# emerge gentoolkit

# equery belongs /usr/bin/xmms
[ Searching for file(s) /usr/bin/xmms in *... ]
media-sound/xmms-1.2.10-r9 (/usr/bin/xmms)

# equery check gentoolkit
[ Checking app-portage/gentoolkit-0.2.0 ]
 * 54 out of 54 files good

# equery depends pygtk
[ Searching for packages depending on pygtk... ]
app-office/dia-0.93
dev-python/gnome-python-2.0.0-r1
gnome-extra/gdesklets-core-0.26.2
media-gfx/gimp-2.0.4
x11-libs/vte-0.11.11-r1

# equery depgraph cdrtools
Displaying dependencies for app-cdr/cdrtools-2.01_alpha37
`-- app-cdr/cdrtools-2.01_alpha37
 `-- sys-libs/glibc-2.3.4.20040808 (virtual/libc)
  `-- sys-kernel/linux-headers-2.4.22 (virtual/os-headers)
   `-- sys-apps/baselayout-1.10.4
    `-- sys-apps/sysvinit-2.85-r1
     `-- sys-apps/gawk-3.1.3-r1
      `-- sys-apps/util-linux-2.12-r4
          `-- sys-apps/sed-4.0.9
	      `-- sys-libs/ncurses-5.4-r4
	          `-- sys-apps/pam-login-3.14
	          `-- sys-libs/pam-0.77-r1
                 `-- sys-libs/cracklib-2.7-r10
               `-- sys-apps/miscfiles-1.3-r1
              `-- app-arch/gzip-1.3.5-r1
              `-- sys-apps/portage-2.0.50-r10

# equery files gentoolkit
[ Searching for packages matching gentoolkit... ]
app-portage/gentoolkit-0.2.0
* Contents of app-portage/gentoolkit-0.2.0:
/usr
/usr/bin
/usr/bin/equery
/usr/bin/etcat
/usr/bin/euse
/usr/bin/glsa-check
/usr/bin/qpkg
/usr/bin/revdep-rebuild
/usr/lib
/usr/lib/gentoolkit
/usr/lib/gentoolkit/pym
/usr/lib/gentoolkit/pym/gentoolkit
/usr/lib/gentoolkit/pym/gentoolkit/__init__.py
/usr/lib/gentoolkit/pym/gentoolkit/gentoolkit.py
/usr/lib/gentoolkit/pym/gentoolkit/pprinter.py
/usr/lib/gentoolkit/pym/glsa.py
/usr/sbin
/usr/share
/usr/share/doc
/usr/share/doc/gentoolkit-0.2.0_pre10

[...]

# equery hasuse mozilla
[ Searching for USE flag mozilla in all categories among: ]
 * installed packages
[I--] [  ] dev-java/blackdown-jre-1.4.2.01 (1.4.2)
[I--] [  ] mail-client/evolution-2.0.2 (2.0)

# equery list gentoolkit
[ Searching for package 'gentoolkit' in all categories among: ]
 * installed packages
[I--] [  ] app-portage/gentoolkit-0.2.0 (0)

# equery list -p -o vim
[ Searching for package 'vim' in all categories among: ]
 * installed packages
[I--] [  ] app-editors/vim-6.3-r4 (0)
 * Portage tree (/usr/portage)
[-P-] [M~] app-editors/vim-7.0_alpha20050126 (0)
[-P-] [M~] app-editors/vim-7.0_alpha20050201 (0)
[-P-] [  ] app-editors/vim-6.3-r2 (0)
[-P-] [M~] app-editors/vim-7.0_alpha20050122 (0)
[-P-] [M~] app-editors/vim-core-7.0_alpha20050126 (0)
[-P-] [  ] app-editors/vim-core-6.3-r3 (0)
[-P-] [M~] app-editors/vim-core-7.0_alpha20050122 (0)
[-P-] [M~] app-editors/vim-core-7.0_alpha20050201 (0)
[-P-] [  ] app-editors/vim-core-6.3-r4 (0)
 * overlay tree (/opt/ebuilds)

# equery size openoffice-bin
* app-office/openoffice-bin-1.1.2
	   Total Files : 2908
	   Total Size  : 223353.31 KiB

# equery uses ethereal
[ Colour Code : set unset ]
[ Legend    : (U) Col 1 - Current USE flags        ]
[           : (I) Col 2 - Installed With USE flags ]

 U I [ Found these USE variables in : net-analyzer/ethereal-0.10.6 ]
 - - adns  : Adds support for the adns DNS client library
 + + gtk   : Adds support for x11-libs/gtk+ (The GIMP Toolkit)
 - - ipv6  : Adds support for IP version 6
 - - snmp  : Adds support for the Simple Network Management Protocol if available
 + + ssl   : Adds support for Secure Socket Layer connections
 + + gtk2  : Use gtk+-2.0.0 over gtk+-1.2 in cases where a program supports both.
 - - debug : Tells configure and the makefiles to build for debugging. Effects vary  across packages,
             but generally it will at least add -g to CFLAGS. Remember to set  FEATURES=nostrip too

# equery which cdrtools
/usr/portage/app-cdr/cdrtools/cdrtools-2.01_alpha37.ebuild

#  euse -a 
X                   [+ CD ]
aalib               [+    ]
acpi                [+ C  ]
alsa                [+ C  ]
apache2             [+ C  ]
apm                 [+  D ]
avi                 [+  D ]
berkdb              [+  D ]
bitmap-fonts        [+  D ]
bonobo              [+    ]
cdr                 [+ C  ]
crypt               [+ CD ]
cscope              [+ C  ]
cups                [+ CD ]
curl                [+    ]
emboss              [+  D ]
encode              [+  D ]
esd                 [+    ]
ethereal            [+ C  ]
fam                 [+    ]
fbcon               [+ C  ]
font-server         [+  D ]
foomaticdb          [+  D ]
fortran             [+  D ]
gd                  [+ C  ]
gdbm                [+  D ]
gif                 [+ CD ]
gimpprint           [+ C  ]
gnome               [+ CD ]
gphoto2             [+    ]
gpm                 [+ CD ]
gstreamer           [+ C  ]
gtk                 [+  D ]
gtk2                [+ CD ]
gtkhtml             [+ C  ]
guile               [+    ]
imagemagick         [+    ]
imlib               [+ CD ]
imlib2              [+    ]
innodb              [+    ]
ipv6                [+  D ]
javascript          [+ C  ]
jpeg                [+ CD ]
kde                 [+  D ]
ldap                [+    ]
libg++              [+ CD ]
libwww              [+ CD ]
mad                 [+ CD ]
mbox                [+ C  ]
md5sum              [+ C  ]
mikmod              [+ CD ]
mmx                 [+ C  ]
motif               [+ CD  ]
mozilla             [+ C  ]
mp3                 [+    ]
mpeg                [+ CD ]
mpeg4               [+ C  ]
mysql               [+ C  ]
ncurses             [+ CD ]
nls                 [+  D ]
nvidia              [+ C  ]
odbc                [+    ]
offensive           [+    ]
oggvorbis           [+ CD ]
opengl              [+ CD ]
oss                 [+  D ]
pam                 [+ CD ]
pdflib              [+ CD ]
perl                [+ CD ]
png                 [+ CD ]
python              [+ CD ]
qt                  [+  D ]
quicktime           [+ CD ]
readline            [+ CD ]
ruby                [+    ]
sdl                 [+ CD ]
slang               [+  D ]
spell               [+ CD ]
sse                 [+ C  ]
ssl                 [+ CD ]
svga                [+ CD ]
tcltk               [+ C  ]
tcpd                [+  D ]
tiff                [+ C  ]
truetype            [+ CD ]
truetype-fonts      [+  D ]
type1-fonts         [+  D ]
usb                 [+ C  ]
vanilla             [+ C  ]
x86                 [+ C  ]
xml                 [+    ]
xml2                [+  D ]
xmms                [+  D ]
xosd                [+ C  ]
xv                  [+ CD ]
xvid                [+ C  ]
zlib                [+ CD ]

# euse -a -l
bitmap-fonts        [+  D ]
font-server         [+  D ]
fortran             [+  D ]
gimpprint           [+ C  ]
imlib2              [+    ]
md5sum              [+ C  ]
mpeg4               [+ C  ]
nvidia              [+ C  ]
offensive           [+    ]
truetype            [+ CD ]
truetype-fonts      [+  D ]
type1-fonts         [+  D ]

(איפשור דגל שימוש)
#  euse -E 3dfx
/etc/make.conf was modified, a backup copy has been placed at /etc/make.conf.euse_backup

(הקובץ etc/make.conf/ לאחר הפקודה)
USE="alsa acpi apache2 -arts cups cdr crypt cscope -doc ethereal fbcon gd \
    gif gimpprint gnome gpm gstreamer gtk2 gtkhtml imlib imlib2 \
    innodb -java javascript jpeg libg++ libwww mad mbox md5sum \
    mikmod mmx motif mozilla mpeg mpeg4 mysql ncurses nvidia \
    oggvorbis odbc offensive opengl pam pdflib perl png python \
    quicktime readline sdl spell sse ssl svga tcltk tiff truetype usb \
    vanilla X xml2 xmms xosd xv xvid x86 zlib 3dfx"

(ניטרול דגל שימוש)
#  euse -D 3dfx
/etc/make.conf was modified, a backup copy has been placed at /etc/make.conf.euse_backup

(הקובץ etc/make.confלאחר הפקודה)
USE="alsa acpi apache2 -arts cups cdr crypt cscope -doc ethereal fbcon gd \
    gif gimpprint gnome gpm gstreamer gtk2 gtkhtml imlib imlib2 \
    innodb -java javascript jpeg libg++ libwww mad mbox md5sum \
    mikmod mmx motif mozilla mpeg mpeg4 mysql ncurses nvidia \
    oggvorbis odbc offensive opengl pam pdflib perl png python \
    quicktime readline sdl spell sse ssl svga tcltk tiff truetype usb \
    vanilla X xml2 xmms xosd xv xvid x86 zlib -3dfx"

# revdep-rebuild -p

Checking reverse dependencies...
Packages containing binaries and libraries broken by any package update,
will be recompiled.

Collecting system binaries and libraries... done.
  (/root/.revdep-rebuild.1_files)

Collecting complete LD_LIBRARY_PATH... done.
  (/root/.revdep-rebuild.2_ldpath)

Checking dynamic linking consistency...
  broken /usr/lib/ao/plugins-2/libarts.so (requires libartsc.so.0)
  broken /usr/lib/kde3/libkpresenterpart.so (requires libartskde.so.1 libqtmcop.so.1
         libsoundserver_idl.so.1 libkmedia2_idl.so.1 libartsflow.so.1 libartsflow_idl.so.1 libmcop.so.1)
  broken /usr/lib/ruby/site_ruby/1.8/i686-linux/fox.so (requires libFOX-1.0.so.0)
  broken /usr/lib/xine/plugins/1.0.0/xineplug_ao_out_arts.so (requires libartsc.so.0)
  broken /usr/lib/perl5/vendor_perl/5.8.0/i686-linux/auto/SDL_perl/SDL_perl.so (requires libSDL_gfx.so.0)
  broken /usr/lib/libloudmouth-1.so.0.0.0 (requires libgnutls.so.10)
  broken /usr/bin/k3b (requires libartskde.so.1 libqtmcop.so.1 libsoundserver_idl.so.1 libkmedia2_idl.so.1
         libartsflow.so.1 libartsflow_idl.so.1 libmcop.so.1)
  broken /usr/bin/lua (requires libhistory.so.4)
  broken /usr/bin/lyx (requires libAiksaurus-1.0.so.0)
  broken /usr/bin/luac (requires libhistory.so.4)
  broken /usr/bin/avidemux2 (requires libartsc.so.0)
  broken /usr/bin/pptout (requires libxml++-0.1.so.11)
  broken /usr/bin/xml2ps (requires libxml++-0.1.so.11)
 done.
  (/root/.revdep-rebuild.3_rebuild)

Assigning files to ebuilds... done.
  (/root/.revdep-rebuild.4_ebuilds)

Evaluating package order... done.
  (/root/.revdep-rebuild.5_order)

All prepared. Starting rebuild...
emerge --oneshot --nodeps -p =app-cdr/k3b-0.11.14 =app-office/koffice-1.3.2 =app-office/lyx-1.3.4 \
      =app-office/passepartout-0.2 =dev-lang/lua-5.0.2 =dev-ruby/fxruby-1.0.29 =media-libs/libao-0.8.5 \
      =media-libs/xine-lib-1_rc5-r3 =media-video/avidemux-2.0.26 =net-libs/loudmouth-0.16 

These are the packages that I would merge, in order:

Calculating dependencies ...done!
[ebuild   R   ] app-cdr/k3b-0.11.14
[ebuild   R   ] app-office/koffice-1.3.2
[ebuild   R   ] app-office/lyx-1.3.4
[ebuild   R   ] app-office/passepartout-0.2
[ebuild   R   ] dev-lang/lua-5.0.2
[ebuild   R   ] dev-ruby/fxruby-1.0.29
[ebuild   R   ] media-libs/libao-0.8.5
[ebuild   R   ] media-libs/xine-lib-1_rc5-r3
[ebuild   R   ] media-video/avidemux-2.0.26
[ebuild   R   ] net-libs/loudmouth-0.16

Now you can remove -p (or --pretend) from arguments and re-run revdep-rebuild.