emerge: the other white meat (command-line interface to the Portage system)
Usage:
   emerge [ options ] [ action ] [ ebuild | tbz2 | file | @set | atom ] [ ... ]
   emerge [ options ] [ action ] < @system | @world >
   emerge < --sync | --metadata | --info >
   emerge --resume [ --pretend | --ask | --skipfirst ]
   emerge --help
Options: -[abBcCdDefgGhjkKlnNoOpPqrsStuvVw]
          [ --color < y | n >            ] [ --columns    ]
          [ --complete-graph             ] [ --deep       ]
          [ --jobs JOBS ] [ --keep-going ] [ --load-average LOAD            ]
          [ --newrepo   ] [ --newuse     ] [ --noconfmem  ] [ --nospinner   ]
          [ --oneshot   ] [ --onlydeps   ] [ --quiet-build [ y | n ]        ]
          [ --reinstall changed-use      ] [ --with-bdeps < y | n >         ]
Actions:  [ --depclean | --list-sets | --search | --sync | --version        ]

   For more help consult the man page.