Install additional packages that provide Bluetooth low energy and router capabilities

Question

I want to install the following packages under 2015-05-05-raspbian-wheezy:

bluez, libcap-ng0 & radvd

pi@raspberrypi ~ $ sudo apt-get install bluez radvd libcap-ng0

then I run

pi@raspberrypi ~ $ sudo dpkg -i bluez_4.99-2_armhf.deb libcap-ng0_0.6.6-2_armhf.deb radvd_1.8.5-1_armhf.deb

but I got these errors .. any idea ?

dpkg: error processing bluez_4.99-2_armhf.deb (--install):
 cannot access archive: No such file or directory
dpkg: error processing libcap-ng0_0.6.6-2_armhf.deb (--install):
 cannot access archive: No such file or directory
dpkg: error processing radvd_1.8.5-1_armhf.deb (--install):
 cannot access archive: No such file or directory
Errors were encountered while processing:
 bluez_4.99-2_armhf.deb
 libcap-ng0_0.6.6-2_armhf.deb
 radvd_1.8.5-1_armhf.deb

Answer 1

This command:

sudo apt-get install bluez radvd libcap-ng0

Will download and install those packages. If it completes successfully, there's nothing more to do.

This command:

sudo dpkg -i bluez_4.99-2_armhf.deb

Will install that package, presuming it is in the current directory. If not, it will say "No such file or directory". Generally you should not have to use dpkg at all; it would only be in the rare case where you have a package not available in a repo but which can still be installed on your distro (sometimes people distribute independent things pre-packaged this way).

So I presume you've gotten a bit confused about how these two commands relate. apt-get essentially does what dpkg does but without you ever having to see the package file it downloaded (those are likely in the filesystem afterward, see /var/cache/apt/archives, but again, this is not something you have to use or worry about).