Comparing packages between ISOs or between an ISO and those locally installed using 'isocomparepkgs.sh'

This is the first of three posts introducing a couple of new 'ISO' tools that I've developed to complement my 'isorespin.sh' script.

The first tool is 'isocomparepkgs.sh' which is a script to compare installed packages between two Ubuntu (or Ubuntu flavour), Linux Mint, neon, elementary, BackBox or Peppermint desktop ISOs or Ubuntu live server ISOs or between one such ISO and the locally installed packages on the system where the script is run.

linuxium@LINUXIUM:~$ isocomparepkgs.sh
Usage: isocomparepkgs.sh <ISO> [<ISO>]
linuxium@LINUXIUM:~$

The usage syntax is straightforward: you either run the script against two ISOs to get a package comparison of those installed in each or you run the script against one ISO to get a comparison of packages in the ISO verses those locally installed.

For example, say you want to see the package difference between the original Ubuntu 18.04 ISO and the latest point release of 18.04.4. Simply enter the command:

isocomparepkgs.sh ubuntu-18.04-desktop-amd64.iso ubuntu-18.04.4-desktop-amd64.iso

The resultant output looks like this:

with the logfile 'isocomparepkgs.log' also including a side-by-side comparison:

It is important to note that the script only shows the difference between installed packages based on their name and not their version or release. Also it only shows packages and not userspace file differences. 

So the difference between a respun Ubuntu 18.04.4 ISO using the 'atom' option and the original ISO only shows the additional bluetooth package and not the wifi and ALSA UCM files which were also added as a result of respinning:

When comparing packages in an ISO with those locally installed it is important to remember than an ISO also includes several packages used only as part of the installation process:

and that the list of locally installed packages also includes all the dependent packages which can make it difficult to determine the actual packages used in the install commands:

which is a why the second post in this series may be of interest.

The initial release of 'isocomparepkgs.sh' can be downloaded from here.

Please donate if you find the script useful using the following link http://goo.gl/nXWSGf as everything helps with development costs.