I'm more familiar with Fedora where I do something like this. It
should be possible to do the same in Ubuntu with the appropriate
apt-get commands.
1. List all packages with their names only (no versions) on both the
old system and newly installed system, assuming the new system is
booted and the old system is mounted at /mnt/oldroot.
Alternatively, do the first command (without the --root parameter)
when booted to the old version and save the file somewhere:
rpm -qa --qf='%{name}\n' --root=/mnt/oldroot | sort -u > old-pkglist.txt
rpm -qa --qf='%{name}\n' | sort -u > new-pkglist.txt
2. Compare the files and save that output:
diff -b -U0 {old,new}-pkglist.txt > old-new-diff.txt
grep ^- old-new-diff.txt | cut -c2- > missing-from-new.txt
grep ^+ old-new-diff.txt | cut -c2- > only-in-new.txt
3. Now go through the list and install what you want. I usually do
this step manually rather than using some automated script, since
there are many changes I don't necessarily want, such as shared
libraries. All I really care about is applications/commands/utilities.
I go through the lists, reading the diff in one window and installing
stuff I want in another:
dnf install a b c d ...
and/or this which installs a package and all of its subpackages
except development and debug subpackages. This is great when a
package has a bunch of plugins I want:
dnf --exclude='*devel*' --exclude='*debug*' install foo-\* ...
Or you could curate the list, e.g. edit missing-from-new.txt
keeping only the lines you care about, then automatically install
everything that is in the curated list:
cat missing-from-new-curated.txt | xargs dnf -y install
> >> On Thu, Jan 13, 2022 at 3:47 PM gmcaplan--- via WLUG
> >> <wlug(a)lists.wlug.org> wrote:
> >>
> >> I was hoping to attend, but it looks like I will not be able to.
> >> I hope it will be recorded because I, too, would like to learn about
> >> emacs.
> >> Also, I have two questions:
> >> 1. I am running Ubuntu 18.04 LTS. When I update to ver. 20 or 22, I
> >> would prefer to do a "clean" re-install, but I have a question. Does
> >> that mean I must get a list of all my installed software and
> >> re-install
> >> them one at a time after I upgrade the OS? If so, is there an
> >> easy way
> >> for me to get the list?