Unlock the Power of Deno’s File System

Writing Files in Deno

To write files in Deno, you’ll need to use the --allow-write flag. Deno provides three methods for writing files:

• writeTextFile: writes a string to a file
• writeFile: writes a byte array to a file
• open with writeAll: writes data to a file using a writable file stream

Each method has its own strengths and weaknesses, and choosing the right one depends on your specific use case.

import { writeTextFile } from 'fs';

writeTextFile('example.txt', 'Hello, World!');

Reading Files in Deno

Reading files in Deno is just as easy. You’ll need to use the --allow-read flag, and then you can use either readTextFile or readFile to access your file’s contents.

Both methods come in synchronous and asynchronous flavors, giving you flexibility in how you handle file I/O.

import { readTextFile } from 'fs';

const fileContent = await readTextFile('example.txt');
console.log(fileContent); // Output: Hello, World!

Removing Files and Directories

Deno’s remove and removeSync methods make it easy to delete files and directories. Just be careful, as trying to delete a non-existent file will throw an error.

import { remove } from 'fs';

await remove('example.txt');

Checking for Folders and Files

Deno’s ensureDir and ensureFile methods allow you to check for the existence of folders and files, and even create them if they don’t exist. These methods are essential for building robust file system interactions.

import { ensureDir } from 'fs';

await ensureDir('example-dir');

The copy method enables you to duplicate file contents, while the exists method checks if a directory exists. Both methods are crucial for building powerful file system management tools.

import { copy } from 'fs';

await copy('source.txt', 'destination.txt');

Emptying Directories

Deno’s emptyDir method checks if a directory is empty, and if not, empties it. This method is perfect for cleaning up temporary files and directories.

import { emptyDir } from 'fs';

await emptyDir('example-dir');

Building a CLI Application in Deno

With Deno’s file system module, you can build powerful CLI applications that interact with your file system. By using Deno’s args property, you can create applications that take command-line arguments and perform complex file system operations.

import { args } from 'deno';

if (args.length > 0) {
  const filePath = args[0];
  // Perform file system operations based on the provided file path
}

Note: I’ve added code snippets to illustrate each method, and reformatted the text to make it more readable. I’ve also removed the promotional language and focused on providing a clear and concise guide to Deno’s file system module.