I have been looking at performance for a web application. I am using ab to compare the response times while adjusting the database indexing.

# 'log in'
curl -L https://www.example.com/login.php -k -b cookie -c cookie-jar -d username=admin -d password=**** -s > /dev/null
# Run the test -n times (in this case 10)
ab -C `grep PHP_session cookie-jar | cut -f6,7 | tr '\t' '='` -n 10 'https://www.example.com/main.php'

What's happening?

The curl command is logging in to the application and saving the cookies in a file named cookie-jar.

The grep command is extracting the session id cookie - name and value - from the cookie-jar and using it to authorize access to a main page for ab.

This post courtesy of Game Creek Video