Nook: install Nano text editor

Disclaimer: this post is addressed to advanced users, that have experience with Linux command line interface, and that are confortable connecting to Nook using ADB (or telnet/ssh). The text editor Nano is not accessible by Nook (android) user interface.

The linux version installed on Nook firmware lacks any kind of text editor (nano, vi, emacs, and so on), normally present on linux distributions.
Having a text editor is really useful for advanced users, in order to quickly show and edit configuration files. Just to make some example: wifi configuration (wpa_supplicant.conf); startup configuration (init.rc).
Nano is a really simple to use editor, and it's easily installable on Nook. Of course, a rooted Nook is necessary; but if you don't have a rooted Nook, you probably will not need any linux CLI text editor.

Installation procedure:

1. download and unzip nano;
2. download terminfo;
3. copy both files to your Nook, using adb;
4. move nano to folder /system/bin;
5. set appropriate owner and permission to nano executable:
   chown system.system /system/bin/nano
   chmod 755 /system/bin/nano
6. unzip terminfo and set correct permission:
   busybox tar -xzvf terminfo.tar.gz -C /
   chmod -R 0755 /system/etc/terminfo
   chmod -R 0644 /system/etc/terminfo/?/*
7. set the following env variables:
   export TERM=xterm
   export TERMINFO=/system/etc/terminfo
8. now you should be able to launch nano from your shell:
   nano <filename>
9. (optional) you need to set the env variable of step 7) each time you launch a shell; therefore, it could be convenient to set them automatically during initialization of Nook, adding the following two lines to file /init.rc (about at the start of the file itself, where a lot of env variables are set):
   export TERM xterm
   export TERMINFO /system/etc/terminfo

That's it!