web-server-index-page-downloader.js

// Direcory Listing Downloader - "Index Of/" Downloader
// Moe Khalil - me@mkhalil.org 
// This is to download files located in directories with directory list permissions enabled
// set MINIMUM_SIZE to filter smaller files.
// File names will be what they are on server with date prepended and host domain appended.

(() => {
  // minimum file-size to download
  const MINIMUM_SIZE = '800K';

  const bytesLUT = { K: 10**3, M: 10**6, G: 10**9, T: 10**12 };
  const toBytes = x => parseInt(x.match(/[0-9.]*/)[0], 10) * bytesLUT[x.substr(-1)];
  const minimumBytes = toBytes(MINIMUM_SIZE);

  // filename-prefix: en-CA => 12-31-2020. this => 12.31.2020
  const prefix = new Date().toLocaleDateString('en-CA').replace(/-/g, '.');
  const suffix = `[${window.location.host}]`;
  
  // filename
  const namer = (x) => {
    const ogName = x.href.split(/\//).pop();
    const [name, extension] = [ogName.slice(0, ogName.lastIndexOf('.')), ogName.slice(ogName.lastIndexOf('.'))];
    return `${prefix}-${name}-${suffix}${extension}`;
  }

  // to download based on size in table and MINIMUM_SIZE
  // the seemingly FRAGILE Dom navigation navigates to the size column of the table
  const toDownload = (x) => {
    const fileSize = x.parentElement.nextSibling.nextSibling.textContent;
    const fileSizeInBytes = toBytes(fileSize);    
    return toBytes(fileSize) >= minimumBytes;
  };

  const downloader = (file, k) => {
    if (!toDownload(file)) { return; }
    file.download = namer(file); 
    globalThis.setTimeout(() => file.click(), k * 100); 
  } 

  document.querySelectorAll('table td a').forEach(downloader);
  
  // For non-standard "/index of" pages
  // Make sure the next sibling of the anchor tag includes file size.
  /*
  const FILTER = "filename-includes-this";

   Array.from(
     document.querySelectorAll('a')
   ).filter(i => 
     i.text.toLowerCase().includes(FILTER) &&
     i.nextSibling.textContent.match('[0-9]*k') >= MINIMUM_SIZE
   ).forEach((file, k) => {    
     file.download = namer(file); 
     globalThis.setTimeout(() => file.click(), k * 100); 
   }); 
   */
  
})();