On 01/03/2012 11:38 AM, fred0a@free.fr wrote: > What's the way to take, to test the presence of a list of packages > and to install one package or more in case where none are already > installed ? This is handled by declaring package relationships via Depends:, Recommends:, etc. http://www.debian.org/doc/debian-policy/ch-relationships.html -- Kind regards, Michael