Posting XML through cURL using –data-binary

You can pass data into curl via STDIN like so:

echo -e '...data...\n' | curl -X POST --data-binary @- http://foo.com

The @- tells curl to pull in from STDIN.

To pipe binary data to curl (for example):

echo -e '\x03\xF1' | curl -X POST --data-binary @- http://foo.com

Well, you'll need to store the session data in a cookie. You can use -c cookie_filename to create the cookie (add this to your login command). And then, for the other requests, you can read from the cookie with -b cookie_filename.

In example:

curl -s loginpage -c cookiefile -d "user=myself&pass=secure"
curl -s secretpage -b cookiefile

EDIT:

Notice many times loginpage is not the page you open with your web browser where you introduce your user and password. You'll have to check where the form is posting that data to (search the <form> tag in the source code and the action=... attribute). So, for example, if you want to log in to https://criticker.com, loginpage is https://www.criticker.com/authenticate.php and not https://www.criticker.com/signin.php, which is the one you open with your browser.

A tampering plugin/extension for your browser may help you find the correct loginpage and all the data that is being posted to it (like hidden input fields in the form).