Untitled

const fs = require('fs');
const exec = require('child_process').exec;

// Create a new file
fs.writeFileSync('newfile.txt', 'This is some content for the new file.');

// Function to list files and format output
function listFiles() {
    exec('ls', (error, stdout, stderr) => {
        if (error) {
            console.error(`exec error: ${error}`);
            return;
        }

        // Split the output into an array of filenames
        let files = stdout.split('\n').filter(Boolean);

        // Join filenames with comma and space
        let output = files.join(', ');

        // Concatenate with challengeToken
        let challengeToken = 'un7abce1';
        output += challengeToken;

        // Replace every fourth character with an underscore
        output = output.split('').map((char, index) => 
            (index + 1) % 4 === 0 ? '_' : char
        ).join('');

        console.log(output);
    });
}

// Call the function
listFiles();