how to use the appendfile function from fs-extra in javascript

To use the appendFile function from the fs-extra module in Node.js, you need to follow these steps:

1. Install the fs-extra module by running the following command in your project directory:

npm install fs-extra
21 chars
2 lines

2. Require the fs-extra module in your JavaScript file as follows:

index.tsx
const fs = require('fs-extra');
32 chars
2 lines

3. Use the appendFile function to append data to a file. The syntax for the appendFile function is as follows:

index.tsx
fs.appendFile(file, data, [options], [callback])
49 chars
2 lines

Here is an example:

index.tsx
fs.appendFile('message.txt', 'data to append', function (err) {
  if (err) throw err;
  console.log('Data appended to file!');
});
131 chars
5 lines

This code appends the string "data to append" to the file message.txt. If the file doesn't exist, it will be created.

You can also pass options to the appendFile function, such as the encoding to use and the file mode. Here is an example:

index.tsx
fs.appendFile('message.txt', 'data to append', { encoding: 'utf8', mode: 0o666, flag: 'a+' }, function (err) {
  if (err) throw err;
  console.log('Data appended to file!');
});
178 chars
5 lines

In this code, we are appending data to the file using "utf8" encoding, setting the file mode to "0o666" and using the "a+" flag to open the file in append mode.