Listing files contained in an installed package

To know the files contained in an installed package, run the following command:

Debian/Ubuntu and derivatives

$ dpkg -L cmus
/.
/ usr
/ usr/lib
/usr/lib/Cmus
/usr/lib/Cmus/op
/usr/lib/cmus/op/pulse.so
/usr/lib/cmus/op/ao.so
/usr/lib/cmus/op/oss.so
/usr/lib/cmus/op/alsa.so
...

CentOS/Fedora/RHEL

$ rpm - ql grep
/bin/egrep
/bin/fgrep
/bin/grep
/usr/share/doc/grep-2.5.1
/usr/share/doc/grep-2.5.1/ABOUT-NLS
/usr/share/doc/grep-2.5.1/AUTHORS
/usr/share/doc/grep-2.5.1/ChangeLog
/usr/share/doc/grep-2.5.1/NEWS
/usr/share/doc/grep-2.5.1/READ
...

Recommended reading

-man dpkg
-man rpm