Working with apt-get and dpkg package manager tools of 'Debian'
First of all we are going to work with Apt-get package manager. For those who are already familiar with Yum of Red Hat based distros may find this quite identical tool. Apt-get pulls and installs packages from the online repository to ease your pain to find, download and install packages and its dependency manually.
You have to be root using for the following hands-on, Let's get started:
root@yogeshkk21:~# apt-get update
This command pulls package information from repository server and caches the same locally
root@yogeshkk21:~# apt-cache search nginx
We can search for a specific package in the entire cache using this command
root@yogeshkk21:~# apt-get install nginx
This command is to install a package
root@yogeshkk21:~# which nginx
To verify nginx is installed
root@yogeshkk21:~# apt-cache search apache2
Let's search for Apache2 package as well
root@yogeshkk21:~# apt-get install apache2
And Install it same as nginx
root@yogeshkk21:~# apt-get remove ngnix
Now, let's learn How to remove it
root@yogeshkk21:~# apt-get remove --purge nginx
apt-get remove only removes the binary, but keeps associated library and configuration files. So to remove everything, use purge.
root@yogeshkk21:~# apt-get autoremove
This command removes unnecessary packages alongside the removed package
root@yogeshkk21:~# which ngnix
Let's verify
root@yogeshkk21:~# apt-get remove apache2 ; apt-get autoremove apache2
This removed apache2 package along with unnecessary packages of it
root@yogeshkk21:~# which apache2
Let's verify again
root@yogeshkk21:~# apt-get install apache2
Let us install apache2 package again
root@yogeshkk21:~# apt-get upgrade
This command allows you to upgrade any packages required for apache2
root@yogeshkk21:~# apt-get dist-upgrade
This command allows you to upgrade distribution kernel if available
Now if we talk about dpkg package manager, it's the little bit different from the apt-get. This does not pull the dependencies automatically like apt-get does. Let's see:
root@yogeshkk21:~# wget https://www.dropbox.com/download?dl=packages/ubuntu/dropbox_2015.02.12_amd64.deb
Let's try to install Dropbox application on our Ubuntu 12.04 distro.
root@yogeshkk21:~# mv download\?dl\=packages%2Fubuntu%2Fdropbox_2015.02.12_amd64.deb dropbox.deb
Let's rename this downloaded file to something more simple.
root@yogeshkk21:~# dpkg -i dropbox.deb
To install the Deb file, use -i option. Now you will see that lots of dependency errors are been thrown at you. Its simply because, dpkg can't pull all those dependency for you. So, what now? Should I download and install them manually? No, there is a way out.
root@yogeshkk21:~# apt-get update
Let's update our cache once again
root@yogeshkk21:~# apt-get -f upgrade
And this command will do the job for us. It automatically pulls all the required library packages along with other dependencies. Nice, right?
root@yogeshkk21:~# dpkg -i dropbox.deb
Now, let's try that deb file again for installation. And you will notice, it gets installed! :)
root@yogeshkk21:~# which dropbox
Let's verify! Worked well.
root@yogeshkk21:~# dpkg --get-selections
Now let's also find out, how can we list all installed packages. This command will do the magic for us.
root@yogeshkk21:~# dpkg --get-selections |grep -i dropbox
We can find specific package name from the output using grep.
root@yogeshkk21:~# dpkg --remove dropbox
Just like apt-get we have remove command as well in dpkg and it removes all binary for us.
root@yogeshkk21:~# dpkg --purge dropbox
To remove the application completely, using this command.
So that's how we can use apt-get and dpkg.
HTH ^_^
Above command is tested and worked on:
root@yogeshkk21:~# lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 12.04.5 LTS
Release: 12.04
Codename: precise
