使用 Software Updater 是否与运行 apt-get update 和 apt-get upgrade 相同？

Question

看起来这应该是真的，但我想确定一下。谢谢！

Answer 1

简答

不，它们不一样。apt-get upgrade不处理版本之间不断变化的依赖关系，所以如果一个包改变了依赖关系，它不会被升级（它会被“阻止”）。有关更多详细信息，请参阅长答案。

使用软件更新程序和使用sudo apt-get update ; sudo apt-get dist-upgrade（注意dist-）几乎是等效的，除了一个显然是 GUI，另一个是控制台应用程序，还有一些非常小的信息差异。

长答

从man apt-get,

• apt-get upgrade：

  upgrade
             upgrade is used to install the newest versions of all packages
             currently installed on the system from the sources enumerated in
             /etc/apt/sources.list. Packages currently installed with new
             versions available are retrieved and upgraded; under no
             circumstances are currently installed packages removed, or packages
             not already installed retrieved and installed. New versions of
             currently installed packages that cannot be upgraded without
             changing the install status of another package will be left at
             their current version. An update must be performed first so that
             apt-get knows that new versions of packages are available.

  （我强调）

  这意味着具有旧版本中不需要的新依赖项的较新版本包将不会使用此方法升级（除非已安装新依赖项）。这些将显示为“保留”。

• apt-get dist-upgrade：

  dist-upgrade
         dist-upgrade in addition to performing the function of upgrade,
         also intelligently handles changing dependencies with new versions
         of packages; apt-get has a "smart" conflict resolution system, and
         it will attempt to upgrade the most important packages at the
         expense of less important ones if necessary. The dist-upgrade
         command may therefore remove some packages. The
         /etc/apt/sources.list file contains a list of locations from which
         to retrieve desired package files. See also apt_preferences(5) for
         a mechanism for overriding the general settings for individual
         packages.

  （我强调）

  这意味着使用此命令而不是upgrade，可以升级具有新（或删除）依赖项的包。

例子

两者之间差异的一个很好的例子是发布新的 Linux 内核时。这被打包到linux-image-generic始终依赖于 Linux 内核的最新包的包中。因为linux-image-generic每次内核升级都会改变依赖关系，所以upgrade不会升级它。

Answer 2

几乎是一样的，但又不完全一样。例如，当提供内核更新时，sudo apt-get update && sudo apt-get dist-upgrade需要获取这些更新。

sudo apt-get update && sudo apt-get upgrade会告诉您一些包裹已被扣留。

使用软件更新程序使一切变得无缝，您不会看到任何阻碍。