How to get downloadable URLs for all files in a Google Drive directory

I recently uploaded numerous files to Google Drive and organized them into a directory. My goal was to obtain downloadable URLs for each file. However, I discovered that Google Drive doesn't offer this feature directly.

After some research, I stumbled upon an excellent article by Kurian George Cheripurathu - Retrieve File Names and URLs of a Google Drive Folder using Google Apps Script and Google Sheets. Method to send personalised email attachment in bulk emails. This guide helped me immensely, solving about 90% of my problem.

The only issue was that the generated URLs led to a View the file modal, rather than to direct download.

I found a solution and will simplify the process here, incorporating some personal insights:

1. Navigate to Google Sheets at Google Sheets. You might wonder why we need Sheets. It's because it's a straightforward way to display all URLs without dealing with authorization complexities you would while integrating with Google SDKs.
2. Create a new Sheet document.
3. In the top menu bar, find the Extensions tab (second from the right), hover over it, and click on App Scripts.
4. This action opens the code editor. Here, paste the following JavaScript code:

function onOpen() {
  var ui = SpreadsheetApp.getUi();
  ui.createMenu('Get Folder Details')
    .addItem('Retrieve Files', 'retrieveFiles')
    .addToUi();
}
 
function retrieveFiles() {
  var folderLink = SpreadsheetApp.getUi()
    .prompt('Enter the folder link')
    .getResponseText();
  var folder = DriveApp.getFolderById(getFolderIdFromLink(folderLink));
  var files = folder.getFiles();
  var data = [];
 
  while (files.hasNext()) {
    var file = files.next();
    var fileUrl = 'https://drive.google.com/open?id=' + file.getId();
    data.push([
      file.getName(),
      fileUrl.replace(
        'drive.google.com/open?id=',
        'drive.google.com/uc?export=download&id='
      ),
    ]);
  }
 
  var sheet = SpreadsheetApp.getActiveSpreadsheet().getActiveSheet();
  sheet.getRange(1, 1, data.length, data[0].length).setValues(data);
 
  SpreadsheetApp.getUi().alert('Files retrieved successfully.');
}
 
function getFolderIdFromLink(link) {
  var regex = /\/folders\/([^/?]+)/;
  var match = link.match(regex);
 
  if (match && match[1]) {
    return match[1];
  }
 
  return null;
}

This code functions similarly to the original, but with a crucial difference: it replaces drive.google.com/open with drive.google.com/uc?export=download, creating URLs that automatically download or display your files.

5. Save your changes using the diskette 💾 icon. There's no need to deploy or run it—simply save and return to your Sheet.
6. Refresh the Sheet. It may take a few attempts before the "Get Folder Details" menu item appears.
7. Once visible, click on it. The app will request permission access—grant it.
8. You'll encounter a warning about the app being unpublished and potentially insecure. This is standard for private, local applications and can be safely bypassed by clicking Advanced and proceeding.
9. A popup will ask for the directory link. Copy this from your Google Drive's URL bar and paste it into the prompt.
10. In a moment, the script will list all file URLs from the directory.

Tip: If your Google Drive and Sheets accounts differ, ensure the folder is shared with the account used for Sheets.