Listing open files by a process will help in debugging any process.
To list open files and configurations used by any process ID we can use lsof command.
To view open files and configurations used by process ID 12345 use following command:
$ lsof -p 12345
This will list all files used by process ID.
We can use lsof with process name also.
To view list of open files for firefox use following command:
$ lsof -p `pidof firefox`
Similarly we can use above command for other processes.