Let’s talk about how Node uses the file system module

Node.js is an open source runtime environment that provides a platform for writing server-side JavaScript code. In Node.js, accessing the file system is a very common task. This article explains how to access the file system using Node.js, including how to find files.

1. File path

In Node.js, you need to use a path to access the file system. A path is a string that specifies the location of a file or directory in the file system. In Windows systems, the path uses the backslash "\" delimiter, for example: "C:\Users\UserName\Desktop\example.txt". In Unix systems, paths use forward slash "/" delimiters, for example: "/home/username/example.txt".

2. Relative paths and absolute paths

There are two types of file paths in Node.js: relative paths and absolute paths.

A relative path is a path relative to the current working directory. For example, if the current working directory is "/home/username", then the relative path "example.txt" will point to "/home/username/example.txt". If the current working directory is "/home/username/test", then the relative path "../example.txt" will point to "/home/username/example.txt".

The absolute path is the complete path starting from the root directory of the file system. For example, the absolute path "/home/username/example.txt" will point to "/home/username/example.txt".

3. Using the path module

Node.js provides a built-in "path" module that can be used to manipulate file paths. This module helps us create, parse and normalize paths.

To use the path module, we first need to import it into our code:

const path = require('path');

We can then use the methods provided by the path module to handle paths. For example, we can use the "path.join()" method to splice paths:

const newPath = path.join('/home', 'username', 'example.txt');
// newPath将等于"/home/username/example.txt"

4. Using the file system module

Node.js also provides a built-in " fs" module, which can be used to operate file systems. This module helps us read, write and delete files.

To use the file system module, we first need to import it into our code:

const fs = require('fs');

We can then use the methods provided by the file system module to manipulate files. For example, we can use the "fs.readFile()" method to read the file content:

fs.readFile('/home/username/example.txt', (err, data) => {
  if (err) throw err;
  console.log(data);
});

5. Conclusion

Accessing the file system in Node.js is a common task. Using a file path, we can specify the location of a file or directory in the file system. Using the path module we can create, parse and normalize paths. Using the file system module we can read, write and delete files. Understanding these concepts and techniques will be very useful when writing Node.js code.

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