这个命令行工具只做一件事：**创建一个文件**。
|
||
|
||
它将会问两个问题：文件名是什么以及文件后缀名是什么？然后创建文件，并展示一个包含了所创建文件路径的成功信息。
|
||
|
||
```
|
||
// index.js
|
||
|
||
const run = async () => {
|
||
// show script introduction
|
||
// ask questions
|
||
// create the file
|
||
// show success message
|
||
};
|
||
|
||
run();
|
||
```
|
||
|
||
第一个函数只是该脚本的介绍。让我们使用 `chalk` 和 `figlet` 来把它完成。
|
||
|
||
```
|
||
const init = () => {
|
||
console.log(
|
||
chalk.green(
|
||
figlet.textSync("Node JS CLI", {
|
||
font: "Ghost",
|
||
horizontalLayout: "default",
|
||
verticalLayout: "default"
|
||
})
|
||
)
|
||
);
|
||
}
|
||
|
||
const run = async () => {
|
||
// show script introduction
|
||
init();
|
||
|
||
// ask questions
|
||
// create the file
|
||
// show success message
|
||
};
|
||
|
||
run();
|
||
```
|
||
|
||
然后，我们来写一个函数来问问题。
|
||
|
||
```
|
||
const askQuestions = () => {
|
||
const questions = [
|
||
{
|
||
name: "FILENAME",
|
||
type: "input",
|
||
message: "What is the name of the file without extension?"
|
||
},
|
||
{
|
||
type: "list",
|
||
name: "EXTENSION",
|
||
message: "What is the file extension?",
|
||
choices: [".rb", ".js", ".php", ".css"],
|
||
filter: function(val) {
|
||
return val.split(".")[1];
|
||
}
|
||
}
|
||
];
|
||
return inquirer.prompt(questions);
|
||
};
|
||
|
||
// ...
|
||
|
||
const run = async () => {
|
||
// show script introduction
|
||
init();
|
||
|
||
// ask questions
|
||
const answers = await askQuestions();
|
||
const { FILENAME, EXTENSION } = answers;
|
||
|
||
// create the file
|
||
// show success message
|
||
};
|
||
```
|
||
|
||
注意，常量 `FILENAME` 和 `EXTENSIONS` 来自 `inquirer` 包。
|
||
|
||
下一步将会创建文件。
|
||
|
||
```
|
||
const createFile = (filename, extension) => {
|
||
const filePath = `${process.cwd()}/${filename}.${extension}`
|
||
shell.touch(filePath);
|
||
return filePath;
|
||
};
|
||
|
||
// ...
|
||
|
||
const run = async () => {
|
||
// show script introduction
|
||
init();
|
||
|
||
// ask questions
|
||
const answers = await askQuestions();
|
||
const { FILENAME, EXTENSION } = answers;
|
||
|
||
// create the file
|
||
const filePath = createFile(FILENAME, EXTENSION);
|
||
|
||
// show success message
|
||
};
|
||
```
|
||
|
||
最后，重要的是，我们将展示成功信息以及文件路径。
|
||
|
||
```
|
||
const success = (filepath) => {
|
||
console.log(
|
||
chalk.white.bgGreen.bold(`Done! File created at ${filepath}`)
|
||
);
|
||
};
|
||
|
||
// ...
|
||
|
||
const run = async () => {
|
||
// show script introduction
|
||
init();
|
||
|
||
// ask questions
|
||
const answers = await askQuestions();
|
||
const { FILENAME, EXTENSION } = answers;
|
||
|
||
// create the file
|
||
const filePath = createFile(FILENAME, EXTENSION);
|
||
|
||
// show success message
|
||
success(filePath);
|
||
};
|
||
```
|
||
|
||
|
||
来让我们通过运行 `node index.js` 来测试这个脚本，这是我们得到的：
|
||
|
||
|
||
|
||
### 完整代码
|
||
|
||
下述代码为完整代码：
|
||
|
||
```
|
||
#!/usr/bin/env node
|
||
|
||
const inquirer = require("inquirer");
|
||
const chalk = require("chalk");
|
||
const figlet = require("figlet");
|
||
const shell = require("shelljs");
|
||
|
||
const init = () => {
|
||
console.log(
|
||
chalk.green(
|
||
figlet.textSync("Node JS CLI", {
|
||
font: "Ghost",
|
||
horizontalLayout: "default",
|
||
verticalLayout: "default"
|
||
})
|
||
)
|
||
);
|
||
};
|
||
|
||
const askQuestions = () => {
|
||
const questions = [
|
||
{
|
||
name: "FILENAME",
|
||
type: "input",
|
||
message: "What is the name of the file without extension?"
|
||
},
|
||
{
|
||
type: "list",
|
||
name: "EXTENSION",
|
||
message: "What is the file extension?",
|
||
choices: [".rb", ".js", ".php", ".css"],
|
||
filter: function(val) {
|
||
return val.split(".")[1];
|
||
}
|
||
}
|
||
];
|
||
return inquirer.prompt(questions);
|
||
};
|
||
|
||
const createFile = (filename, extension) => {
|
||
const filePath = `${process.cwd()}/${filename}.${extension}`
|
||
shell.touch(filePath);
|
||
return filePath;
|
||
};
|
||
|
||
const success = filepath => {
|
||
console.log(
|
||
chalk.white.bgGreen.bold(`Done! File created at ${filepath}`)
|
||
);
|
||
};
|
||
|
||
const run = async () => {
|
||
// show script introduction
|
||
init();
|
||
|
||
// ask questions
|
||
const answers = await askQuestions();
|
||
const { FILENAME, EXTENSION } = answers;
|
||
|
||
// create the file
|
||
const filePath = createFile(FILENAME, EXTENSION);
|
||
|
||
// show success message
|
||
success(filePath);
|
||
};
|
||
|
||
run();
|
||
```
|
||
|
||
### 使用这个脚本
|
||
|
||
想要在其它地方执行这个脚本，在你的 `package.json` 文件中添加一个 `bin` 部分，并执行 `npm link`：
|
||
|
||
```
|
||
{
|
||
"name": "creator",
|
||
"version": "1.0.0",
|
||
"description": "",
|
||
"main": "index.js",
|
||
"scripts": {
|
||
"test": "echo \"Error: no test specified\" && exit 1",
|
||
"start": "node index.js"
|
||
},
|
||
"author": "",
|
||
"license": "ISC",
|
||
"dependencies": {
|
||
"chalk": "^2.4.1",
|
||
"figlet": "^1.2.0",
|
||
"inquirer": "^6.0.0",
|
||
"shelljs": "^0.8.2"
|
||
},
|
||
"bin": {
|
||
"creator": "./index.js"
|
||
}
|
||
}
|
||
```
|
||
|
||
执行 `npm link` 使得这个脚本可以在任何地方调用。
|
||
|
||
这就是是当你运行这个命令时的结果。
|
||
|
||
```
|
||
/usr/bin/creator -> /usr/lib/node_modules/creator/index.js
|
||
/usr/lib/node_modules/creator -> /home/hugo/code/creator
|
||
```
|
||
|
||
这会连接 `index.js` 作为一个可执行文件。这是完全可能的，因为这个 CLI 脚本的第一行是 `#!/usr/bin/env node`。
|
||
|
||
现在我们可以通过执行如下命令来调用。
|
||
|
||
```
|
||
$ creator
|
||
```
|
||
|
||
### 总结
|
||
|
||
正如你所看到的，Node.js 使得构建一个好的命令行工具变得非常简单。如果你希望了解更多内容，查看下列包。
|
||
|
||
* [meow][3]：一个简单的命令行助手工具
|
||
* [yargs][4]：一个命令行参数解析工具
|
||
* [pkg][5]：将你的 Node.js 程序包装在一个可执行文件中。
|
||
|
||
在评论中留下你关于构建命令行工具的经验吧！
|
||
|
||
--------------------------------------------------------------------------------
|
||
|
||
via: https://opensource.com/article/18/7/node-js-interactive-cli
|
||
|
||
作者：[Hugo Dias][a]
|
||
选题：[lujun9972](https://github.com/lujun9972)
|
||
译者：[bestony](https://github.com/bestony)
|
||
校对：[wxy](https://github.com/wxy)
|
||
|
||
本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出
|
||
|
||
[a]:https://opensource.com/users/hugodias
|
||
[1]:https://nodejs.org/en/
|
||
[2]:https://www.npmjs.com/
|
||
[3]:https://github.com/sindresorhus/meow
|
||
[4]:https://github.com/yargs/yargs
|
||
[5]:https://github.com/zeit/pkg
|