Batch File Renaming in Node from a JSON File

The Goal

So, let's say you have a few hundred ${guid}.zip or other files that uniformally match up to a data source but you need to rename them to something friendly like ${name}.zip, for example.

    02cf5525-8fa2-4af9-b93f-9ec5fa1973fe.zip => Pizza.zip

data.json

An example of how our data might look.

[
    {
        "guid": "02cf5525-8fa2-4af9-b93f-9ec5fa1973fe",
        "name": "Pizza"
    },
    {
        "guid": "33371cae-1056-43f5-837d-326b4467e423",
        "name": "Beer"
    },
    {
        "guid": "508216a5-3d7c-4918-a47a-67100e324099",
        "name": "Pretzels"
    }
]

index.js

Our script will start by reading that JSON file and then begin iterating over each key. In our case, if it doesn't find a file that matches up with the guid key in our Object it will write-out a text file with the guid it couldn't find. Pretty handy if you have a massive object, a ton of files and wanted to make sure you weren't missing anything. :)

// Require Node's File System module
const fs = require('fs');

// Read the JSON file
fs.readFile('data.json', function (error, data) {
    if (error) {
        console.log(error);
        return;
    }

    const obj = JSON.parse(data);

    // Iterate over the object
    Object.keys(obj).forEach(key => {
        let _from = `${__dirname}/files/${obj[key].guid}.zip`;
        let _to = `${__dirname}/files/${obj[key].name}.zip`;

        console.log(_from, _to); 

        fs.rename(_from, _to, function (err) {
             if (err){
                 console.log('ERROR: ' + err);

                 // If there was a file defined in the data.json that was supposed to be renamed but did not exist
                 // Let us know which files (if any) were missing
                 let stream = fs.createWriteStream(`${__dirname}/files/${obj[key].guid}.txt`);
                 stream.once('open', function (fd) {
                     stream.write("This file was supposed to be defined in the object\n");
                     stream.end();
                 });
            }
        });
    });
});

Download

Download source on GitHub

If you have any questions, hit me up on Twitter.