Node.js fs-extra ensureLinkSync()函数

ensureLinkSync()函数是 ensureLink() 的同步版本。该函数确保两个给定文件之间的链接存在。源文件需要已经存在，否则函数会抛出错误。如果目标文件的目录结构不存在，那么它将由函数创建，并在源文件和目标文件之间建立链接。 createLinkSync ()也可以用来代替 ensureLinkSync()。

句法：

ensureLinkSync(srcPath, destPath)
// OR
createLinkSync(srcPath, destPath)

参数：

srcPath：它是一个字符串，包含要与另一个文件链接的文件的路径。
destPath：它是一个字符串，其中包含将链接到 srcPath 中指定的文件的另一个文件的路径。

返回值：它不返回任何东西。

按照以下步骤实现该函数：

可以使用以下命令安装该模块。
```
npm install fs-extra
```
安装模块后，您可以使用此命令检查已安装模块的版本。
```
npm ls fs-extra
```
创建一个名为 index.js 的文件，并使用以下命令在文件中要求 fs-extra 模块。
```
const fs = require('fs-extra');
```
要运行该文件，请在终端中写入以下命令。
```
node index.js
```

项目结构：项目结构将如下所示。

示例 1：

index.js

// Requiring module
const fs = require("fs-extra");
  
// source file path
// File needs to exist
const srcPath = "file.txt";
// destination file path
// This file exists already
const destPath = "dest/file.txt";
  
// Function to check
// if destination file
// exists or not
const fileExists = (path) => {
  if (fs.existsSync(path)) return "Destination file exists";
  return "Destination file do not exists";
};
  
// Before function call
const before = fileExists(destPath);
console.log(`Before function call ${before}`);
  
// Function Call
fs.ensureLinkSync(srcPath, destPath);
  
// After function call
const after = fileExists(destPath);
console.log(
  `After function call ${after} and Link is successfully established!!`
);

Javascript

// Requiring module
const fs = require("fs-extra");
  
// source file path
// File needs to exist
const srcPath = "file.txt";
// destination file path
// This file do not exists
// so it will be created
// bt function
const destPath = "destination/dest/file.txt";
  
// Function to check
// if destination file
// exists or not
const fileExists = (path) => {
  if (fs.existsSync(path)) return "Destination file exists";
  return "Destination file do not exists";
};
  
// Before function call
const before = fileExists(destPath);
console.log(`Before function call ${before}`);
  
// Function Call
fs.ensureLinkSync(srcPath, destPath);
  
// After function call
const after = fileExists(destPath);
console.log(
  `After function call ${after} and Link is successfully established!!`
);

输出：

示例 2：

Javascript

// Requiring module
const fs = require("fs-extra");
  
// source file path
// File needs to exist
const srcPath = "file.txt";
// destination file path
// This file do not exists
// so it will be created
// bt function
const destPath = "destination/dest/file.txt";
  
// Function to check
// if destination file
// exists or not
const fileExists = (path) => {
  if (fs.existsSync(path)) return "Destination file exists";
  return "Destination file do not exists";
};
  
// Before function call
const before = fileExists(destPath);
console.log(`Before function call ${before}`);
  
// Function Call
fs.ensureLinkSync(srcPath, destPath);
  
// After function call
const after = fileExists(destPath);
console.log(
  `After function call ${after} and Link is successfully established!!`
);

输出：

参考： https://github.com/jprichardson/node-fs-extra/blob/HEAD/docs/ensureLink-sync.md