CURL: How retain cookies between requests?

Question

I need to login to a page and then submit an entry. i'm able to login with the following code

curl $HOST -s -L -b $COOKIE -c $COOKIE -d "login=submit&login_name=$USER&login_password=$PASS" -o $OUTPUT

but when i try to submit an entry i'm not logged in anymore

curl $HOSTADDNEWS -L -b $COOKIE -c $COOKIE -A $HEADER -d "title=$TITLE" -o $OUTPUT.add.news

How to retain cookies between requests?

Answer 1

Thanks to Daniel Stenberg! $COOKIE variable had a "slash" in it... it still saved to file but wasn't able to use it.