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Simple URL Unshortener

Unshortens URLs by following redirect chains (console only)

  1. // ==UserScript==
  2. // @name         Simple URL Unshortener
  3. // @namespace    http://tampermonkey.net/
  4. // @version      1.0
  5. // @description  Unshortens URLs by following redirect chains (console only)
  6. // @author       maanimis
  7. // @match        *://*/*
  8. // @grant        GM_registerMenuCommand
  9. // @grant        GM_xmlhttpRequest
  10. // @license      MIT
  11. // ==/UserScript==
  12.  
  13. (function() {
  14.     'use strict';
  15.  
  16.     // Register the menu command
  17.     GM_registerMenuCommand("Unshorten URL", startUrlUnshortener);
  18.  
  19.     function startUrlUnshortener() {
  20.         // Ask user for the shortened URL
  21.         const shortUrl = prompt("Enter the shortened URL to unshorten:");
  22.  
  23.         if (!shortUrl) {
  24.             console.log("No URL entered. Operation cancelled.");
  25.             return;
  26.         }
  27.  
  28.         // Validate URL format
  29.         try {
  30.             new URL(shortUrl);
  31.         } catch (e) {
  32.             console.log("Invalid URL format. Please enter a valid URL.");
  33.             return;
  34.         }
  35.  
  36.         // Start the unshortening process
  37.         console.log("Starting URL unshortening process...");
  38.         console.log("Initial URL:", shortUrl);
  39.  
  40.         const redirectChain = [shortUrl];
  41.         followRedirect(shortUrl, redirectChain, 0);
  42.     }
  43.  
  44.     function followRedirect(url, redirectChain, step) {
  45.         // Maximum of 3 redirects
  46.         if (step >= 3) {
  47.             console.log("Reached maximum redirect depth (3)");
  48.             displayResults(redirectChain);
  49.             return;
  50.         }
  51.  
  52.         console.log(`Following step ${step+1}: ${url}`);
  53.  
  54.         GM_xmlhttpRequest({
  55.             method: "HEAD",
  56.             url: url,
  57.             headers: {
  58.                 "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36"
  59.             },
  60.             timeout: 10000, // 10 second timeout
  61.             anonymous: true, // Don't send cookies
  62.             fetch: true, // Use fetch mode if available
  63.             onload: function(response) {
  64.                 console.log(`Received response for ${url} with status: ${response.status}`);
  65.  
  66.                 // Check if we have a redirect status code
  67.                 if (response.status >= 300 && response.status < 400) {
  68.                     let nextUrl = null;
  69.  
  70.                     // Try to get location from response headers
  71.                     if (response.responseHeaders) {
  72.                         const locationMatch = response.responseHeaders.match(/location:\s*(.*?)(?:\r?\n|$)/i);
  73.                         if (locationMatch && locationMatch[1]) {
  74.                             nextUrl = locationMatch[1].trim();
  75.                         }
  76.                     }
  77.  
  78.                     // If we still don't have a nextUrl, try finalUrl
  79.                     if (!nextUrl && response.finalUrl && response.finalUrl !== url) {
  80.                         nextUrl = response.finalUrl;
  81.                     }
  82.  
  83.                     // Process relative URLs if needed
  84.                     if (nextUrl && !nextUrl.match(/^https?:\/\//i)) {
  85.                         try {
  86.                             const urlObj = new URL(url);
  87.                             if (nextUrl.startsWith('/')) {
  88.                                 nextUrl = `${urlObj.protocol}//${urlObj.host}${nextUrl}`;
  89.                             } else {
  90.                                 const path = urlObj.pathname.substring(0, urlObj.pathname.lastIndexOf('/') + 1);
  91.                                 nextUrl = `${urlObj.protocol}//${urlObj.host}${path}${nextUrl}`;
  92.                             }
  93.                         } catch (e) {
  94.                             console.error("Error processing relative URL:", e);
  95.                         }
  96.                     }
  97.  
  98.                     if (nextUrl && nextUrl !== url) {
  99.                         console.log(`Redirect found: ${nextUrl}`);
  100.                         redirectChain.push(nextUrl);
  101.                         followRedirect(nextUrl, redirectChain, step + 1);
  102.                     } else {
  103.                         console.log("No valid redirect found or redirect to same URL.");
  104.                         displayResults(redirectChain);
  105.                     }
  106.                 } else {
  107.                     // No redirect, we've reached the final URL
  108.                     console.log(`Final URL reached: ${url}`);
  109.                     displayResults(redirectChain);
  110.                 }
  111.             },
  112.             onerror: function(error) {
  113.                 console.error(`Error following redirect for ${url}:`, error);
  114.                 displayResults(redirectChain);
  115.             },
  116.             ontimeout: function() {
  117.                 console.error(`Request timed out for ${url}`);
  118.                 displayResults(redirectChain);
  119.             }
  120.         });
  121.     }
  122.  
  123.     function displayResults(redirectChain) {
  124.         console.log("\n===== URL UNSHORTENING RESULTS =====");
  125.         console.log("Complete redirect chain:");
  126.  
  127.         redirectChain.forEach((url, index) => {
  128.             console.log(`${index + 1}. ${url}`);
  129.         });
  130.  
  131.         console.log(`\nTotal URLs in chain: ${redirectChain.length}`);
  132.         console.log("======================================\n");
  133.     }
  134. })();
  135.