Node.js filehandle.readFile() Method
The filehandle.readFile() method is used to asynchronously read the file contents. This method reads the entire file into the buffer. It Asynchronously reads the entire contents of a file.
Syntax:
filehandle.readFile( options )
Parameters: The method accepts single parameter as mentioned above and described below:
- options: It holds the encoding of file. Its default value is ‘utf8’. It is an object or a string.
- encoding: It is a String or NULL. Default: null
Return Value: It returns a Promise.
- The Promise is resolved with the contents of the file. If no encoding is specified using options.encoding, the data is returned as a Buffer object. Otherwise, the data will be a string.
- If options is a string, then it specifies the encoding.
- The FileHandle has to support reading.
Example: Read the file contents of the file ‘GFG.txt’
Note: ‘GFG.txt’ should be present in the directory with the following text:
w3wiki - A computer science portal for Beginner
Filename: app.js
// Node.js program to demonstrate the // fsPromises.truncate() Method // Import the filesystem module const fs = require('fs'); const fsPromises = fs.promises; // Using the async function to // ReadFile using filehandle async function doReadFile() { let filehandle = null; try { // Using the filehandle method filehandle = await fsPromises.open('GFG.txt', 'r+'); var data = await filehandle.readFile("utf8"); console.log(data); } catch (e) { console.log("Error", e); } } doReadFile().catch((error) => { console.log("Error", error) }); |
Run app.js file using the following command:
node app.js
Output:
w3wiki - A computer science portal for Beginner
Reference: https://nodejs.org/dist/latest-v14.x/docs/api/fs.html#fs_filehandle_readfile_options