sudo ppa-purge -s sudo ppa-purge -s http://download.owncloud.org/download/repositories/stable/xUbuntu_15.10
Updating packages lists
W: Target Packages (Packages) is configured multiple times in /etc/apt/sources.list.d/owncloud.list:1 and /etc/apt/sources.list.d/owncloud.list:2
W: Target Translations (en_US) is configured multiple times in /etc/apt/sources.list.d/owncloud.list:1 and /etc/apt/sources.list.d/owncloud.list:2
W: Target Translations (en) is configured multiple times in /etc/apt/sources.list.d/owncloud.list:1 and /etc/apt/sources.list.d/owncloud.list:2
W: http://download.owncloud.org/download/repositories/stable/xUbuntu_15.10/Release.gpg: Signature by key BCECA90325B072AB1245F739AB7C32C35180350A uses weak digest algorithm (SHA1)
W: Target Packages (Packages) is configured multiple times in /etc/apt/sources.list.d/owncloud.list:1 and /etc/apt/sources.list.d/owncloud.list:2
W: Target Translations (en_US) is configured multiple times in /etc/apt/sources.list.d/owncloud.list:1 and /etc/apt/sources.list.d/owncloud.list:2
W: Target Translations (en) is configured multiple times in /etc/apt/sources.list.d/owncloud.list:1 and /etc/apt/sources.list.d/owncloud.list:2
PPA to be removed: ppa-purge ppa
Warning: Could not find package list for PPA: ppa-purge ppa