清除并重新安装软件包的命令

有时，某个软件包损坏了，需要从头开始重新安装。我可以用apt-get purge后面apt-get install，后来我有看，如果任何相关程序包卸载得到，记得重新安装它们。

是否有清除和重新安装程序包的命令来处理依赖关系？如果某个软件包取决于要重新安装的软件包，则应将该软件包留在原处，或者也应重新安装。

不建议这样做，但是您可以进行底切apt并直接转到dpkg。

例如，采用postfix和postfix-dev：

$ sudo apt-get purge postfix
Reading package lists... Done
Building dependency tree
Reading state information... Done.
The following packages will be REMOVED:
  postfix* postfix-dev*
0 upgraded, 0 newly installed, 2 to remove and 99 not upgraded.
After this operation, 4449 kB disk space will be freed.
Do you want to continue? [Y/n] n
Abort.

现在我们使用dpkg清除postfix而不删除依赖项：

$ sudo dpkg --purge --force-depends postfix
dpkg: postfix: dependency problems, but removing anyway as you requested:
 postfix-dev depends on postfix (>= 3.1.0-0).
 postfix-dev depends on postfix (<< 3.1.0.0-0).
 postfix-dev depends on postfix (>= 3.1.0-0).
 postfix-dev depends on postfix (<< 3.1.0.0-0).

(Reading database ... 293223 files and directories currently installed.)
Removing postfix (3.1.0-3) ...
Purging configuration files for postfix (3.1.0-3) ...
Processing triggers for libc-bin (2.23-0ubuntu5) ...
Processing triggers for man-db (2.7.5-1) ...

现在重新安装postfix：

$ sudo apt-get install postfix
Reading package lists... Done
Building dependency tree
Reading state information... Done
Suggested packages:
  procmail postfix-mysql postfix-pgsql postfix-ldap postfix-pcre sasl2-bin dovecot-common postfix-cdb postfix-doc
The following NEW packages will be installed:
  postfix
0 upgraded, 1 newly installed, 0 to remove and 99 not upgraded.
Need to get 0 B/1152 kB of archives.
After this operation, 3697 kB of additional disk space will be used.
Preconfiguring packages ...
Selecting previously unselected package postfix.
(Reading database ... 293035 files and directories currently installed.)
Preparing to unpack .../postfix_3.1.0-3_amd64.deb ...
Unpacking postfix (3.1.0-3) ...
...