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Synchronous and Asynchronous File Delete, Read, Write, Append in NodeJS

Synchronous and Asynchronous File Delete in NodeJS

Synchronous Delete File



const fs = require('fs');



// Unlink is synchronous while unlinkSync is asynchronous.



// Unlink returns error or nothing. If nothing then task is successful. If error, task is unsuccessful.



fs.unlink('./test5.txt', err => {



    if (err) {



        console.log(err);



    } else {



        console.log("Done synchronously.");



    }



});



console.log("Independent line");
Asynchronous Delete File



const fs = require('fs');



try {



    fs.unlinkSync('./test5.txt');



} catch (err) {



    console.log(err);



} finally {



    console.log("Done operation!");



}



console.log("Independent line");

Synchronous and Asynchronous File Read in NodeJS

Synchronous Read File



const fs = require('fs');



fs.readFile('./testfile.txt', "utf8", (err, data) => {



    if (err) {



        console.log.apply(err);



    } else {



        console.log(data);



    }



});



console.log("independent line");
Asynchronous Read File



const fs = require('fs');



try {



    const content = fs.readFileSync('./testfile.txt', { encoding: "utf8" });



} catch (err) {



    console.log(err);



} finally {



    console.log("Done operation!");



}



console.log("Independent line");

Synchronous and Asynchronous File Write in NodeJS

Synchronous Write File



const fs = require('fs');



fs.writeFile('./testfile.txt', "Content", err => {



    if (err) {



        console.log(err);



    } else {



        console.log("Successful writing!");



    }



});



console.log("independent line");
Asynchronous Read File



const fs = require('fs');



try {



    fs.writeFileSync('./testfile.txt', "Async Content");



} catch (err) {



    console.log(err);



} finally {



    console.log("Done operation!")



}



console.log("independent line");

Synchronous and Asynchronous File Append in NodeJS

Synchronous Append File



const fs = require('fs');



fs.appendFile('./testfile.txt', "Content", err => {



    if (err) {



        console.log(err);



    } else {



        console.log("Successful updating!");



    }



});



console.log("independent line");
Asynchronous Append File



const fs = require('fs');



try {



    fs.appendFileSync('./testfile.txt', "Append Async Content");



} catch (err) {



    console.log(err);



} finally {



    console.log('Done Operation!')



}



console.log("independent line");
That's it!

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