¿Obtener detalles sobre un paquete antes de instalarlo?

Cuando escribo "mc" en mi terminal Ubuntu 14.04 obtengo un

The program 'mc' is currently not installed. You can install it by typing:
sudo apt-get install mc

¿Cómo puedo obtener detalles sobre el programa 'mc' antes de instalarlo? Quiero confirmar que ese es el archivo que quiero, y no otro.

La forma más rápida es usar un terminal apt-cachey un poco de confianza ;)

apt-cache show mc

Package: mc
Priority: optional
Section: universe/utils
Installed-Size: 1434
Maintainer: Ubuntu Developers <[email protected]>
Original-Maintainer: Debian MC Packaging Group <[email protected]>
Architecture: amd64
Version: 3:4.8.13-3
Provides: mcedit
Depends: e2fslibs (>= 1.37), libc6 (>= 2.15), libglib2.0-0 (>= 2.35.9), libgpm2 (>= 1.20.4), libslang2 (>= 2.2.4), libssh2-1 (>= 1.2.5), mc-data (= 3:4.8.13-3)
Recommends: mime-support, perl, unzip
Suggests: arj, bzip2, catdvi | texlive-binaries, dbview, djvulibre-bin, file, genisoimage, gv, imagemagick, links | w3m | lynx, odt2txt, poppler-utils, python, python-boto, python-tz, xpdf | pdf-viewer, zip
Filename: pool/universe/m/mc/mc_4.8.13-3_amd64.deb
Size: 464160
MD5sum: 8bb8f947d50bcba2f68d2b66a66963c1
SHA1: c61ad7e5581ee46619069c0435c54be5e1fc34c7
SHA256: 21557289003bd195ff5a0212a00365067c5d15f0f9767556512c09da96a012d5
Description-en: Midnight Commander - a powerful file manager
 GNU Midnight Commander is a text-mode full-screen file manager. It
 uses a two panel interface and a subshell for command execution. It
 includes an internal editor with syntax highlighting and an internal
 viewer with support for binary files. Also included is Virtual
 Filesystem (VFS), that allows files on remote systems (e.g. FTP, SSH
 servers) and files inside archives to be manipulated like real files.
Description-md5: 252a5c5aeeb7425db45357d4ab8aa55f
Homepage: http://www.midnight-commander.org
Bugs: https://bugs.launchpad.net/ubuntu/+filebug
Origin: Ubuntu

otra posibilidad es aptitude, pero generalmente debe instalarlos primero:

sudo apt-get install aptitude

Y muestre la información del paquete con aptitude show aptitude

Package: aptitude                        
State: installed
Automatically installed: no
Multi-Arch: foreign
Version: 0.6.11-1ubuntu3
Priority: optional
Section: admin
Maintainer: Ubuntu Developers <[email protected]>
Architecture: amd64
Uncompressed Size: 4.990 k
Depends: aptitude-common (= 0.6.11-1ubuntu3), libapt-pkg4.12 (>= 0.9.16), libboost-iostreams1.55.0, libc6 (>= 2.14), libcwidget3, libgcc1 (>= 1:4.1.1), libncursesw5 (>= 5.6+20070908), libsigc++-2.0-0c2a (>= 2.2.0), libsqlite3-0 (>=
         3.6.5), libstdc++6 (>= 4.9), libtinfo5, libxapian22
Recommends: aptitude-doc-en | aptitude-doc, sensible-utils, libparse-debianchangelog-perl
Suggests: tasksel, debtags, apt-xapian-index
Conflicts: aptitude
Provides: aptitude
Provided by: aptitude
Description: terminal-based package manager
 aptitude is a package manager with a number of useful features, including: a mutt-like syntax for matching packages in a flexible manner, dselect-like persistence of user actions, the ability to retrieve and display the Debian
 changelog of most packages, and a command-line mode similar to that of apt-get. 

 aptitude is also Y2K-compliant, non-fattening, naturally cleansing, and housebroken.
Homepage: http://aptitude.alioth.debian.org/

Con la GUI puede abrir el "Centro de software de Ubuntu" y buscar mco Midnight Commander.

Le dará una descripción completa del paquete. También es útil si no conoce el nombre exacto del paquete.

También puede instalar Synaptic y hacer una búsqueda similar allí.

El software también se puede instalar en el Centro de software o Synaptic sin usar la línea de comandos.

Hay muchas formas de hacer esto. La más fácil por defecto es apt-cache search.

apt-cache search <regex>

Te dará algo como esto:

$ apt-cache search cheese
cheese - tool to take pictures and videos from your webcam
gir1.2-cheese-3.0 - tool to take pictures and videos from your webcam - gir bindings
libcheese-dev - tool to take pictures and videos from your webcam - base dev
libcheese-doc - tool to take pictures and videos from your webcam - documentation
libcheese-gtk-dev - tool to take pictures and videos from your webcam - widgets dev
libcheese-gtk23 - tool to take pictures and videos from your webcam - widgets
libcheese7 - tool to take pictures and videos from your webcam - base library
cheese-common - Common files for the Cheese tool to take pictures and videos
python-pyip - Python modules for raw ip packet assembling/disassembling

Esto es una especie de privilegio para:

dpkg-query -Wf '${Package} ${binary:Summary}\n'

Excepto que dpkg-querysolo parece funcionar en cosas que ya tienes instaladas.

apt listtiene búsqueda global (en lugar de expresiones regulares), que es un poco más natural para la mayoría de los usuarios, pero aún no puede modificar el formato de salida. Sin embargo, después de mirar la fuente , puede generar el resumen:

$ apt list -o 'APT::Cmd::List-Include-Summary=1'  *cheese* 
Listing... Done
cheese/trusty 3.10.2-0ubuntu2 amd64
  tool to take pictures and videos from your webcam

cheese-common/trusty 3.10.2-0ubuntu2 all
  Common files for the Cheese tool to take pictures and videos

gir1.2-cheese-3.0/trusty 3.10.2-0ubuntu2 amd64
  tool to take pictures and videos from your webcam - gir bindings

libcheese-dev/trusty 3.10.2-0ubuntu2 amd64
  tool to take pictures and videos from your webcam - base dev

libcheese-doc/trusty 3.10.2-0ubuntu2 all
  tool to take pictures and videos from your webcam - documentation

libcheese-gtk-dev/trusty 3.10.2-0ubuntu2 amd64
  tool to take pictures and videos from your webcam - widgets dev

libcheese-gtk23/trusty 3.10.2-0ubuntu2 amd64
  tool to take pictures and videos from your webcam - widgets

libcheese7/trusty 3.10.2-0ubuntu2 amd64
  tool to take pictures and videos from your webcam - base library

Es un poco bocado con el argumento de la opción, pero podría alias esto con bastante facilidad si lo desea.

Y también aptitudepuede ayudar:

$ aptitude search cheese
p   cheese                                                                       - tool to take pictures and videos from your webcam                                     
p   cheese:i386                                                                  - tool to take pictures and videos from your webcam                                     
p   cheese-common                                                                - Common files for the Cheese tool to take pictures and videos                          
v   cheese-common:i386                                                           -                                                                                       
p   gir1.2-cheese-3.0                                                            - tool to take pictures and videos from your webcam - gir bindings                      
p   gir1.2-cheese-3.0:i386                                                       - tool to take pictures and videos from your webcam - gir bindings                      
p   libcheese-dev                                                                - tool to take pictures and videos from your webcam - base dev                          
p   libcheese-dev:i386                                                           - tool to take pictures and videos from your webcam - base dev                          
p   libcheese-doc                                                                - tool to take pictures and videos from your webcam - documentation                     
p   libcheese-gtk-dev                                                            - tool to take pictures and videos from your webcam - widgets dev                       
p   libcheese-gtk-dev:i386                                                       - tool to take pictures and videos from your webcam - widgets dev                       
p   libcheese-gtk23                                                              - tool to take pictures and videos from your webcam - widgets                           
p   libcheese-gtk23:i386                                                         - tool to take pictures and videos from your webcam - widgets                           
p   libcheese7                                                                   - tool to take pictures and videos from your webcam - base library                      
p   libcheese7:i386                                                              - tool to take pictures and videos from your webcam - base library