Hacking_and_Penetration_Testing_with_Low_Power_Devices

62 CHAPTER 4 Filling the toolbox
on the face of it this might seem like a bad thing, it is actually fine. This function is
only called a few times from a script that is likely only run once. The simpler script is
preferred to an optimized one in this case. Second, there are other display managers
that you could use such as JWM or IceWM that might yield better performance.
Third, you can set it up so that only a particular user has a graphical desktop by running
the script as that user. This would free up resources used by an unused windowing
system on drones but still allow graphical programs to be run if needed. Finally,
we have learned several powerful shell scripting techniques in this small script that
we will use in our own scripts later.
ADDING TOOLS THE EASY WAY
One of the primary reasons for selecting Ubuntu as a base operating system is that it
has extremely good repository support for hacking tools. In cases where packages are
not available in standard repositories (sometimes due to licensing issues), Debian
package files are often available. Creating a Christmas list of tools and then installing
them starting with the easiest way and working toward harder methods until we are
successful seems to be a sensible approach.
USING REPOSITORIES
If you know the name of a package you want to install and it is in your repositories,
this is easily done using the command sudo apt-get install . If the
package is already installed, you will be informed of such. You will also be told
if the package isn’t found in your currently configured repositories. If the package
is available, you may be prompted on whether to install it if it requires additional
packages to be installed. Adding the -y flag to the apt-get command (sudo aptget
-y install ) will automatically answer yes to this prompt.
You can update the local package directory and upgrade all installed packages by
executing the command sudo apt-get update && sudo apt-get upgrade. The && is a
logical AND operator. Unlike the logical OR we encountered previously, expressions
on either side of the && will always be run. Furthermore, the command after
the && is only run after the command before the && completes. It is a good idea to
run this command before installing any new software.
If you are uncertain of an exact package name or have no idea which package
contains a certain tool, you can use apt-cache search to find
candidate packages. Note that sudo is not required here as anyone is allowed to look
at the package directory. Unfortunately, in some cases, you might end up with a lot of
obviously wrong packages whose names or contained tools just happen to contain
your search string. Grep is your friend in these cases. For example, apt-cache
search gnome returns hundreds of result. Piping the results to grep '^gnome' limits
results to those that start with the string “gnome.” The command apt-cache search
gnome j grep '^gnome' returns only a handful of results.