Type

type shows what kind of thing you're running, be it an alias, function, or binary program.

type cmus

Whereis the Program

Ask where the angband program is, along with all its configuration files:

whereis angband

Also which shows where a binary file (the program) is,

which cmus

You'll need to set up locate for this by installing mlocate. mlocate needs a list of all files on the machine, so run:

sudo updatedb

Then to find a file called 'my-cats.jpg', run:

locate cats

For best results, run updatedb regularly, perhaps in crontab.