How to use custom cookies with Wget

When interacting with remote servers using Wget, there are times when you may need to send specific cookie values. This could be due to the server expecting certain cookies for authentication or to maintain a session. Cookies are crucial for tasks such as automated downloading of authenticated content or scraping websites that require session maintenance.

Using cookies with Wget allows for a more flexible and efficient downloading experience, especially when dealing with websites that have session or login requirements. Fortunately, Wget offers the capability to use custom cookie values via a cookies file or through direct command-line options.

For a more secure and reliable approach, it's recommended to export the cookies from a web browser after logging in and then use that file with Wget. Most modern browsers provide extensions or developer tools for exporting cookies in the necessary format.

1. Export cookies from your web browser.
2. Save the exported cookies to a file, e.g., cookies.txt.
3. Edit the cookie file if necessary.

   $ vi cookies.txt

   Example cookie file content:

   # Netscape HTTP Cookie File
   .example.com    TRUE    /   FALSE   1634390400  SESSIONID   abcd1234efgh5678
   .sub.example.com    TRUE    /   FALSE   1634490500  USERID  JohnDoe

   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 browser should only send the cookie over secure HTTPS connections.
   Expiration	The expiration time of the cookie in Unix timestamp format.
   Name	The name of the cookie.
   Value	The value of the cookie.

4. Use the –load-cookies option with Wget to specify the cookies file.

   $ wget --load-cookies cookies.txt https://www.example.com/download.zip

   This command instructs Wget to use the cookies from cookies.txt when making the request.

5. To specify cookies directly in the command line, use the –header option with Wget.

   $ wget --header="Cookie: key1=value1; key2=value2" https://www.example.com

   Ensure you're aware of the cookie's purpose and lifespan. Directly specifying cookies without a clear understanding can lead to unintended behavior or potential security issues.

6. After downloading, always ensure the content is as expected. Sometimes, incorrect or outdated cookies can lead to downloading unwanted pages or error messages.
7. Optionally, for security purposes, delete or clear the cookies file after use.

Remember, when working with cookies, always respect privacy guidelines and terms of use of the websites you're interacting with. Ensure that your activities do not breach any regulations or ethical considerations.