How do I copy cookies from Chrome?

I am using bash to POST to a website that requires that I be logged in first, so I need to send the request with my login cookie. I tried logging in and keeping the cookies, but it doesn't work because the site uses javascript to hash the password in a really weird fashion, so instead I'm going to just take my login cookies for the site from Chrome. How do get the cookies from Chrome and format them for Curl?

I'm trying to do this:

curl --request POST -d "a=X&b=Y" -b "what goes here?" "site.com/a.php"

Solution

Hit F12 to open the developer console (Mac: Cmd+Opt+J)
Look at the Network tab.
Do whatever you need to on the web site to trigger the action you're interested in
Right click the relevant request, and select "Copy as cURL"

This will give you the curl command for the action you triggered, fully populated with cookies and all. You can of course also copy the flags as a basis for new curl commands.