Difference between command-line commands regarding uninstalling Cairo-Dock?

Question

The Basis

In order to uninstall Cairo-Dock completely, @Nattgew's answer to this question says that the following should be input (inputted?) into the terminal:

sudo apt-get remove cairo-dock cairo-dock-core cairo-dock-plug-ins cairo-dock-plug-ins-data cairo-dock-data

But @Sylvain_Pineau says to input into the terminal:

sudo apt-get purge cairo-dock cairo-dock-core cairo-dock-data libgldi-dev libgldi3

And yet @Muzaffar, on the other hand, says to input into the terminal a far simpler command string:

sudo apt-get-purge cairo-dock-core

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The Questions

So my questions are as follows:

1. What is the difference between purge and remove?

2. Why do some of the above include commands that others don't necessarily include?

3. Which should I use? I just want to uninstall Cairo-Dock, config files and all. As if, you know, I had uninstalled it. Lol. I've already "uninstalled" it via the Ubuntu Software Center, and it shows it as not being installed in there as well.

4. Which, for the love of all that is computerised, is it: "input" or "inputted"? (Lmao.)

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EDIT: Listen, I'm very confused now. I don't know which of these answers is the best answer, and I honestly have no clue what I'm doing here as I'm very much a beginner with Linux in general, let alone command line. Please, I don't want to screw up my system. I just want to uninstall the programme completely, like using Revo Uninstaller on Windows. That's all I want to do.

It's probably my own inexperience here, but it seems like this is way more complicated than it needs to be...

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The Specs

• Make & Model: Dell Inspiron N5010
• Operating System: Ubuntu 15.04
• GUI Environment: Unity
• Terminal Used: Terminal (Gnome-terminal), v3.14.2-0ubuntu3

Answer 1

What is the difference between purge and remove?

remove will remove the package(s) leaving the package(s)'s configuration files; purge will remove the package(s) without leaving the package(s)'s configuration files; however their actual behavior is package-dependent: I've seen purged applications that after a reinstallation still held their old configuration.

Why do some of the above include commands that others don't necessarily include?

Because they attempt, more or less successfully (this is the difference between them) to remove the package's dependencies along with the package.

To be honest, I don't consider removing each dependency manually a good way to do that; to remove and purge a package and all of its dependencies there is a way in apt-get which will take care of the specific case properly and that will remove and purge not more and not less than what is not necessary anymore (and that is general enough that it will work for any package just by replacing the package's name):

sudo apt-get purge cairo-dock && \
sudo apt-get autoremove --purge cairo-dock

• sudo apt-get purge cairo-dock: Removes and purges cairo-dock;
• sudo apt-get autoremove --purge cairo-dock: Removes and purges each cairo-dock dependecy but those needed by other packages;

Alternatively, to keep the cairo-dock's and cairo-dock's dependencies configuration files:

sudo apt-get remove cairo-dock && \
sudo apt-get autoremove cairo-dock

Which should I do? I just want to uninstall Cairo-Dock, config files and all. As if, you know, I had uninstalled it. Lol. I've already "uninstalled" it via the Ubuntu Software Center, and it shows it as not being installed in there as well.

The first method proposed above:

sudo apt-get purge cairo-dock && \
sudo apt-get autoremove --purge cairo-dock`

It will purge cairo-dock's configuration files and remove and purge not more and not less than what is not necessary anymore.

Which, for the love of all that is computerised, is it: "input" or "inputted"?

"Inputted" sounds pretty awkward. I'd second "input": https://english.stackexchange.com/questions/30684/inputted-or-input.

Answer 2

I'll try to answer to some of your question: purge is different respect remove because it deletes also the configuration files in addition to all the packages. If you want to completely remove Cairo Dock with all the configuration file you should use purge for the motivation I said before.

Answer 3

Let's start with purge-vs-remove. Some packages include configuration files in /etc/ as part of their package. It is expected that some of these might have been edited by the user so apt remove doesn't remove them if you uninstall a package. apt purge will. Neither has any effect on user configuration files in your home directory.

Now, as for removing all these things, everything cairo-dock depends on cairo-dock-core directly or otherwise. If you remove or purge that, everything else gets removed. So that's quite smart.

However, purge will only purge configuration files for explicitly stated packages. If you purge something that takes out other packages, they will only be removed. cairo-dock-core doesn't have any configuration files. There's no point purging it.

All three seem fairly equivilent for your purposes. Targeting just cairo-dock-core is clever, but it doesn't do anything fancier.