FreeBSDのportsのバージョンアップできるソフトウェアをpkg_versionコマンドで調べる方法

pkg_version -v -l '<'

pkg_version -v -l '<'
GraphicsMagick-1.1.6_3              <   needs updating (port has 1.1.10)
ImageMagick-nox11-6.3.3.5           <   needs updating (port has 6.3.6.9)
ORBit2-2.14.3                       <   needs updating (port has 2.14.10)
apache-ant-1.6.5_1                  <   needs updating (port has 1.7.0_1)
apachetop-0.12.6                    <   needs updating (port has 0.12.6_1)
apel-emacs21-10.6                   <   needs updating (port has 10.7_1)
apr-gdbm-db42-1.2.8_1               <   needs updating (port has 1.2.8_2)
atk-1.12.3                          <   needs updating (port has 1.20.0)
autoconf-2.13.000227_5              <   needs updating (port has 2.13.000227_6)
autoconf-2.53_3                     <   needs updating (port has 2.61_2)

pkg_version -l '<'
GraphicsMagick-1.1.6_3              <
ImageMagick-nox11-6.3.3.5           <
ORBit2-2.14.3                       <
apache-ant-1.6.5_1                  <
apachetop-0.12.6                    <
apel-emacs21-10.6                   <
apr-gdbm-db42-1.2.8_1               <
atk-1.12.3                          <
autoconf-2.13.000227_5              <
autoconf-2.53_3                     <