file descriptor question

[pahud]

I am sorry if this is off-topic here.

Is there any way to find out the file descriptor number of a specific account currently in use? Well, I can use ulimit -n to check the
max number of fd, but how to check the number of the total fd currently in use?

Question 2. When I use ssh to login my Gentoo box then I type
"ulimit -n", it does not accommodate to the limit control in /etc/security/limits.conf, but I am sure I have this line