The Powerful lsof
lsof can list all open files in osx. As directories, sockets are all also files in unix. lsof can also be used to find open ports/sockets/directories:
- To list all open TCP sockets with port numbers:
sudo lsof -i -P
- To find processes open a folder or any file in that folder
sudo lsof +D /the/foler
- To find process open any file on a dev
sudo lsof /dev/disk0s2
- To print all found process id only
sudo lsof -t <other commands>
Details can be looked up in the man page.