Gentoo Notes

find all version of package X installed:

nex ~ # /usr/bin/equery list db
[ Searching for package 'db' in all categories among: ]
 * installed packages
[I--] [M ] dev-libs/dbus-glib-0.76 (0)
[I--] [  ] dev-libs/eggdbus-0.6 (1)
[I--] [M ] games-util/loki_setupdb-20050109 (0)
[I--] [  ] media-libs/libcddb-1.3.2 (0)
[I--] [  ] sys-apps/dbus-1.2.24 (0)
[I--] [  ] sys-apps/sandbox-1.6-r2 (0)
[I--] [  ] sys-libs/db-4.7.25_p4 (4.7)
[I--] [  ] sys-libs/db-4.8.30 (4.8)
[I--] [  ] sys-libs/gdbm-1.8.3-r3 (0)
[I--] [  ] sys-libs/pwdb-0.62 (0)
[I--] [  ] sys-libs/tdb-1.2.1 (0)
[I--] [  ] x11-apps/xcmsdb-1.0.2 (0)
[I--] [  ] x11-apps/xrdb-1.0.6 (0)
[I--] [  ] x11-libs/qt-dbus-4.6.2 (4)
nex ~ # 

What packages need package X:

nex ~ # equery d sys-libs/db-4.7.25_p4
[ Searching for packages depending on sys-libs/db-4.7.25_p4... ]
dev-lang/perl-5.8.8-r8 (berkdb? sys-libs/db)
dev-lang/python-2.6.4-r1 (!build & berkdb? sys-libs/db:4.7)
dev-libs/apr-util-1.3.9 (berkdb? >=sys-libs/db-4)
dev-vcs/subversion-1.6.9 (berkdb? =sys-libs/db-4*)
sys-apps/iproute2-2.6.31 (!minimal & berkdb? sys-libs/db)
sys-devel/libperl-5.8.8-r2 (berkdb? sys-libs/db)
sys-libs/gdbm-1.8.3-r3 (berkdb? sys-libs/db)
nex ~ #