Chrome可访问的TIF文件无法用wget下载，报401未授权

Hey there! Let's figure out why Chrome can download those TIF files without login issues, but wget is throwing a 401 error. The key here is that browsers send extra headers and sometimes session cookies that the server expects—wget doesn't do this by default. Here's how to fix it:

1. Capture Chrome's Request Details #

First, let's see exactly what Chrome sends to the server when it downloads the file. This will give us the headers/cookies we need to replicate in wget:

• Open Chrome and navigate to your TIF file URL.
• Press F12 to open DevTools, then switch to the Network tab.
• Find the entry for your TIF file (it should be near the top), right-click it, and select Copy > Copy as cURL (bash).

2. Convert cURL Command to Wget #

The copied cURL command includes all the headers and cookies Chrome used. We can translate this to wget parameters:

• Extract the User-Agent, Accept, and Cookie headers from the cURL command.
• Use wget's --header flag to add each one. Here's an example (replace the placeholder values with what you copied):

  wget --no-check-certificate \
    --header="User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/118.0.0.0 Safari/537.36" \
    --header="Accept: image/webp,image/apng,image/svg+xml,image/*,*/*;q=0.8" \
    --header="Cookie: paste_your_cookie_string_here" \
    https://ulib.aub.edu.lb/nahar/images2/7810W2/78101001.TIF
  

3. Test Simplified Versions First #

You might not need all headers—start with the simplest fix to save time:

• Try just the User-Agent first: Some servers block requests with non-browser User-Agents (wget uses a default one like Wget/1.21.3). Run this:

  wget --no-check-certificate --user-agent="Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/118.0.0.0 Safari/537.36" https://ulib.aub.edu.lb/nahar/images2/7810W2/78101001.TIF
  

• If that fails, add the Cookie header from your cURL copy. The server might be setting a session cookie even without login (for tracking or access control).

4. Alternative: Use cURL Directly #

If converting to wget feels tricky, you can use the copied cURL command directly (just add -O to save the file with its original name):

curl --insecure -O https://ulib.aub.edu.lb/nahar/images2/7810W2/78101001.TIF \
  -H "User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/118.0.0.0 Safari/537.36" \
  -H "Accept: image/webp,image/apng,image/svg+xml,image/*,*/*;q=0.8" \
  -H "Cookie: paste_your_cookie_string_here"

(--insecure does the same as wget's --no-check-certificate to bypass SSL certificate checks.)

Let me know if any of these steps work for you—happy to help tweak things further if needed!

内容的提问来源于stack exchange，提问作者Abuflaan