Ok, I understand, now. I just leave multiple desktops in place and switch between them as I want. But perhaps you have reasons to do it as you do. That is one thing I really appreciate about Linux, the fact that there are many, many ways to accomplish almost everything and that what is right and works for me may not be what works best for you.

Your scripting style is irrelevant so long as it gets the job done for you. And one tenet the Unix/Linux Philosophy is, "automate everything," which is what you have done.

On 02/26/2015 09:21 AM, Niki Kovacs wrote:

Le 26/02/2015 15:00, David Both a écrit :

...

Perhaps I have not been following closely enough, but why go backwards? Why not start with a "minimal" installation and then add only those packages that are needed for your situation?

Here's why.

I'm currently experimenting with CentOS on my workstation, trying out different desktop environments like GNOME3, KDE, MATE, Xfce. But at the same time, I'm also working on that same workstation, for example developing websites on a local LAMP stack, using multimedia apps like Audacity to edit some audio tracks for my training courses, etc.

When switching from one desktop environment to another for the sake of trying it out, there's always tons of cruft on the system, even after a yum groupremove "Old Desktop Environment". And I don't want to do a fresh reinstallation, because I have all my data and files in place, and this is a RAID 1 installation, so it's not exactly trivial to reinstall and put everything back in place.

Anyway, I spent a couple hours experimenting, and I found a satisfying solution. It's not very elegant, but it works. Here goes.

1. First, make a list of the packages contained in a minimal installation.

This is easy, since I can do a minimal installation in a virtual guest, and then run the following little script:

#!/bin/bash # # create_package_list.sh # # (c) Niki Kovacs, 2014

TMP=/tmp RPMLIST=$TMP/rpmlist.txt PKGLIST=$TMP/pkglist.txt rm -f $RPMLIST $PKGLIST rpm -qa | sort > $RPMLIST sed 's/-[^-]*-[^-]*.[^.]*.[^.]*$//' $RPMLIST > $PKGLIST

2. I copy that package list to the 'core' file in my Git repo and run the

following script on the system I want to prune:

#!/bin/bash # # purge_system.sh # # (c) Niki Kovacs, 2014

CWD=$(pwd) TMP=/tmp

RPMLIST=$TMP/rpmlist.txt PKGLIST=$TMP/pkglist.txt PKGINFO=$TMP/pkg_database

rpm -qa | sort > $RPMLIST

sed 's/-[^-]*-[^-]*.[^.]*.[^.]*$//' $RPMLIST > $PKGLIST

PACKAGES=$(egrep -v '(^#)|(^\s+$)' $PKGLIST)

rm -rf $RPMLIST $PKGLIST $PKGINFO mkdir $PKGINFO

# Create core package database echo echo "+==================================" echo "| Creating core package database..." echo "+==================================" echo sleep 3 CORE=$(egrep -v '(^#)|(^\s+$)' $CWD/../pkglists/core) for PACKAGE in $CORE; do printf "." touch $PKGINFO/$PACKAGE done

unset CRUFT

# Check installed packages against core package database echo echo echo "+========================================================" echo "| Checking for packages to be removed from your system..." echo "+========================================================" echo sleep 3 for PACKAGE in $PACKAGES; do if [ -r $PKGINFO/$PACKAGE ]; then continue else printf "." CRUFT="$CRUFT $PACKAGE" fi done

echo echo

# Remove all non-core packages yum remove $CRUFT

I've tested this a few times, and it works as expected. I know my scripting style is a bit hodge-podge. If you have a more elegant solution, I'm always open for suggestions.

Cheers,

Niki

--

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David P. Both, RHCE Millennium Technology Consulting LLC Raleigh, NC, USA 919-389-8678

dboth@millennium-technology.com

www.millennium-technology.com www.databook.bz - Home of the DataBook for Linux DataBook is a Registered Trademark of David Both

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On Fri, Feb 27, 2015 at 08:36:58AM +0100, Niki Kovacs wrote:

Le 26/02/2015 15:53, David Both a écrit :

...

Ok, I understand, now. I just leave multiple desktops in place and switch between them as I want. But perhaps you have reasons to do it as you do. That is one thing I really appreciate about Linux, the fact that there are many, many ways to accomplish almost everything and that what is right and works for me may not be what works best for you.

I find that it's quite easy to get a minimal desktop going. I tend to use a custom compiled dwm, but this will work with most window managers.

http://srobb.net/minimaldesktop.html