例えばdeborphanは使われていないと思われるパッケージを検索して標準出力に表示してくれる。これの各行をaptitude whyへのコマンドライン引数としたい。
# deborphan --guess-all libgsl0-dev libmail-imapclient-perl libmail-pop3client-perl libunicode-japanese-perl libsigc++-dev libio-compress-base-perl libsigc++-2.0-dev libio-compress-zlib-perl libcompress-raw-zlib-perl libperl-dev libidn11-dev python-dev liblua5.1-0-dev libmime-perl libclass-factory-util-perl libdatetime-format-strptime-perl libwww-mechanize-shell-perl libgtk2.0-dev libdatetime-format-mail-perl libaspell-dev libtest-exception-perl liblocale-maketext-lexicon-perl libsoap-lite-perl libdatetime-format-w3cdtf-perl libncursesw5-dev libxml-sax-writer-perl comerr-dev libgnutls-dev libxml-twig-perl libtest-www-selenium-perl libjson-perl netcat ruby1.8-dev
以下のようにしてxargsにリダイレクトすれば良い。xargs --max-args 1とすることで、xargsは標準入力を受け取り、これの各行を引数としてaptitude whyに与える。
# deborphan --guess-all | xargs --max-args 1 aptitude why Unable to find a reason to install libgsl0-dev. i debhelper Depends po-debconf i A po-debconf Suggests libmail-box-perl p libmail-box-perl Suggests libmail-imapclient-perl (>= 3) Unable to find a reason to install libmail-pop3client-perl. Unable to find a reason to install libunicode-japanese-perl. Unable to find a reason to install libsigc++-dev. Unable to find a reason to install libio-compress-base-perl. i libsigc++-2.0-dev Suggests libsigc++-2.0-doc p libsigc++-2.0-doc Recommends libsigc++-2.0-dev Unable to find a reason to install libio-compress-zlib-perl. i libio-compress-zlib-perl Depends libio-compress-perl p libio-compress-perl Depends libcompress-raw-zlib-perl (>= 2.024) Unable to find a reason to install libperl-dev. i mercurial Suggests qct p qct Depends mercurial | git-core | bzr | monotone | subversion | cvs p bzr Suggests python-pycurl p python-pycurl Suggests libcurl4-gnutls-dev p libcurl4-gnutls-dev Depends libidn11-dev i installation-report Recommends reportbug p reportbug Suggests python-gtk2 p python-gtk2 Depends python-numpy (< 1:1.5) p python-numpy Suggests python-dev Unable to find a reason to install liblua5.1-0-dev. Unable to find a reason to install libmime-perl. Unable to find a reason to install libclass-factory-util-perl. Unable to find a reason to install libdatetime-format-strptime-perl. Unable to find a reason to install libwww-mechanize-shell-perl. i wl Suggests mhc p mhc Recommends mhc-utils p mhc-utils Depends libpisock9 p libpisock9 Suggests evolution p evolution Suggests bug-buddy p bug-buddy Recommends gnome-dbg p gnome-dbg Depends anjuta-dbg p anjuta-dbg Depends anjuta (= 2:2.32.0.0-5) p anjuta Suggests libgtk2.0-dev i liblocale-maketext-lexicon-perl Suggests libtemplate-perl (>= 2.20) p libtemplate-perl Suggests libtemplate-plugin-xml-perl p libtemplate-plugin-xml-perl Depends libxml-rss-perl p libxml-rss-perl Depends libdatetime-format-mail-perl Unable to find a reason to install libaspell-dev. Unable to find a reason to install libtest-exception-perl. Unable to find a reason to install liblocale-maketext-lexicon-perl. i cdbs Suggests devscripts p devscripts Recommends libsoap-lite-perl i liblocale-maketext-lexicon-perl Suggests libtemplate-perl (>= 2.20) p libtemplate-perl Suggests libtemplate-plugin-xml-perl p libtemplate-plugin-xml-perl Depends libxml-rss-perl p libxml-rss-perl Depends libdatetime-format-w3cdtf-perl i aptitude Depends libcwidget3 i A libcwidget3 Suggests libcwidget-dev p libcwidget-dev Depends libncursesw5-dev Unable to find a reason to install libxml-sax-writer-perl. i debconf Suggests libqtgui4-perl p libqtgui4-perl Depends libqt4-sql (>= 4:4.5.3) p libqt4-sql Suggests libqt4-dev p libqt4-dev Suggests libpq-dev p libpq-dev Depends comerr-dev i debconf Suggests libqtgui4-perl p libqtgui4-perl Depends libqt4-sql (>= 4:4.5.3) p libqt4-sql Suggests libqt4-dev p libqt4-dev Suggests unixodbc-dev p unixodbc-dev Suggests libqt3-mt-dev p libqt3-mt-dev Depends libcups2-dev p libcups2-dev Depends libgnutls-dev i r-base Depends r-base-core (>= 2.11.1-6) i A r-base-core Depends xdg-utils i A xdg-utils Recommends iceweasel | www-browser p galeon Provides www-browser p galeon Recommends gnome-control-center p gnome-control-center Recommends gnome-session p gnome-session Depends gnome-panel (>= 2.26) p gnome-panel Recommends gnome-applets (>= 2.12.1-1) p gnome-applets Depends liboobs-1-4 (>= 2.30.0) p liboobs-1-4 Depends system-tools-backends (>= 2.9.2) p system-tools-backends Depends libnet-dbus-perl p libnet-dbus-perl Depends libxml-twig-perl Unable to find a reason to install libtest-www-selenium-perl. i cdbs Suggests devscripts p devscripts Recommends libjson-perl i cdbs Suggests devscripts p devscripts Recommends lsb-release i A lsb-release Suggests lsb p lsb Suggests lsb-printing p lsb-printing Depends foomatic-filters p foomatic-filters Recommends foomatic-db-engine (>= 4.0) p foomatic-db-engine Recommends netcat i ruby Suggests ruby-dev p ruby-dev Depends ruby1.8-dev