apt-get remove packagename
will remove the binaries, but not the configuration or data files of the package
packagename. It will also leave dependencies installed with it on installation time untouched.
apt-get purge packagename or
apt-get remove --purge packagename
will remove about everything regarding the package
packagename, but not the dependencies installed with it on installation. Both commands are equivalent.
Particularly useful when you want to 'start all over' with an application because you messed up the configuration. However, it does not remove configuration or data files residing in users home directories, usually in hidden folders there. There is no easy way to get those removed as well.
removes orphaned packages, i.e. installed packages that used to be installed as an dependency, but aren't any longer. Use this after removing a package which had installed dependencies you're no longer interested in.
aptitude remove packagename or
aptitude purge packagename (likewise)
will also attempt to remove other packages which were required by
packagename on but are not required by any remaining packages.
And many more exist. Lower-level
dpkg-commands can be used (advanced), or GUI tools like Muon, Synaptic, Software Center, etc. There's no single 'correct way' of removing applications or performing other tasks interacting with your package management.
The list you found are just examples. Make sure you understand the meanings and try out what it wants to do before accepting the action (you need to press
Y before it actually performs the actions as proposed).
The asterisk version in the question is probably wrong;
apt-get accepts a regular expression and not a glob pattern as the shell. So what happens with
sudo apt-get remove application*
is the following:
The shell try to expand
application* looking at the files in the current directory. If (as normally is the case) find nothing, it returns the glob patter unaltered (supposing
bash with default behavior here ---
zsh will error out).
apt-get will remove the packages whose name contains a string that satisfy the regular expression
application*, that is,
applicatio followed by an arbitrary number of
to see how this can be dangerous, try (without root for double safety)
apt-get -s remove "wine*" (
-s will simulate the thing instead of doing it) --- it will say is going to remove all packages that has "win" in their name and the dependant, almost all system...
Probably, the command that was meant is really
sudo apt-get remove "^application.*"
(note the quotes and the dot) which will remove all packages whose name starts with
sudo updatedb # <-- updates the locate database (index). harmless
sudo locate application # <-- locates the file 'application'. harmless
sudo rm -rf (file/folder name) # <-- removes files/dirs recursively. dangerous.
are completely outside the scope of the package management. Do not remove files belonging to packages without using the package management! It will get confused and is the wrong way to do things.
If you don't know to which package a file belongs, try this:
dpkg -S /path/to/file