How to save session cookies in Wget

When accessing authenticated or session-based HTTP resources, cookies play a crucial role. These small data fragments let servers maintain client state across multiple requests. wget can handle cookies, making it possible to reuse session information during scripted downloads.

By saving cookies from one request and using them in subsequent requests, wget preserves the session context. This is important for tasks like retrieving pages behind login screens or accessing user-specific data without repeatedly authenticating.

Proper management of these cookies enhances automation and efficiency. It also demands caution, as cookies may contain sensitive session details. Protecting and discarding them when no longer needed is an essential security measure.

1. Start a session and save cookies to a file with the --save-cookies option.

   $ wget --save-cookies cookies.txt --keep-session-cookies -O /dev/null https://www.example.com/login

   --keep-session-cookies retains session-only cookies that would otherwise be discarded.

2. Inspect the cookie file to verify the stored cookies.

   $ cat cookies.txt

   The file uses the Netscape cookie format, listing domain, path, expiration, name, and value.

   Field	Description
   Domain	The domain of the cookie. Usually set to the domain of the website.
   Flag	A boolean field (TRUE/FALSE) indicating if all machines within a given domain can access the cookie.
   Path	The path to which the cookie is available.
   Secure	A boolean field (TRUE/FALSE) indicating if the cookie is only sent over HTTPS.
   Expiration	The expiration time of the cookie in Unix timestamp format.
   Name	The name of the cookie.
   Value	The value of the cookie.

3. Edit the cookie file if necessary, ensuring format integrity.

   $ nano cookies.txt

   Adjusting cookie values may be needed for testing or troubleshooting.

4. Use the saved cookies in subsequent requests with --load-cookies.

   $ wget --load-cookies cookies.txt https://www.example.com/dashboard -O dashboard.html

   This request includes previously saved cookies, maintaining the session.

5. Check the downloaded page to confirm the session was retained.

   $ cat dashboard.html

   Verify that the content matches what is expected for an authenticated session.

6. Secure the cookie file by restricting file permissions.

   $ chmod 600 cookies.txt

   Protect cookie files to prevent unauthorized access to session data.

7. Remove the cookie file when it is no longer needed.

   $ rm cookies.txt

   Deleting cookies ensures sensitive session data is not retained indefinitely.