On linix, you can find more details about a process by looking into process file system.

For example, if you need to know more about a process with process id 500, you have to go to folder /proc/500 you will find several files, which provide information about the process.

On FreeBSD process file system is not mounted by default for security reasons. You can mount it temporarily while you investigate something.

# mount -t procfs procfs /proc
# cd /proc
# cd 500
# cat cmdline

Some other command that provide information about running process are

# ps -auxwww
# lsof