“update-alternatives”中的优先级是什么意思？

Question

优先级在 中是什么意思update-alternatives？

优先级值越小代表什么？

优先级与默认值“*”有何关系和区别？

谢谢。例如：

$ sudo update-alternatives --config java
There are 4 choices for the alternative java (providing /usr/bin/java).

  Selection    Path                                           Priority   Status
------------------------------------------------------------
  0            /usr/lib/jvm/java-6-openjdk-i386/jre/bin/java   1061      auto mode
  1            /usr/bin/gij-4.6                                1046      manual mode
  2            /usr/lib/jvm/java-6-openjdk-i386/jre/bin/java   1061      manual mode
* 3            /usr/lib/jvm/java-7-openjdk-i386/jre/bin/java   1051      manual mode
  4            /usr/lib/jvm/jdk1.7.0_67/bin/java               1         manual mode

Answer 1

从man update-alternatives：

Each alternative has a priority associated with it.  When a link  group  is  in  automatic
mode,  the  alternatives  pointed  to by members of the group will be those which have the
highest priority.

它可以是任何整数，甚至是负数（请参阅手册页中的示例）。

如果手动设置了替代方案，则优先级与默认值无关。