Re: [gentoo-user] The difference between 'emerge --update xyz' and 'emerge xyz'

[Pandu Poluan]

On Mon, Mar 28, 2011 at 22:26, Florian Philipp <lists@×××××××××××.net> wrote:
>
> Am 28.03.2011 16:50, schrieb Pandu Poluan:
> > Hello list!
> >
> > Please bear awhile with the Gento n00b here...
> >
> > If I have a package 'xyz-1.1.0' already installed, and there's a newer
> > 'xyz-1.2.0', what's the difference between 'emerge --update xyz' and
> > 'emerge xyz'?
> >
> > The latter I saw also pulled in and installed the latest version. So,
> > I am confused as to the difference.
> >
> > Thank you for your explanation.
> >
> > Rgds,
> >
> >
>
> A simple `emerge xyz` re-emerges xyz even if no update is necessary.
>
> Additionally, it adds the package xyz to your @world set. That is a list
> of packages that you want to keep. If xyz has been installed only
> because it is a dependency of another package and it is not part of
> @world, `emerge --depclean` would uninstall the package when it is no
> longer needed.
>
> As an example:
> Lets say, you install gnome-base/gnome. This will pull in all kinds of
> packages (the whole Gnome desktop environment). Now you decide to remove
> gnome. Then you can call `emerge --depclean gnome` to remove gnome
> itself and then `emerge --depclean` to get rid of everything else that
> is no longer needed.
>
> If you want to re-emerge a package no matter if there is an update or
> not but you do not want to add it to your @world set, call `emerge
> --oneshot xyz` or shorter: `emerge -1 xyz`. For example, this is
> necessary if xyz is a kernel module and you just installed ner kernel
> sources.
>
> A few notes:
> Your @world set is contained in /var/lib/portage/world. You can edit
> this file directly to remove or add packages.
>
> `emerge --depclean <package>` only removes the package if it is no
> longer needed by other packages. This is safer than calling `emerge
> --clean <package>`.
>
> Do not call `emerge --depclean` on its own. Call `emerge --ask --verbose
> --depclean` or shorter `emerge -avc`. Check all packages to make sure
> you do not remove anything you still need, for example portage itself.
>
> If you call `emerge --pretend --verbose --depclean <package>` (short:
> `emerge -pvc <package>`), portage will print a list of packages that
> depend on the package you gave as a parameter. This is more accurate
> than for example `equery depends <package>`.
>
> Hope this helps,
> Florian Philipp
>

Thanks! Very clear explanation, and very helpful!

Rgds,
--
Pandu E Poluan
~ IT Optimizer ~
Visit my Blog: http://pepoluan.posterous.com