CODEWITHSUNDEEP
node.js
AGamePlayer
AGamePlayer

Reputation: 7736

how to use NodeJS to modify a file and save to a new one?

I have a plain text file named source.txt

I want to use a NodeJS script to do something to modify the content of the txt file and save as a new file, say output.txt

How do I do that?

I am expecting a command-line implementation, something like:

$node modify.js source.txt output.txt

Thanks!

Upvotes: 2

Views: 8656

Answers (2)

damphat
damphat

Reputation: 18956

Sync style:

// save as: uppercase.js

var fs = require('fs');

var input = process.argv[2];
var output = process.argv[3];

var content = fs.readFileSync(input, 'utf8');
content = content.toUpperCase();    
fs.writeFileSync(output, content);

Run:

$node uppercase source.txt output.txt

Upvotes: 4

brandonscript
brandonscript

Reputation: 72845

Use Node.js's build in fs() function to read and write files to the local filesystem.

Basic read example:

fs.readFile('source.txt', function (err, data) {
    if (err) throw err;
    console.log(data);
});

Basic write example:

fs.writeFile('output.txt', 'Hello Node', function (err) {
    if (err) throw err;
    console.log('It\'s saved!');
});

Note: ensure your Node instance (and the account it's being run under) has appropriate permissions to the read and write source/destination.

Upvotes: 2

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