File SystemΒΆ

NodeJS comes with an extensive file system API in a module called fs. However, the module is traditionally based on callbacks. In this book, we will be focused on writing codes using promise based APIs which can be easily used in async/await paradigm. Hence, we will use a library named fs-extra.

Checking existence of a file

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const fs = require('fs-extra');

(async () => {
    let filename = './fs.rst';
    let exists = await fs.pathExists(filename);
    if (exists){
        console.log(`The file ${filename} exists.`);
    } else {
        console.log(`The file ${filename} does not exist.`);
    }
})();

Reading a file

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const fs = require('fs-extra');

(async () => {
    // The readFile function reads the contents of a file in a buffer.
    let contents = await fs.readFile('read_file.js');
    // Buffer can be converted into string for further processing.
    let contents_str = contents.toString();
    console.log(contents_str);
})();