So I'm building a
.deb, and I need to do a few post-install commands (linking libraries paths, and a few other things).
Is there a way to have it so when you do a
sudo dpkg -i <pacakage-name>.deb, a script runs?
You can execute commands after installation using the postinst shell script located in the debian folder in the source.
This is a normal shell script containing all the commands to be executed (in order) after the installation of the package. dpkg will run this automatically. So, all you need to do is create a shell script before packing your source package into a binary package, name it as 'postinst' and put it in the debian directory.
For more info, visit the Ubuntu Packaging Guide.