When you don't know the full name of a command or file, but need to find it, you can usually find it with locate. locate uses a database to find all files on your system. Normally, this database gets built from a cron job every night. This won't happen, however, if your machine isn't booted into Linux all the time. So, if that is the case, you may occasionally want to run the following command:
/usr/bin/updatedb --prunepaths='/tmp /proc /mnt /var/tmp /dev'
You will need to be root on your system when doing that. That will allow locate to work properly.
So, if you know you need to find all the ``finger'' files, you could run:
locate finger
It should return something like:
/usr/bin/finger /usr/lib/irc/script/finger /usr/man/man1/finger.1 /usr/man/man8/in.fingerd.8 /usr/sbin/in.fingerd
One thing to note, however, is that locate not only returns hits based on file name, but also on path name. So if you have a /home/djb/finger/ directory on your system, it would get returned along with all files in the directory.